jatropha curcas l.: a potential bioenergy crop - on field research in belize
TRANSCRIPT
Università degli Studi di Padova
Facoltà di Agraria
Dipartimento di Biotecnologie Agrarie
Laurea Magistrale in Scienze e Tecnologie Agrarie
Jatropha curcas L., a potential bioenergy crop.
On field research in Belize.
Relatore:
Prof. Mario Malagoli, Università degli Studi di Padova
Correlatore:
Dr. ir. Raymond Jongschaap, Wageningen University and Research centre,
Plant Research International
Laureando:
Berardo da Schio
Matricola n° 588712
Anno Accademico 2009/2010
If you use information from this M.Sc. dissertation document, please citeand refer to:
da Schio, B., 2010. Jatropha curcas L., a potential bioenergy crop. On fieldresearch in Belize. M.Sc. dissertation. Padua University, Italy and Wageningen University and Research centre, Plant ResearchInternational, the Netherlands.
“Sub umbra floreo”.
National motto of Belize.
Table of Contents
List of Abbreviations.........................................................................................................7
Abstract............................................................................................................................11
1.Introduction..................................................................................................................13
1.1 Energy crisis and global climate...........................................................................13
1.2 Jatropha curcas L., a potential bioenergy crop....................................................18
1.2.1 Knowledge gaps in Jatropha curcas L. research..........................................28
1.2.2 Selection of knowledge gaps and justification..............................................31
1.3 Aim and objectives of the thesis...........................................................................33
2.Materials and Methods.................................................................................................35
2.1 Research at PRI Wageningen, the Netherlands.....................................................35
2.2 On field research in Belize, Central America.......................................................36
2.2.1 Climate data..................................................................................................39
2.2.2 Maya Ranch trial...........................................................................................40
2.2.3 Warrie Head trial...........................................................................................44
2.2.4 Central Farm trial..........................................................................................45
2.3 Statistical analysis.................................................................................................49
3.Results and discussions................................................................................................51
3.1 Important drivers for Jatropha curcas L. growth and development and how are
these for Belize...........................................................................................................51
3.1.1 Radiation and light interception....................................................................51
3.1.2 Temperature...................................................................................................52
3.1.3 Water.............................................................................................................53
3.1.4 Vapour pressure and wind speed...................................................................53
3.2 Response of genetically different accessions to available resources in Belize.....55
3.2.1 Seed dimension and weight...........................................................................55
3.2.2 Seed germination rate....................................................................................58
3.2.3 Biomass development at nursery stage: LA, fresh weight, taproot length....60
Table of Contents
3.3 Resources use efficiency and optimization for jatropha crop conditions in Belize..
.....................................................................................................................................63
3.3.1 Plant density..................................................................................................63
3.3.2 Plant spacing.................................................................................................64
3.3.3 Crop management.........................................................................................71
3.4 Discussions...........................................................................................................80
4.Conclusions..................................................................................................................85
5.Acknowledgements......................................................................................................89
Annex 1. Growth parameters and sustainability indicators tables...................................91
Annex 2. Experimental designs.......................................................................................99
References.....................................................................................................................107
6
List of AbbreviationsAET............... Actual Evapo-Transpiration
aft. ….............after (in Annex 1)
agr. …............ agricultural (in Annex 1)
BNMS............Belize National Meteorological Service
BT.................. Bullet Tree
CBD...............Convention on Biological Diversity
CDM..............Clean Development Mechanism
CF.................. Central Farm
COCyTECH.. Consejo de Ciencia y Tecnología
comm. …....... communication
DM................ Dry matter
DMA............. Dry matter assignment
EEP................ Energy and Environment Partnership
EM.................Effective Micro-organisms
ERA-ARD..... Agricultural Research for Development; Dimension of the European Research Area
EU..................European Union
FACT............. Fuel on Agricultural Common Technology
FAO............... Food and Agriculture Organization of the United Nations
GHG.............. Greenhouse gases
GUARD.........Galen University – Applied Research and Development for SustainabilityInstitute
HI...................Harvest index
IEA................ International Energy Agency
IPCC.............. International Panel on Climate Change
JC...................Jatropha curcas L. (in Annex 1)
LA..................Leaf Area
LAI................ Leaf Area Index
LCA............... Life Cycle Analysis
MR.................Maya Ranch
NBS............... Nucleotide Binding Site
NGO.............. Non Governmental Organization
List of Abbreviations
OAS...............Organization of the American States
OM.................Organic Matter
PET................ Potential Evapo-Transpiration
pm..................parameter (in Annex 1)
PRI.................Plant Research International
PS...................Production system (in Annex 1)
T,M,B.............Top, Middle, Bottom branches (in Annex 1)
TSDF..............Tropical Studies and Development Foundation
UB................. University of Belize
UNEP.............United Nations Environment Programme
UNDP.............United Nations Development Programme
UNFCCC.......United Nations Framework Convention on Climate Change
USD...............United States Dollar
WH................ Warrie Head
WUR..............Wageningen University and Research centre
8
Ai miei genitori,
e ai miei nonni.
Abstract
Potentials of bioenergy crop Jatropha curcas L. are investigated through field trials in
Cayo District, Belize, Central America. Crop growth and development are monitored in
two jatropha plantations of one and six years, respectively in Warrie Head and Maya
Ranch. A third plantation is set up in Central Farm, in the framework of the '1st
Coordinated Call for a Transnational Research Activity under the ERA-ARD Net:
Bioenergy – an opportunity or threat for the rural poor', in the project 'Bioenergy in
Africa and Central America – Opportunities and Risks of Jatropha and Related Crops'.
Biomass development is assessed through measurements of dry fruit yield, LAI
development, length of effective branch, seed dimensions and weight, fruit to seed ratio
and seed to kernel ratio and seed germination test in relation to different crop variables,
according to the different trials: management, such as pruning and cropping system
(monoculture, intercropping and living fence), genotype, plant spacing and plant
density. Outputs on biomass development are linked with weather variables data, kindly
provided by the National Meteorological and Hydrological service of Belize.
Results indicate that Jatropha curcas L. has promising potentials to play a decisive role
in bioenergy scenario in Belize and the Region, for the favourable pedoclimatic
situation and the availability of genetic resources.
Key words: Jatropha curcas L. – Biofuels – LAI development – Belize – Tropical
agriculture.
RiassuntoIl potenziale della coltura energetica Jatropha curcas L. viene investigato in prove di
campo nel Distretto di Cayo, Belize, America Centrale. La crescita e lo sviluppo della
coltura vengono monitorati in due piantagioni di uno e sei anni, rispettivamente a
Warrie Head e a Maya Ranch. Una terza piantagione viene messa a dimora a Central
Farm, nel contesto della '1st Coordinated Call for a Transnational Research Activity
under the ERA-ARD Net: Bioenergy – an opportunity or threat for the rural poor', nel
progetto 'Bioenergy in Africa and Central America – Opportunities and Risks of
Abstract
Jatropha and Related Crops'.
Lo sviluppo della biomassa è stimato attraverso misurazioni di: produzione di frutta,
sviluppo del LAI, lunghezza effettiva dei rami, dimensioni e peso dei semi, rapporto in
peso di frutto e seme, prove di germinazione, in relazione a variabili differenti, secondo
le diverse prove: gestione colturale, come potatura e sistema colturale (monocoltura,
consociazione e recinto verde) genotipo, spaziatura e densità. Lo sviluppo della
biomassa viene confrontato in relazione ai dati sulle variabili climatiche, gentilmente
messi a disposizione del servizio Meteorologico ed Idrologico Nazionale del Belize.
I risultati indicano che Jatropha curcas L. mostra promettenti potenziali nello scenario
bioenergetico del Belize e della Regione, in ragione della situazione pedoclimatica
favorevole e della disponibilità di risorse genetiche.
Parole chiave: Jatropha curcas L. – Biocombustibili – indice di area fogliare LAI –
Belize – Agricoltura tropicale.
12
1. Introduction
Energy availability and energy use are issues of global concern and have been under
research worldwide for a long time. Attention is mostly given to reduce energy
consumption and to detect new and renewable energy resources, in order to cope with
the world energy crisis. Two main processes are responsible for this situation: first, the
increasing population and development rates are rapidly multiplying the global energy
demand in many countries; secondly, the great share that traditional fossil fuels occupy
on the global energy consumption can hardly be sustained. In fact, the ongoing fossil
fuels depletion has reached a stage where the current reserves seem not enough for
future needs. Furthermore the role of fossil fuels on climate change and global warming
can no longer be neglected (IPCC, 2007).
1.1 Energy crisis and global climate
High fossil fuel prices, the risks of fossil fuel dependence and the increasing greenhouse
gas (GHG) emissions derived from this kind of fuels are the main reasons to find new
and renewable energy sources for the coming years (FAO, 2008). In fact the current
energy crisis is mainly due to the high dependence on fossil fuels. It is now evident that
oil consumption is drastically increasing, while the reserves are rapidly diminishing
(Dowlatabadi, 2006), so it would be more relevant to talk about oil crisis than energy
crisis. Current global trends in energy supply and consumption are patently
unsustainable: environmentally, economically and socially. That indicates a global need
to secure the supply of reliable and affordable energy and to effect a rapid
transformation to a low-carbon efficient and environmentally benign system of energy
supply. It is also clear that current energy fossil fuel consumption trend will have severe
consequences on natural ecosystems and social communities. Switching to renewable
energy will therefore reduce global warming and curb actual trends (IEA, 2006). These
are the reasons why a search for alternatives to fossil fuels, such as renewable energy
from solar, wind, water, biomass and nuclear, has been provoked.
All renewable energy options have pros and cons and a global analysis should be
undertaken for each one of them. Various aspects of renewable energies will be
1.Introduction
discussed, but nuclear energy will not be taken into consideration.
The matter of renewable energy involves different forms and sources of energy.
According to the Unified Bio-Energy Terminology definition (FAO, 2004), renewable
energy consists of energy produced and/or derived from sources infinitely renovated
(hydro, solar, wind) or generated by renewable combustibles (sustainably produced
biomass). Renewable energy offers an interesting option to reduce fossil fuels
dependence and to reach climate change mitigation and if well consciously and
sustainably managed, it may help to preserve biodiversity, water and soil reserves, as
well as human livelihoods.
Due to its importance, international actors have expressed themselves on the subject.
The United Nations Framework Convention on Climate Change (UNFCCC, 1992)
supports bioenergy as one of the “precautionary measures to anticipate, prevent or
minimize the causes of climate change”. The 1997 Kyoto Protocol to the UNFCCC
recognizes the importance of renewable energy as a contributor to mitigating climate
change, with a view to assisting developing countries in achieving sustainable
development and enabling industrialized countries to comply with their quantitative
emission targets thanks to the Clean Development Mechanism. The Convention on
Biological Diversity (UNEP, 1992) is relevant to sustainable bioenergy development as
it commits parties to biodiversity conservation, the sustainable use of its components
and the fair and equitable sharing of benefits arising from the use of genetic resources.
Many different solutions to face worldwide changes on climate and on energy demand
are available. Alternatives to fossil fuels seem in fact numerous. The appropriate
solution to alleviate fossil fuel crisis and related climatic problems may vary according
to the local situation and taking into account social, economic and environmental
spheres. An interesting option that should be seriously taken into account in relation to
the local factors is represented by biofuels produced directly or indirectly from biomass.
They have been subject of many claims and researches during the past decades, and
they are now classified by the FAO as “First-generation” and “Second-generation”
biofuels. First generation biofuels are the ones mainly derived from food-crops,
14
1.Introduction
including sugar- and starch-based bioethanol and oilseed based biodiesel; while Second
generation biofuels are the ones derived from non-food crop agricultural and forestry
products, making use of the lignin, cellulose and hemicellulose components of plants
(FAO, 2008). Both first and second generation biofuels present good opportunities but
also have negative sides. In fact, on the one hand they are a remarkable option to
combat climate change and to reduce fossil fuel dependency, while on the other hand
they can directly or indirectly affect food security and do not play a relevant role in
GHG emissions mitigation. It is important to bear in mind that biofuels often compete
for land, water and nutrient resources and they can provoke an increase of food price.
However, in an optimized setting, (local) energy supply may contribute to productivity
increase and to the prosperity of livelihoods. A way to check the effectiveness of climate
change mitigation through biofuel production and use should be found, which means
identifying tools that allow comparing energy and GHG emission balances (inputs and
outputs) and indicating if a better action is effectively accomplished. Ultimately, the
impact of biofuels on livelihood should not be disregarded.
To date, energy and GHG emission balances are of high concern as researches on this
issue provoke great discussions. To loose this worry, life cycle assessments (LCA) are
used as tools that take into account different parameters and variables to define the best
improvement on an environmental scale: impacts are evaluated after different decisions
and management actions over the whole life cycle of a specific product. Indeed, the
benefits coming from renewable energies' strategy and management implementation are
linked to many variables, as the good opportunity of favourably impacting the
environment and the farmers' livelihoods. With regard to all these concerns, a further
broad question is attracting people’s attention and animating the worldwide debate on
energy: the struggle between local and global energy. In fact, energy consumption is an
issue present everywhere the humanity stands, and people are arguing on who is the
actor, on how and why the energy (or oil) production and distribution are controlled.
Globally, there is an increasing energy demand and a global concern on occurring
climate change, as well as a worldwide spread awareness of the necessity of finding
15
1.Introduction
alternatives. With regard to that, an emergent question is showing up: what consequence
would bring the development of a global energy based community and what if it is local
energy based. According to the previous discussion, it is important to remember that
global energy production can involve high energy losses due to the transportation itself
and risks of energy market monopoly or oligopoly. Local energy options seem to be
socially sustainable and economically viable, if proper infrastructures and services are
provided. Local energy development starts at a local scale, identifying the potential
alternatives to put into effect: in this regard, biofuels from agricultural crops often
represent a valuable opportunity. In relation to the local environmental and social
situations and to the pedoclimatic characteristics, many could be the suitable crops:
sugar crops (sugar cane, sugar beet, sweet sorghum), starchy crops (maize, wheat,
barley, rye, potatoes, cassava) and cellulosic material (switchgrass, Mischantus, willow,
poplar, crop stover) for the production of ethanol; oil crops (rapeseed, oil palm,
soybean, sunflower, peanut, Jatropha) for the production of biodiesel; biomass coming
from different crops but also from agro-industrial by-products and municipal wastes for
the production of biogas (FAO, 2008).
However, despite some possible negative impacts, many are the potential benefits of
bioenergy development. Indeed, it is clear the strong call for implementation strategies
that will act on the development of this sector. Often, well balanced policies and
accurate actions can strongly operate to maximize positive effects and reduce the
negative ones. As positive effects there are: diversification of agricultural output,
stimulation of rural development and contribution to poverty reduction, increase in food
prices and higher income for farmers, development of infrastructure and employment in
rural areas, lower greenhouse gas emissions, increased investment in land rehabilitation,
new revenues generated from the use of wood and agricultural residues, and from
carbon credits, reduction in energy dependence and diversification of domestic energy
supply, especially in rural areas, access to affordable and clean energy for small and
medium-sized rural enterprises. On the other hand, potential negative effects are
addressed to as reduced local food availability if energy crop plantations replace
16
1.Introduction
subsistence farmland and increased food prices for consumers. Demand for land for
energy crops may increase deforestation, reduce biodiversity and increase GHG
emissions. Increased number of pollutants, modification to requirements for vehicles
and fuel infrastructure, higher fuel production costs, increased wood removals leading
to degradation of forest ecosystems, displacement of small farmers and concentration of
land tenure and incomes, reduced soil quality and fertility from intensive cultivation of
bioenergy crops, distortion of subsidies on other sectors and creation of inequities
across countries represent some other alarming impacts (FAO, 2008).
A strong focus on this issue is necessary and more importance should be given to the
problems of biofuels’ production, by looking at them from an agricultural point of view.
To what concerns the fuels coming from food crops, the main problems seem to be the
competition for their destination as human food or animal feedstock and from the
competition for agricultural land resources, water, energy and nutrients. The fear
coming from the cultivation of food crops for energy production is also due to the
mismanagement of these crops. In fact, while climate change mitigation can be partly
achieved (if it is truly proved for some produce, for others should be cautiously
explored), mismanagement can lead to a loss of biodiversity, especially in the case of
repeated monoculture over the years, and in a reduced efficiency of water and soil
resources that are of vital importance. That is especially the case at the moment in non-
industrialized countries, where the demand for large area to place bioenergy plantations
is increasing (Wood, 2005; von Braun and Meinzen-Dick, 2009; Daey Ouwens et al.,
2007). The other option, represented by the use of “second-generation” biofuels, seems
to be of difficult and slow spreading in most countries at the present day, due to the lack
in technology knowledge and resources for processing the lignin component that is still
under development (FAO, 2008). What should not be forgotten is that second generation
biofuels might not affect the availability of food but they do compete for land, water,
nutrients and energy.
Thence, biofuels represent a valuable solution to mitigate global warming and to reduce
oil dependence. Nevertheless, significant objections are still heard against their use, as
17
1.Introduction
their consequences on communities could be positive as well as negative. Major
concerns lie in the selection of the fuel crop and its management in the cultivation and
processing steps: solutions may vary according to the regional context. Moreover, the
use of some fuel crops is controversial, as they have been proven to be not enough
efficient or useful. For some others, more research is required and their use as an energy
feedstock will heavily depend on how this research is carried out and how the results are
presented. Among these last mentioned, a relatively new energy crop is Jatropha curcas
L. (Figures 1.1 and 1.2).
1.2 Jatropha curcas L., a potential bioenergy crop
Jatropha curcas L. is a deciduous monoecious perennial shrub or small tree belonging
to the botanical family of Euphorbiaceae, to the tribe Jatropheae of the subfamily
Crotonoideae. Common name varies according to the region: in English it is called
'physic nut', while in Italian it is known as 'ricino d'inferno'. J. curcas probably
originated in southern Mexico or neighbouring parts of Central America, which are the
only areas where it has often been collected from undisturbed vegetations. It was then
distributed all over the world by Portuguese seafarers in the XVII century and is now
18
Figure 1.1. Jatropha curcas L. plantation atfruiting stage, in Maya Ranch, Belize, July22nd, 2009.
Figure 1.2. Jatropha curcas L. fruits, in MayaRanch, Belize, July 22nd, 2009.
1.Introduction
naturalized throughout the tropics and subtropics (Figure 1.3). Different parts of J.
curcas are used for a range of medicinal purposes; moreover it is a source of oil used for
soap production and as a source of energy, as mentioned before; it is also an important
hedge plant (Baldrati, 1950; Henning, 2007). Hereunder, a review of jatropha plants,
fruits, seeds and leaves (Figures 1.4, 1.5, 1.6 and 1.7).
19
Figure 1.4. Row of six years old Jatrophacurcas L. plants pruned at four years, inMaya Ranch, Belize, July 22nd, 2009.
Figure 1.5. Jatropha curcas L. dry fruit coatsand seeds. In the background, Arachispintoii growing as intercrop with jatropha, inMaya Ranch, Belize, July 22nd, 2009.
Figure 1.3. 'Global indication of the most suitable climate conditions for the growth ofJatropha (J. curcas L.) (30°N, 35°S) and Oil palm (Elaeis guineensis Jacq.) (4°N, 8°S)'.Source: Claims and Facts on Jatropha curcas L., Jongschaap et al., 2007.
1.Introduction
The plant ecophysiology and the botanical features have been investigated. The plant
develops a deep taproot and initially four shallow lateral roots (Figure 1.8). The stem,
arising from a thick, perennial rootstock, with watery to whitish latex, has a bark
smooth, grey or reddish, shiny, peeling off in papery scales. Leaves are alternate,
simple, petioled and glabrous, with a blade broadly ovate in outline, usually shallowly
5-lobed and margins usually entire. Terminal inflorescences contain unisexual flowers.
The fruit is a broadly ellipsoid capsule, smooth-skinned containing three ellipsoid seeds,
1-2 cm long, mottled black and coarsely pitted. Growth in J. curcas is intermittent and
sympodial, dormancy is induced by fluctuations in rainfall, temperature and light but
not all plants respond simultaneously. Pollination seems to be carried out by honeybees
and beetles (Bhattacharaya et al., 2005) and moths (Henning, 2007). In flowering, the
female flowers open one or two days before the males one; male flowers last only one
day. Seed never sets in indoor cultivation unless the flowers are pollinated by hand. J.
curcas occurs in semi-arid tropical and warm subtropical climates with mean
pedoclimatic surviving requirements as the followings: daily temperatures of 20-30°C,
annual rainfall of 300-600mm (but resistant to periods of drought of up to seven
months), absence of frost (Figure 1.9).
20
Figure 1.7. Six years old fruiting Jatrophacurcas L. plants, in Maya Ranch, Belize, July22nd, 2009.
Figure 1.6. One year old Jatropha curcas L.plant, in Warrie Head, Belize, July 22nd,2009.
1.Introduction
The main inputs for the production of oil-bearing fruits of J. curcas are land area
including the prevalent site characteristics, plantation establishment practices and
plantation management practices. The outputs are the seeds and other biomass elements
(Achten et al., 2008). J. curcas can grow in a wide range of soils: on degraded, sandy or
gravelly and even saline soil with low nutrient content. Nevertheless, clay soils are
unsuitable for the plant if water logging or saturation occurs due to the climatic
conditions. It is clear that J. curcas responds highly when growing on well aerated soils.
Sandy to loamy soils seem to be a best fit. Optimal pH reaction is considered between 6
and 8.5. The plant is well adapted to marginal soils with low nutrient content but in
order to support a high biomass production the crop shows a high demand for nitrogen
and phosphorus fertilization (Henning, 2007; Daey Ouwens et al., 2007). Among soil
proprieties, pH, EC, CaCO3, organic C and clay significantly affect the availability of
nutrients, thus soil conditions reflect the effect of jatropha cultivation practices on a
degraded soil. From the perspective of both soil structure and carbon and nitrogen
sequestration, jatropha cultivation under minimal soil disturbance can serve
‘environmental functions’. In fact, jatropha cultivation improves soil resistance to wind
erosion and enhanced macro-aggregate stability to water erosion. Under jatropha,
increased potential carbon sequestration rates are possible as stable micro-aggregates
21
Figure 1.9. Six years old Jatropha curcas L.plantation after an extraordinary dry month,in Maya Ranch, October 28th, 2009.
Figure 1.8. Particular of Jatropha curcas L.root system. Central taproot and four lateralroots are evident, in Belmopan, Belize,November 27th, 2009.
1.Introduction
can offer protection to organic carbon. Therefore jatropha cultivation programmes will
not only serve as a source of income-generation to resource-poor farmers but will also
improve the quality of their soils in the long run (Ogunwole et al., 2008).
Propagation is done by seeds or cuttings. Plants raised from seed are more resistant to
drought than those raised from cuttings, because of the taproot they develop. The
development of root system is then different, according to the originating part of the
plant (Achten et al., 2007). The taproot enables a straighter and deeper root system
growth so to extract moisture from deeper layers of the soil. This root structure is also
preferable in intercropping systems to minimize the competition for water and nutrients
between the different crops. Thereafter, nursery-grown seedlings have a higher survival
rate than direct-seeded ones and produce seeds earlier (Figure 1.10). Seeds in nursery or
direct seeding with seed treatment is recommended (Daey Ouwens et al., 2007). Seed
soaking in cold water for 24 hours is suggested for better and quick germination
(Kaushik et al., 2007), although it might influence more the germination celerity than its
rate (Sengfelder, personal comm.). At the onset of the rains the seedlings can be planted
in the field (Heller, 1996). It was noted that spacing of plants is a trade off between
biomass and fruit production. Thus, optimum spacing is differently achieved depending
on weather situation, site characteristic and intended objective (Achten et al., 2008).
Irrigation will depend on the climatic conditions of the location. Although J. curcas
can survive precipitation as low as 300mm by shedding its leaves, it does not produce
well under such conditions. Minimum and optimal rainfalls to produce fruits are
assessed on values of 600mm ha-1 y-1 and 1000-1500mm ha-1 y-1. Water and rains after
periods of drought will induce blossoming. Hence, too much rain and humidity will
provoke fungus, thus high rainfall might require other spacing (Daey Ouwens et al.,
2007). Indeed, an economic sustainable oil production is achieved with higher minimum
requirements of water of at least 750 mm annual rainfall or supplementary irrigation
(Henning, 2007). Plantations aiming at oil production might also need artificial or
organic fertilization. Fertilizers at least compensate the nutrient removal due to harvest
or management practice (e.g. pruning). Simultaneous reclamation of barren lands and
22
1.Introduction
biodiesel production will inevitably imply use of fertilizer and irrigation (Achten et al.,
2008).
Pruning is a very important issue as it determines to a large extent, although not
completely, seed yield in each site and it can facilitate manual and mechanical
harvesting of fruits (Figure 1.11). Canopy size determines the maximum number of
flowering branches. Large trees on a low planting density or smaller plants on high
densities can apparently both result in sufficient flowering branches (Daey Ouwens,
2007). The pruning should be done when the tree sheds leaves and enters a period of
dormancy (Kaushik et al., 2007), that is usually coinciding with the dry season. Cultural
practices in new plantations, thence, include regular weeding, pruning and fertilization.
Standard management count on a plant density field design of 1350-2500 plants ha-1
(Henning, 2007).
Diseases and pests attacks should not be underestimated. Opinions on this issue are
contrasting. In fact, Henning (2007) says that intervention against pests and diseases
occurs rarely and just in the case of powdery mildew (Uncinula necator), Alternaria
spp., and caterpillars of Spodoptera litura and several species of phytophagous beetles,
and particular attention must be put on intercrops grown together with J. curcas, as it
23
Figure 1.11. Six years old Jatropha curcas L.plant pruned two years before, in MayaRanch, Belize, July 22nd, 2009.
Figure 1.10. Jatropha curcas L. seedlings aweek after sowing, in Bullet Tree, Belize,September 30th, 2009.
1.Introduction
can be an alternative host (e.g. Cassava mosaic virus). While Daey Ouwens et al. (2007)
say that the plant is vulnerable to most common pests and diseases found in food crops,
adding that most of these pests and diseases can be treated fairly easily and, if required,
biologically.
Basic agricultural operations are done manually, and so harvesting and separation of
seeds from fruits. Handling after harvesting foresees a careful exsiccation in the shade
until 6-9% moisture content. Subsequently the extraction of the oil can be done
following different techniques (Henning, 2007). The reported yields range from
extremely low to high; Jongschaap et al. (2007) conclude to a potential yield range of
1.5-7.8 dry seed ha-1 y-1. As mentioned above, yield depends on site characteristics
(temperature, radiation, rainfall, soil type and soil fertility), genetics (a strict selection of
seeds or cuttings leads to more uniformity in offspring and higher yields per plant),
plant age and management (propagation method, spacing, pruning, fertilizing, irrigation,
etc.) (Daey Ouwens et al., 2007; Achten et al., 2008).
The oil contained in the seeds, around 35% by weight (Baldrati, 1950; Kandpal and
Madan, 1995; Ginwal et al., 2004; Jongschaap et al., 2007), has to be expelled or
extracted. For extraction of the jatropha oil two main methods have been identified:
mechanical extraction (with manual ram press or engine driven screw press) and
chemical extraction (aqueous enzymatic or solvent oil extraction). Finally the oil may
be refined in a continuous transesterification reactor to produce biofuel or diesel oil and
glycerol as a valuable by-product. The oil quality is dependent on the interaction of
environment and genetics (Jongschaap and van Loo, 2009; Achten et al., 2008). Thus,
the cake attributes change in relation to the oil characteristics and the oil extraction
method used. Anyway, the cake contains high-quality proteins and various toxins. The
presence of biodegradable toxins makes the fertilizing cake simultaneously serving as
biopesticide/insecticide and molluscicide. Anyway, it is advisable to check the absence
of phorbol esters in the crops grown on jatropha cake fertilized land, certainly in crops
for human consumption. Digesting the cake and bringing the effluent back to the field is
thought to be the best practice at present from an environmental point of view. Due to
24
1.Introduction
the toxicity of the seeds and oils, some attention should be paid to the human health and
work environment impact categories (Achten et al., 2008).
Available genetic resources show several types of J. curcas. Low-toxic type from
Mexico, type with larger leaves and larger but fewer fruits and seeds from Nicaragua,
male sterile type which produce more fruits than normal types, just to quote some
examples. A study on 200 J. curcas accessions from different regions around the world
highlighted, among other characteristics, the differences in oil composition that could be
regionally identified (Jongschaap and van Loo, 2009). In order to start breeding the
genetic variation needs to be assessed. Most plant material used so far is derived from
simple selection within semi-wild populations or landraces. Between-plant variation of
vigour and seed yield are tremendous and great genetic improvement in seed yields and
other important characteristics may, therefore, be expected from systematic breeding
(Figure 1.12). Obviously, oil yield per hectare will dominate breeding objectives for J.
curcas cultivars for biofuel production. Cultivars with compact growth would facilitate
harvesting (Henning, 2007). Literature reports lack of genetic variation. To date, it is
assessed a high phenotypic variation (e.g. plant architecture) in material from Latin
America (Figure 1.13). Genetic variability was found low in African and Indian J.
curcas accessions but high in Guatemalan and other Latin American ones. Diversity in
J. curcas should be found in wild species, in their centre of origin in Mexico, Central
and South America (Jongschaap and van Loo, 2009; Montes et al., 2008). Plant
breeding programmes should be carried out after a more through analysis of the existing
genetic resources and variability, that would allow getting the characteristics that would
be required. Among the most important and urgent features to be investigated, there are:
toxicity of seeds, oil-seed and seedcake (source of protein that could be suitable for
animal feedstock); drought resistance and water requirements under different
pedoclimatic situations; plant susceptibility to pests and diseases.
25
1.Introduction
Concerning environmental impacts of J. curcas production system, the main issues are
the energy balance, impact on global warming potential and land use impact. Energy
balance of J. curcas biodiesel is reported to be positive and the total energy inputs into
the crop to the energy output ratio is estimated at 1:4-5 (Henning, 2007). The available
information shows that energy balance improvement options lay in the cultivation,
where irrigation and fertilization are the most energy intensive practices, and
transesterification steps. How positive the balance is in reality, will mainly depend on
how efficiently the by-products of the system are used. Impact on global warming
potential showed a reduction of GHG emissions for the production of biodiesel from J.
curcas in comparison to fossil fuels. However, the removal of (semi-) natural forest for
the introduction of J. curcas is expected to have a significant negative effect on the
GHG balance of the whole life cycle. Ultimately, it is expected that land occupation
impact of J. curcas on the soil will be positive, as the plant is observed to improve soil
structure, is strongly believed to control and prevent soil erosion and sequestrates
carbon. Nonetheless, being an exotic species in most actual growing areas, the impact of
land use change towards J. curcas on biodiversity is expected to be negative, although
this will largely depend on the mix of land use which is replaced by J. curcas and on
how the plant is cultivated (Achten et al., 2008).
J. curcas’ considerable potential as an oil crop for biofuel purposes at relatively low
26
Figure 1.13. Particular of stem and lateralbranches of a year old Jatropha curcas L.plant, in Warrie Head, July 22nd, 2009.
Figure 1.12. Seed coats and kernels of threeaccessions of Jatropha curcas L., inBelmopan, Belize, November 2nd, 2009.
1.Introduction
costs and modest demands on the local agro-ecosystem has received much attention in
recent years. It is foreseen that within the next decade or so, J. curcas will become a
major source of renewable energy in the drier rural areas of (sub) tropical Asia, Africa
and America (Henning, 2007). The promise of J. curcas as a species to produce high
quantity and quality feedstock for bioenergy is considerable. First, yields are expected
to increase over the years as seed improvement takes effect; they are expected to reach 6
to 7 ton dry seeds ha-1 y-1 within few years, but only under optimal climate conditions,
using high yielding strains, and optimal soil fertility conditions. Looking at such
promise, it is concluded that jatropha might be an alternative for other oil producing
plants such as oil palm, especially for less humid areas (Daey Ouwens, 2007).
The role of J. curcas in bioenergy generation looks like to be of great interest; in fact,
biodiesel production from jatropha seeds give an optimistic impression of the capability
to combine the low-technology inputs required for oil production with other agricultural
interesting claims on the plant. In fact, many are the claims regarding J. curcas, and its
development as an agricultural crop appears to have many positive effects. The present-
day hype for this plant comes from the theoretical combination of all the good features
that characterize J. curcas cultivation, however they are not always scientifically proven
and barely come out altogether simultaneously in the same site. In fact, many good
characteristics of this plant appear to exist because of its rusticity and an intensive
exploitation it is not like to be supported by scientifically sound agronomic data. Indeed,
often good resistance characteristics are not linked with high productivity values
(Jongschaap et al., 2007). To understand better the limits and the potentials that J.
curcas crop growth may result from a more intensive and focused farming, the main
agronomic characteristics, the physiological behaviours, the reactions to different sites
and the relevance of genotype or environmental influences should be known, and if not,
they should be meticulously detected and, afterwards, explained to farmers. Keeping
this assessment in mind and looking at an objective of J. curcas cultivation techniques
improvement, knowledge gaps on botanical features, potential utilizations, claims and
facts regarding J. curcas and its production system will be hereunder briefly described
27
1.Introduction
and explained. In any case, a clear statement can be extrapolated: the plant cannot
perform all its functions together at the best level.
1.2.1 Knowledge gaps in Jatropha curcas L. research
Despite the huge interest that J. curcas production system has attracted by now, a lack
of knowledge and available data is evident. The main gaps concern some basic
agronomic characteristics, the application of the good agricultural practices, the
development of a complete J. curcas production system (including oil yield
characteristics and oil processing) and the input/output balances at all these stages.
Moreover, information is still required to assess the nutrient requirements and the dry
matter assignment in different agricultural settings and pedoclimatic conditions. There is
lack of data also in reported genetic variability that would allow beginning plant
breeding programmes. Further research towards the discovery of the potential of
utilization of other J. curcas products and by-products would be very welcome.
Accurate data on yield and on its characteristics are missing. In order to respond to the
J. curcas oil production want of a list of countries, in which incredible large areas, that
are drastically increasing, are planned to be grown with this plant, reliable information
on crop requirements and climate/soil characteristics are still very much required (Daey
Ouwens et al., 2007). Much agronomic and breeding work needs still to be done to
maximize oil production potential per ha and thus improve the economic sustainability
of jatropha oil production. To this, rapid multiplication techniques and facilities have to
be developed to make improved planting material available in adequate amounts. This is
especially urgent as planting of unimproved material not only leads to low returns on
investments but may also lead to a loss of interest in this crop (Henning, 2007).
Concerning the plant cultivation, substantial efforts should be made to streamline
observations in current jatropha planting sites, to implement specific experiments for
unravelling the impact of different production factors on crop performance and to
exchange knowledge and information, in order to prevent unjustified investments. It is
recognized that the main knowledge gaps are situated in the cultivation step, where a
28
1.Introduction
description of the best practice and the potential environmental risks or benefits are
needed. In fact, basic agronomic proprieties are not exhaustively understood and the
environmental effects have not been investigated yet (Achten et al., 2008). Correct
spacing should be identified depending on different intended objectives and much has
still to be learned from plant manipulation, from more or less intensive pruning or
curving of branches, at different moments. As a new technology, the micropropagation
is being developed by Manurung (Daey Ouwens et al., 2007; Achten et al., 2008).
Taproot potential has not been investigated scientifically. The susceptibility of J. curcas
to pests and diseases is a source of discussion and is believed to depend on the
management intensity. More experiments are needed where the growth effect on
different kinds of crops are monitored in intercropping systems. Impacts on soil
structure, water-holding capacity, soil decomposition, organic matter content and soil
biological activity should be brought under detailed investigation as well. Dominant
role of environment over genetics in seed size, seed weight and oil content (Achten et
al., 2008) should be more deeply investigated. Much research is still necessary to
improve yield, to exactly understand the energy efficiency of the plant under different
conditions, to allow use of bioproducts such as oil cake as animal fodder (Daey Ouwens
et al., 2007).
Nutrient requirements for maximum oil production are not well-defined for J. curcas
(Henning, 2007). No information is available on nutrient cycles and the impact on soil
biological life (Achten et al., 2008). The relation between plant nutrients, organic matter
content of the soil and micronutrients and yields is not fully understood (Daey Ouwens
et al., 2007). Jatropha has not been domesticated yet and basic knowledge of its soil-
plant relations is required for the development of appropriate agricultural techniques.
Very little is known about foliar nutrient content of jatropha and soil-plant relationship,
which is essential to domesticate the plant and establish the nutrients requirements
(Chaudhary et al., 2008).
The input levels to optimize the harvest index (HI) in given conditions are yet to be
quantified. Very limited information is available regarding acidification, eutrophication,
29
1.Introduction
and other LCA impact categories of the J. curcas production cycle. Increased
investigation of the cultivation step in the production of jatropha biodiesel will enable
researchers to assess the specific contribution of the plant in these impact categories as
well. As the reduction of global warming potential is one of the main aims of the J.
curcas biodiesel system, this confirms the research need on input-responsiveness of the
J. curcas cultivation step.
Good documented yield data are still scarce. Seed yield and biomass production in
different environmental and abiotic settings, varying provenances or accessions and
applying different levels of different inputs should be monitored in order to discover the
input-responsiveness of the plant in different settings as well as the interactions between
the different inputs and the interaction between the environmental and genetic set-ups
and the inputs. Notwithstanding, there is still insufficient information to account the
nutrient and water needs for specific environmental and genetic set-ups. The actual
potential of J. curcas cultivation should be explored, as it is not clear if the plant is able
to produce ecologically and socio-economically viable amounts of energy in barren
situation (Achten et al., 2008). From selection of basic plant material up to yield, there
are many options, with a lot of variation in available data and not enough information
for optimization. More research should also be initiated on medicinal proprieties of
different parts of the plant, e.g. wound healing, antimalarial and anti-HIV effects, and
investigation of the agronomic and medicinal potential of other Jatropha species would
be valuable as well (Henning, 2007).
J. curcas is still a wild plant with a wide variation in growth, production and quality
characteristics. In order to start breeding towards high yielding biodiesel plantations, the
best suitable germplasm has to be identified for different cultivation situations
(Henning, 2007; Daey Ouwens et al., 2007; Achten et al., 2008). For this reason,
research makes progresses thank to new patent free molecular marker technology :
conserved sequence based on NBS-gene family. A starting point in this sense could
reasonably be intercrossing ‘elite’ J. curcas accessions (e.g. ‘Cabo verde’) with low
toxic and toxic accessions as starting point for breeding, now that genetic analysis of
30
1.Introduction
segregating population is possible (Montes et al., 2008). More research is necessary on
oil content, oil quality/acidic composition and the influence of environment and genetics
on it. Vegetable oil can be used as base for liquid engine fuel in various ways; choice of
extraction method is clearly dependent on the intended scale of activity; crucial research
and development options lay in the maximization of the transesterification efficiency at
minimal cost. About this, an important issue is the improvement in the catalytic process,
certainly the recovery and the reuse of the catalyst. As part of the option of
decentralized processing units, low-cost, robust and versatile small-scale oil
transesterification designs should be developed (Achten et al., 2008).
1.2.2 Selection of knowledge gaps and justificationThe above mentioned statements and knowledge gaps lead the interest and the
requirement of further research that is now the case. A broad investigation appears to be
necessarily addressed to all the mentioned topics; however the evident risk of being
imprecise would necessary bring to a selection. As, to date, some major knowledge gaps
of the whole J. curcas production system are in the cultivation step, a deep analysis into
that will put in evidence the need of looking for growth variables in monoculture,
intercropping and hedges, as well as looking for sustainability indicators, also in these
three production systems.
Growth Parameters are of major concern to understand net primary production of the
plant, its potential and actual energy and water use efficiencies, its nutrient
requirements. In general, growth parameters are needed to better understand the
ecophysiology of the plant so to allow a full implementation of its potentials, adding the
required inputs. Concerning J. curcas growth parameters, a general overview will be
given. Firstly, a description is presented of growth parameters by plant parts: seed, root,
stem/wood, leaf, flower, fruit and whole plant (Annex 1a). In this section some of the
reported data are followed by annotations that would explain whether there were
exceptional conditions when the data were recorded. That is the case of seed
germination, oil quality, apical dominance and fitness. In fact, seed germination varies
31
1.Introduction
apparently depending on different pre-treatments; oil quality, that is its physical-
chemical proprieties and its constituent composition, varies under environmental
conditions and genotype (Jongschaap and van Loo, 2009; Achten et al., 2008). To what
concern apical dominance and plant fitness, it must be said that plant breeding is still in
its infancy. Variability in plant architecture between different accessions is reported
(Montes, 2008). Then, growth parameters are intended under different farming
condition. Three cropping systems are taken into account: monoculture, intercropping
and living fence. Same growth parameters in the three cases are reported and differences
between values will highlight differences between farming systems (Annex 1b).
The potential of jatropha oil production at a small scale and its implementation as a tool
for rural development lead to a necessary investigation of sustainability indicators. A
sustainability indicator is a parameter that allows understanding the impact of an action
at different levels, mainly environmental, economic and social. This indicator should be
clear enough to describe accurately the input/output ratio of each step of an entire
process and tell whether it is more or less sustainable. In the case of the J. curcas
production system, sustainability indicators will be identified and, firstly, divided into
agronomic, environmental, economic and social spheres (Annex 1c). These categories
were chosen to better explain the interactions between J. curcas production system
internal and external factors and actors. Then, an overview of sustainability indicators
will be given for different cropping systems: monoculture, intercropping and living
fence (Annex 1d), as above considered. A deeper investigation in this sense will allow
to define which one of the production systems is expected to be more sustainable. Here
a right and proper specification: often the results depend on local or regional variables
that are unable to be chosen or modified.
A relief of basic parameters coming out from the analysis of growth variables and
sustainability indicators and an attempt to link them together should eventually give a
general idea of growing patterns and impacts of the different J. curcas production
systems.
32
1.Introduction
1.3 Aim and objectives of the thesis
J. curcas production system is attracting worldwide Institutions, Companies and
Organizations attention, both for its oil yield suitable for biodiesel uses and for its
capability to sustainably interact with rural tropical and sub-tropical world. A lot of
projects are now taking place in Countries all over the world to assess the feasibility of
the set-up of J. curcas production systems and their implementation at different scales
and in relation with different realities and conditions.
The present work is a part of a wider research promoted by the 1st Coordinated Call for
a Transnational Research Activity under the ERA ARD net (the Agricultural Research
for Development; Dimension of the European Research Area): “Bioenergy – an
opportunity or threat to the rural poor”. Specifically, a joint consortium of academic,
governmental and private institutions has proposed the interdisciplinary research and
capacity development project “Bioenergy in Africa and Central America – Opportunities
and Threats of Jatropha and Related Crops”, thus selecting two main foci: a crop, the
Jatropha curcas L., and the regions, Central America and East Africa. The objective of
ERA-ARD is to follow the growth and development of Jatropha curcas by monitoring
important dynamic crop variables in different production systems and densities, and
relate them to the environmental circumstances. The opportunity that I have to join this
ERA ARD proposal has included a research on crop growth and processing at Tropical
Studies and Development Foundation, in Belmopan, Belize, under the scientific
guidance of Plant Research International, Wageningen, the Netherlands.
The main research activity was held in Belize and consisted on gathering crop growth
and development data from existing plantations (LAI, yield) and to set up a field trial, in
view of establishing the growth and development of Jatropha curcas L., and searching
the links between these data to the environmental variables. The aim to share knowledge
and to set up discussions on biofuels at national and regional levels is also pursued. In
Belize, the goodness of jatropha as an oil feedstock and as a tool for rural development
at small and medium farm size will be evidenced by further research, looking at the
results in the coming years.
33
2. Materials and Methods
The work was structured and developed in two periods. The first period, from 14th April
to 14th May 2009, was spent at Plant Research International (PRI) of the Wageningen
University and Research centre, the Netherlands, and was directed to the bibliographic
research and study of the state of the art on the jatropha plant and the whole jatropha
system, with a focus on the cultivation. Research activities have also been undertaken in
the greenhouse, such as for leaf area index (LAI) and light interception measurements,
and in the laboratory, such as for oil extraction. The second period, from 15th July to 15th
December, was dedicated to the field research in Belmopan, Belize, at the NGO
Tropical Studies and Development Foundation (TSDF), with the collaboration of Galen
University – Applied Research and Development for Sustainability Institute (GUARD)
and the University of Belize (UB).
2.1 Research at PRI Wageningen, the Netherlands
During the research period in Wageningen twenty-six jatropha plants from four different
accessions from Central America coded as 160 (7 plants), 176 (9 plants), 177 (7 plants)
and 184 (4 plants) were grown in a greenhouse experiment for leaf area (LA)
measurements and for assessing the interception capacity of photosynthetically active
radiation (PAR). The plants were five months old, they were daily watered in the
morning and evening and exposed to 12 hours of light, from 7.00 to 19.00 hours. For
each plant, cotyledons and leaves were counted, and length (L) and width (W) of each
leaf was measured; then leaf area was calculated according to the following formula:
A=0.84∗L∗W 0.99
(Liv Soares et al., 2007). Jatropha light interception was also measured through a beam
('SunScan Canopy Analysis System, type p.SS1'), which could measure the fraction of
photosynthetically active radiation (PAR) intercepted by the plants at different levels in
the canopy (top, middle and bottom) and in fifteen different plant densities (Table 2.1).
This research phase allowed testing a methodology for LA estimation on field and light
interception calculations that were later used for the research activities in Belize.
Part of the research activity was carried out in the chemical laboratory, where oil was
2.Materials and Methods
extracted from jatropha seeds and weighed. Kernels were separated from shells,
smashed and mixed with the solvent: 7.5ml of hexane per round of extraction (3 times)
with about 0.4g to 1.0g of kernel (van Loo, 2009, personal comm.).
2.2 On field research in Belize, Central America
Belize, Central America, has a total land area of 22.966 km2. The Country is located at
17°15' N, 88°45' W, with climate characterized by a dry and a rainy (June to November)
season and mean annual rainfall from 1524mm in the north to 4064mm in the south
(Figures 2.1 and 2.2) (CIA World Fact Book, 2009; Belize National Meteorological
Service, 2009). Central Region, where the trials of the present research are located,
shows a primary and secondary rainfall maxima occurring in June and September; in
this region, main soil type is cambisol (FAO et al., 2009). In the Country, jatropha is
known as physic nut and used for curative purposes; just recently it received more
attention by the Ministry of Agriculture and some private investors, although policies on
bioenergy and market for jatropha products are lacking.
36
Table 2.1. Fifteen J. curcas plant set-ups for LAIand light interception measurements(Jongschaap et al., unpublished data)
Treatment Length Width Area(m) (m) (m) (m) (m2)
1 1,00 0,90 3,00 4,50 13,502 1,00 0,60 3,00 3,00 9,003 1,00 0,45 3,00 2,25 6,754 1,00 0,30 3,00 1,50 4,505 0,90 0,90 2,70 4,50 12,156 0,90 0,60 2,70 3,00 8,107 0,90 0,45 2,70 2,25 6,088 0,90 0,30 2,70 1,50 4,05
9a 0,60 0,90 1,80 4,50 8,109b 0,60 0,60 1,80 3,00 5,4010 0,60 0,45 1,80 2,25 4,0511 0,60 0,30 1,80 1,50 2,7012 0,45 0,45 1,35 2,25 3,0413 0,45 0,30 1,35 1,50 2,0314 0,30 0,30 0,90 1,50 1,35
Row Distance
Plant Distance
2.Materials and Methods
Field trials were performed in three areas in Belize: at Maya Ranch, a six year old
jatropha plantation; at Warrie Head, a one year old jatropha plantation; at Central Farm,
a new plantation of jatropha, whose design was set up at Wageningen. These three trials
were treated and monitored trough the study of different variables: crop growth and
development was monitored through the Leaf Area Index (LAI) measurement (a non-
destructive method useful in yearly biomass production assessment) in all the three
trials, while yield was measured only at Maya Ranch. Measurements on seed dimension
and a germination test, other biomass production and crop development indicators, were
performed at Bullet tree, the nursery for the jatropha seedlings destined to Central Farm
trial. Environmental variables taken into consideration were: climatic data (the same for
the three trials) and soil samples (at Central Farm trial, only). Locations of
meteorological stations and experimental sites are shown in figure 2.3.
37
Figure 2.2. Map of Belize andits Districts (source:http://www.watersidebelize.com/images/belize_map.jpg).
2.Materials and Methods
38
Figure 2.3. Map of Belize and location of meteorological stations (PhilipGoldson International Airport and Central Farm) and experimental sites(Maya Ranch, Warrie Head, Bullet Tree and Central Farm).(Source: http://www.hydromet.gov.bz/AgroClimat_Stations.htm).
2.Materials and Methods
2.2.1 Climate data
Climate data collection was a kind concession from the Belize National Meteorological
service (www.hydromet.gov.bz). Weather variables were recorded on a daily basis
(Table 2.2), through two climate stations: one station was settled at Philip Goldson
International Airport (17°32' N, 88°18' W) and recorded radiation (kJ m-2 d-1), vapour
pressure (kPa) and wind speed (m s-1); the second one, in Central Farm (17°11' N,
89°00' W), recorded Min and Max temperatures (°C) and precipitation (mm d-1). Both
stations were selected as the closest available to trials and able to record the required
data on a daily basis. However, actual weather variables in the experimental sites might
slightly differ. In fact, trials occurred in different locations at around 100km to 140km
from Philip Goldson International Airport and 1km to 25km apart from Central Farm
weather stations (Figure 2.3).
Table 2.2. Weather variables required on a daily basis.
Abbreviation Weather variable Unit
Rad Radiation (kJ m-2 d-1)Tmax Maximum temperature (°C)Tmin Minimum temperature (°C)VP Vapour pressure (kPa)WS Wind speed (m s-1)P Precipitation (mm)
39
2.Materials and Methods
2.2.2 Maya Ranch trial
Maya Ranch field trial, with an area of almost 0.5ha, is located at the 4th mile on the
Caracol Road, in Cayo District, at an altitude of 150 meters above the sea level (Figures
2.4 and 2.5), in a location out of the main routes. The area is surrounded by tropical
rainforest and was formerly used as pasture for sheep, then abandoned. In June 2003,
TSDF transplanted around five hundred jatropha seedlings, from seeds harvested from
wild spontaneous and backyard grown isolated trees. Jatropha was planted in the
context of an Organization of American States (OAS) funded agro-forestry project, that
involved the planting of a teak plot (Tectona grandis) that still exist beside the jatropha
field, and the sowing of Habanero peppers (Capsicum sp.) and Arachis pintoii as
suitable inter-crops for jatropha. To date, A. pintoii is still growing on the south-east side
of the jatropha plantation and is giving positive feedback since it is a leguminous able to
control weed and its cultivation does not require much labour. A. pintoii, known in
Belize as Pinto peanut (English) and Maní forrajero (Spanish), is a perennial herb that
develops a strong taproot and forms a dense mat of stolons and rhizomes up to 20 cm
deep; there are low and highland species (up to 1400m) that show high tolerance to
shade and drought. It has been used as a forage legume in intensively managed
grass/legume pastures and tree plantations, or as a ground cover in tree plantations
(Cook, 1992). Its key benefits are weed control, nitrogen fixation and ability to lower
surface temperature for better soil health and moisture.
The project was temporarily suspended, in 2006/2007, and the whole area was left
abandoned, until July 2009, when the jatropha field became a trial to the purpose of the
current research for which an inventory was done, on 22nd July. The inventory lead to
the following results: 458 plants were counted, organized in 8 rows. The distances are
4m between rows and 2m between the plants within the row (1250 plants ha-1). The field
is oriented on a south-north axis and a slight slope gradient is present in this direction,
from the south side where the upper part is, to the north, at the bottom of the field
(lower part). In the field, three sets of jatropha plants were recognized: i) the plants of
the two west side rows and the last six or seven plants of each row at the bottom of the
40
2.Materials and Methods
field appeared smaller and less vigorous than the others, and they were barely bearing
fruits, as a result probably of less deep soils on this side and water logging at the bottom
of the field; ii) about one third of the plants towards the northern part had been pruned
in 2006/2007, they presented long and straight upward branches and already some
fruits; iii) the remaining two thirds consisted on the largest trees, with many branches
that closed completely the rows and were bearing a lot of fruits in groups of three to
eight racemes, A. pintoii was found growing below these plants. Two-meter high wild
herbaceous vegetation was growing along the field and in the surroundings, which have
been cut by machete twice during the growing season, in July and October 2009.
Beginning a research activity on a field at that stage required some quick decisions,
therefore two trials were initiated: they have been developed in separate times during
the growing season but both of them have been set up in the same field and considered
the same jatropha plantation. The first trial A (27th July – 10th August) focused on the
harvest, while the second trial B (1st September – 1st December) on LAI measurements,
as described below.
For the first trial A, 'pruning' and 'intercropping' were identified as already existing
treatments, and two plots were selected within the field: one with pruned plants growing
in monoculture (named 'pruned'), and, the other one with not-pruned plants under which
A. pintoii was vigorously growing (named 'not pruned')(see annex 2, table a). Fruits
41
Figure 2.5. Jatropha curcas L. plantation, inMaya Ranch, Belize, August 11th, 2009.
Figure 2.4. Jatropha curcas L. row inintercropping with Arachis pintoii, in MayaRanch, Belize, August 11th, 2009.
2.Materials and Methods
were harvested and dried separately by plot. The harvest was done on 7th July and 10th
August, 2009, and fruits were left drying under a roof during four to six weeks. After
this period, the fruits have been weighed on a 100g precise scale separately as follows:
7th July-pruned, 7th July-not pruned, 10th August-pruned and 10th August-not pruned.
From each of the four groups, a 2% fruit sample (between 140g and 740g) was picked
and coats and seeds were separated and weighed on a 1g precise scale. From each of the
four groups, a 100g seed sample was chosen and shells and kernels separated and
weighed on a 1g precise scale. Moreover, one thousands of randomly selected fruits
were opened: the number of seeds per fruit was counted and the average coat to seed
weight ratio was measured on a 1g precise scale. A 100 seed sample was crushed and
shell to kernel ratio was measured on a 1g precise scale.
For the second trial B, two already existing treatments were identified: pruning and
intercropping, and three plots were selected according to their cultural management, as
follows: 'intercrop/not pruned', 'monoculture/pruned' and 'monoculture/not pruned' (see
annex 2, table b). 'Pruning' referred to those plants that had been pruned two years
before at an height of 60cm, and, as intercrop, A. pintoii was maintained because its
easy-to-cultivate characteristics and its reciprocal benefits with J. curcas had been
noted. To record jatropha growth and development, 90 monitoring plants were selected
for LAI measurements: 36 plants from the 'intercrop/not pruned' plot, 18 from the
'monoculture/pruned' plot, 36 from the 'monoculture/not pruned' plot. LAI
measurements and estimation have been performed on 1st September, 1st November, 1st
December, according to the methodology described in table 2.3. The choice of different
amount of monitoring plants in the plots was necessarily taken as a trade off between
the existing situation and the new research objectives. Furthermore, on the 1st November
and the 1st December, the length and the effective length of representative branches of
the monitoring plants were measured to report the leaf production and fall off trends.
Effective branch is expressed as the segment of the branch in which green leaves are
still growing. This methodology allowed to monitor two aspects of plant growth and
development: first, to record the branch part actually involved in solar radiation
42
2.Materials and Methods
interception and to monitor how its length changes during the season; secondly, to
observe the plant dry matter production potential and its nutrients cycle, for what
concern leaf production and decay, from the soil deeper layers to the leaves back to the
soil, on the superficial layers.
Further calculations were made to find out intercepted solar radiation by the leaves of
the monitoring plants, applying the following formula:
1−e−k∗LAI
from Beer's Law formula for light interception, first described for plants by Monsi and
Saeki (1953), where k=0.68, in the case of J. curcas L. (Jongschaap, unpublished data).
Table 2.3. Estimation method of the Leaf area per tree. 1Estimation method per leaf presented at
Expert seminar on J. curcas L. (March 2007) (Jongschaap et al., 2007).
(example
data)
unit
Measure the length of a representative branch a 0.75 (m)
Count the number of leaves on this branch b 17 (#)
From the mid-section of the representative branch, select
a representative leaf. Measure the length from the point
where the leaf sheath is attached to the petiole to the
opposite point of the leaf
c 21.5 (cm)
Measure the maximum width of the leaf, perpendicular
on axis of the previous measurement
d 18.5 (cm)
Estimate how often this representative branch ‘fits’ in
the monitoring tree (e.g.5.5 similar branches)
e 5.5 (#)
Leaf Area1 = 0.0001 m2 cm-2 * b * 0.84 * (c * d)0.99 * e 3.50 (m2 tree-1)
43
2.Materials and Methods
2.2.3 Warrie Head trial
Warrie Head field trial, about 0.8ha large, is located just off the 9th mile of the Western
Highway, from Belmopan to San Antonio, in Cayo District, at an altitude of 45 meters
above the sea level (Figures 2.6 and 2.7). The area is a private property, surrounded by
forest, and at the border of the Belize River. In 2008 the land was cleared from the
prevalent graminaceae wild vegetation and ploughed. In July of the same year, in the
framework of an OAS-EEP research project, TSDF planted around five thousands
jatropha seedlings of two accessions (from Guatemala and Cuba, the Cuban being called
'Cabo Verde'), at two different spacings (3*1.7m alternated with 1.7*1.7m and 4*1m)
but resulting in the same plant density of 2500 plants ha-1. Water soluble polyacrylamide
(ultra-fine water-soluble polymer/acrylamide providing benefits as soil conditioning
agents) in one half and effective micro-organisms (a biological product that contains a
mixture of beneficial organisms, such as lactic acid bacteria, yeast, and phototrophic
bacteria) on the other half of the field were sprayed (Baumgart and Sengfelder, personal
comm.). On the short sides of the trial, additional jatropha seedlings were transplanted
and not sprayed with micro-organisms. An irrigation system was installed. In October
2008, almost two thirds of the jatropha plants were uprooted and died, as a consequence
of an extraordinary flood from the Belize River. The field was left abandoned until its
rehabilitation as a trial for the current research, in July 2009.
44
Figure 2.6. Jatropha curcas L. plantation andparticular of irrigation system (not in use), inWarrie Head, Belize, August 11th, 2009.
Figure 2.7. Jatropha curcas L. plantation(distance 1.7m between the two centralrows), in Warrie Head, Belize, August 11th,2009.
2.Materials and Methods
For this trial, the preparatory inventory lead to the following results and assumptions:
1476 plants were counted, the majority of them being the additional plants in the sides
of the EEP-OAS trial; these plants survived the flood because they were growing in a
slight hilly area; the treatments still existing after the flood were genotype and plant
spacing; at this point on time the micro-organisms previously sprayed are most likely
lost and not able to interfere in the plantation; concerning the plant size, a great
phenotype variability was evident (individual height from 0.3m to 3m), but plant
architecture appeared quite similar and suggested a strong competition for light with
wild herbaceous vegetation; apparently, soil is deep. During the trial, the field was
cleared by machete and bush-hogger twice, in July and in October 2009. As shown in
annex 2, table c, the field is organized in four groups, divided by genotype and plant
spacing in: Guatemala-(3*1.7)*1.7m2 (328 plants), Cuba-(3*1.7)*1.7m2 (370 plants),
Cuba-4*1m2 (387 plants) and Guatemala- 4*1m2 (391 plants), where (3*1.7)*1.7m2
spacing consists in the 'double row' and 4*1m2 is 'single row'. Both spatial design result
in 2500 plants ha-1. The research activity, then, started from this situation and focused on
LAI measurements. Each group was divided in three sub-plots and six monitoring plants
have been chosen from each sub-plots. In total, the same 72 plants (18 per group) were
selected for LAI measurements four times in the growing season on 2nd September, 2nd
October, 2nd November and 2nd December. The methodologies used for LAI
measurements and estimation and for effective branch length measurements are similar
to the ones applied for Maya Ranch trial, as well as the formula used to calculate
intercepted solar radiation.
2.2.4 Central Farm trial
The trial in Central Farm was established in the framework of the project 'ERA-ARD
Biofuels in Africa and Central America 2009-2013'. The preparatory work consisted on
the experimental design finalization and on the seed retrieval. The on field activities
have been carried out in two places: the sowing was done in a nursery at Bullet tree and,
two months after, the seedlings were transplanted on field at Central Farm.
45
2.Materials and Methods
The nursery was set up at Bullet tree, three miles off the west end of the Western
Highway, in Cayo District, at an altitude of 80 meters above the sea level (Figures 2.8
and 2.9). At the nursery stage data on seed dimension were taken, a germination test, LA
measurements and destructive biomass assessment were performed, from the seed to the
two month old seedlings. The nursery was located in a vegetable organic farm, and teak
seedlings were present, too. Once a week all the plants, including the jatropha, were
sprayed with a micro-organisms mixture that granted the sanity of the seedlings during
this raising period. For the purpose of the ERA-ARD project, three seed accessions have
been used: the Belize local one, collected in Maya Ranch, the Guatemalan G17
provided by the company 'Biocombustibles de Guatemala' and a low-toxic Mexican
provided by the 'Universidad Autónoma Chapingo'. The average 100-seed weight was
established weighing 937 Mexican seeds, 822 Guatemalan and 1000 Belizean on a 1g
precise scale. The length and the width of hundred seeds per accessions were measured,
and the length to width ratio was calculated. Hundred seeds per accession were crushed,
and shell and kernel were weighed separately. After these measurements, on the 23rd
September, 1144 seeds per accessions were sown in black cylindrical perforated plastic
bags, 20cm high and 10cm in diameter, filled with local soil and rice husks (Figure 2.8);
they were watered twice daily and sprayed with an EM mixture once a week. More
Belizean seeds were sown: 288 on the same day and 1088 on the 9th October, in the
context of the EEP project. Surveys at the nursery were done on the 30th September, 2nd
and 7th October, and on the 21st October for the last sown seeds: germinated seeds and
standing plants were counted. At the nursery stage, ten plants per accessions were
randomly selected and LA measurements were performed one month after the
germination (3rd November), and at the moment of transplanting (26th November,), using
the same methodology explained for Maya Ranch trial. On the 26th November, the same
ten plants per accessions were uprooted and dried under a roof for two weeks: on the
11th December dicotyledons, leaves, petioles, stems and roots were counted and weighed
on a 1g precise scale. All stems and some leaves of Guatemalan (11 leaves) and
Belizean (1 leaf) accessions were still green and fresh. Tap root lengths were measured.
46
2.Materials and Methods
On the 26th November, 1494 jatropha plants were transplanted on a 0.6ha field at UB
Campus, according to the design in annex 2, tables d and e. Additionally, 504 plants
were transplanted on the north side of the experimental plot (264 plants, 0.15ha) and on
the south (240 plants, 0.14ha) (see annex 2, table f). The field selected is located on the
top of a hilly area at Central Farm, in Cayo District, at an altitude of 60 meters above
the sea level (Figure 2.10). The field is east to west oriented and has a pig house on the
east side, a vegetable garden and the additional jatropha on the south, orange trees on
the west and the natural forest on the north, beyond the additional jatropha strip. There
is a slight slope gradient going downwards from south to north. Formerly, there was an
orange plantation, then, nearly half of the field was covered by meadow and half
cultivated with corn (on the east side). The field has been bush-hogged, cleared and
plough prior the transplanting. The transplanting followed the trial set up: a randomized
blocks design with three factors and three repetitions (see annex 2, table d). The factors
were three genotypes: Mexican, Guatemalan and Belizean; three agricultural production
systems: monoculture, intercropping with A. pintoii and living fence; two plant densities
of about 1250 and 2500 plants ha-1, organized in spacing of 3.7*2.2m2 and 3.7*1.1m2 in
the plot (monoculture and intercropping) and 0.25m and 0.5m in the living fence. There
were twelve treatments per block, repeated in three blocks, resulting in a total of 36 sub-
plots in the field. Moreover, six treatments repeated four times for a total of 24 segments
47
Figure 2.9. Jatropha curcas L. nursery, inBullet tree, November 2nd, 2009.
Figure 2.8. Sowing Jatropha curcas L.seeds, in Bullet Tree, Belize, September23rd, 2009.
2.Materials and Methods
in the living fence. In each of the thirty-six block, six monitoring plants (which had at
least 1 border row in the sub-plot) were selected and LAI measurement was performed,
on the 2nd December, using the same methodology explained for Maya Ranch trial
(Figure 2.11). For the statistical analysis, although, the design was reinterpreted, as, at
the time of the first LAI measurement, intercropping was not available and genotype
and plant density were the only factors. The trial was treated as a complete randomized
block design for the analysis of the variance, though not two repetitions per three blocks
have been considered but totally six repetitions for each treatment.
On the 10th December, after the transplanting of jatropha but before A. pintoii was in the
ground, representative soil samples were taken from each of the three blocks at 0-20cm,
20-50cm and 50-100cm depths. For the size of the experiment, six random pits per
block were prepared and samples from the three depths extracted with an auger. In total,
nine soil samples were collected for different soil characteristics (Table 2.4).
48
Figure 2.11. LAI measurements of Jatrophacurcas L. with technicians from the Ministryof Agriculture and the University of Belize,an example of knowledge sharing andinstitutional strengthening, in Central Farm,Belize, December 2nd, 2009.
Figure 2.10. Transplanted Jatropha curcasL. seedlings at 60 days, in Central Farm,Belize, November 26th, 2009.
2.Materials and Methods
Table 2.4. Soil variables required for 1st soil characterization.
Abbreviation Soil variable Unit
Sand% Sand (%)Silt% Silt (%)Clay% Clay (%)BD Bulk density (g cm-3)OM% Organic Matter content (%)C% Carbon content (%)Norg% Organic Nitrogen content (%)N Mineral nitrogen (ppm)P Available Phosphorous (ppm)K Potassium (ppm)
2.3 Statistical analysis
The collected data were analysed and organized in factorial spreadsheets, using
OpenOffice.org Calc. Average, standard deviation and standard error of the treatments
of each trial were calculated. Thereafter, descriptive methods have been used for climate
data, fruit yield at Maya Ranch, jatropha seed dimensions and germination rate in Bullet
Tree; while, on data collected at Maya Ranch (LAI and effective branch length), at
Warrie Head (LAI and effective branch length) and at Central Farm (LAI) the software
Anova97 ver. 3.12 (Onofri, 1997) was used to perform the analysis of the variance. In
each trial, monitoring plants were grouped and averaged by treatment and block (or
repetition), and the average of these groups were compared, to the purpose of the
ANOVA. To differentiate the means, the Duncan test with P=0.01 was applied in all the
cases, except where otherwise specified.
49
3. Results and discussions
Outcomes of the preparatory research in Wageningen and of the on field research in
Belize, for the period July – December 2009, are presented in this chapter.
3.1 Important drivers for Jatropha curcas L. growth and
development and how are these for Belize
Weather variables, soil composition and nutrients availability are main drivers that
contribute to characterize the pedoclimatic condition of an agro-ecological zone and
directly influence crop growth and development. In the current research it was possible
to gather climate data, provided by the Belize National and Meteorological Service. To
this purpose, the closest available climate stations were used: in Central Farm (1km to
25km apart from the experimental sites), to record temperature (Min and Max) and
precipitation, and at Philip Goldson International Airport (100km to 140km apart from
the experimental sites), to record radiation, vapour pressure and wind speed. With
regard to this, it should be reminded that this situation may have influenced some
findings of this research: in fact, it is possible that radiation, vapour pressure and wind
speed values recorded in a station by the coast of the Caribbean sea and close to a large
urban area (Belize City, 70000 inhabitants) may differ from actual values occurred more
than 100km in the inland in less populated areas. Hereunder, climatic situation in Belize
for the year 2009 is summarized on a daily basis.
3.1.1 Radiation and light interception
Over the whole year 2009, radiation showed the highest mean value in May, where it
reached more than 18kJ m-2 d-1; since then, mean monthly values were constantly and
gradually declining to 12kJ m-2 d-1 recorded in December (Figure 3.1).
To analyse resource use efficiency, solar radiation interception was measured. Light
interception formula for jatropha has been calculated in a trial at PRI Wageningen,
where measurements and calculations on jatropha at different plant densities indicate
that value of coefficient 'k' is 0.68. However, it changes according to different LAI: in
fact, for LAI>7, k=0.55 and for LAI<1-1.5, k=0.75 (Jongschaap, unpublished data).
3.Results and discussions
3.1.2 Temperature
Mean monthly temperatures have been recorded to be between 15 and 35°C, with
average Maximum temperature around 31°C and minimum around 21°C. Both Max and
Min temperature values were above the mean from April to October (Figure 3.2).
52
Figure 3.1. Mean monthly values of radiation recorded at Philip Goldson International Airportmeteorological station, in Belize, 2009. Source: Belize National Meteorological Service,personal communication.
J F M A M J J A S O N D
0
5
10
15
20
Weather variables, Belize, 2009Mean monthly values - Philip Goldson International Airport station
Radiation [kJ m -2 d-1]
Figure 3.2. Mean monthly values of minima (Temp. Min.) and maxima (Temp. Max.)temperatures recorded at Central farm meteorological station, in Belize, 2009. Source: BelizeNational Meteorological Service, personal comm.
J F M A M J J A S O N D
0
5
10
15
20
25
30
35
40
Weather variables, Belize, 2009Mean monthly values - Central Farm station
Temp. Max. [°C]
Temp. Min. [°C]
3.Results and discussions
3.1.3 Water
A total yearly precipitation of 1476mm was recorded in Central Farm, where the driest
period occurred from February to May, with about only one sixth of the yearly
precipitation (245.1mm); while the wettest months have been June, July, August and
November, totalling 792.2mm, equivalent to more than a half of total yearly
precipitation. Oddly, October was recorded to be exceptionally dry, being the driest
month with only 31.4mm of rainfall (Figure 3.3). Given this information, the beginning
of the growing season of jatropha could have been most likely established in June, when
important precipitations occurred on the 5th (72mm) and between 16th and 20th
(86.4mm).
3.1.4 Vapour pressure and wind speed
Vapour Pressure was at lowest levels of around 25kPa in the beginning of the year, then
increased from April, reaching maximum values between June and September when it
was recorded at around 32kPa; it finally came down to values close to 27-28kPa in the
last two months of the year (Figure 3.4).
53
Figure 3.3. Total monthly values of precipitation (Tot. Precip.), number of days of rain andmean monthly precipitation (Mean Precip.) recorded at Central Farm meteorological station, inBelize, 2009. Source: Belize National Meteorological Service, personal comm.
J F M A M J J A S O N D
0
50
100
150
200
250
300
Rainfall distribution, Belize, 2009Total monthly values - Central Farm station
Tot. Precip. [mm]
Days of rain [#]
Mean Precip. [mm]
3.Results and discussions
Wind speed mean values over the year were recorded to be around 3m s-1, with slightly
above-the-mean values from January to July and slightly below-the-mean in the rest of
the year (Figure 3.5).
54
Figure 3.4. Mean monthly values of vapour pressure (Vap.Press.) recorded at Philip GoldsonInternational Airport meteorological station, in Belize, 2009. Source: Belize NationalMeteorological Service, personal communication.
J F M A M J J A S O N D
0
5
10
15
20
25
30
35
Weather variables, Belize, 2009Mean monthly values - Philip Goldson International Airport station
Vap.Press. [kPa]
Figure 3.5. Mean monthly values of wind speed recorded at Philip Goldson InternationalAirport meteorological station, in Belize, 2009. Source: Belize National Meteorological Service,personal communication.
J F M A M J J A S O N D
0
1
2
3
4
5
Weather variables, Belize, 2009Mean monthly values - Philip Goldson International Airport station
Wind Speed [m s-1]
3.Results and discussions
3.2 Response of genetically different accessions to available
resources in Belize
Different accessions have been used in the three trials: local Belizean, in Maya Ranch,
and Cuban and Guatemalan, in Warrie Head, where plants were already in the ground;
while in Central Farm, seeds from Mexico, Guatemala and Belize were analysed and
sown. In this section, firstly, seed morphological characteristics, and, secondly,
responses to agro-ecological condition in Belize are reported. Results achieved in
Central Farm trial are treated in the frame of work package 1 'Crop growth and
processing' of the ERA-ARD project 'Bioenergy in Africa and Central America –
Opportunities and Threats of Jatropha and Related Crops'. Results obtained refer to seed
dimension, germination, LA, fresh seedling weight and taproot length, during the
nursery stage in Bullet Tree, and to LAI measurements during transplanting in Central
Farm.
3.2.1 Seed dimension and weight
Measurements of length, width and hundred seed weight of J. curcas L. were
determined for three genotypes: a low-toxic Mexican, a Guatemalan (G17), and a local
Belizean accession. Guatemalan seeds were recorded among the largest for dimensions,
(Figures 3.6, 3.7 and 3.8) and weight (Figure 3.9). Guatemalan average seed length was
above 1.8cm and had 100-seed weight of 73g. Mexican and Belizean seeds had an
average length slightly under 1.8cm and a 100-seed weight, well below Guatemalan
values, at 58g for Mexican seeds and 55g for Belizean seeds (Figure 3.10).
55
3.Results and discussions
56
Figure 3.6. Length of jatropha seeds as average of a hundred seed sample peraccession. Seed accessions are from Mexico (low-toxic), Guatemala (G17) andBelize (local). 2009.
1.35 1.45 1.55 1.65 1.75 1.85 1.95 2.05 2.15
0
10
20
30
40
50
Length of jatropha seeds of three accessions, Belize, 2009Bullet Tree, nursery
Mexico
Guatemala
Belize
Class central value [cm]
Fre
qu
ency
[# o
f se
eds
]
Figure 3.7. Width of jatropha seeds as average of a hundred seed sample peraccession. Seed accessions are from Mexico (low-toxic), Guatemala (G17) andBelize (local). 2009.
0.82 0.87 0.92 0.97 1.02 1.07 1.12 1.17 1.22
0
10
20
30
40
50
Width of jatropha seeds of three accessions, Belize, 2009Bullet Tree, nursery
Mexican
Guatemalan
Belizean
Class central value [cm]
Fre
qu
ency
[# o
f se
eds
]
3.Results and discussions
57
Figure 3.8. Length to width ratio of jatropha seeds as average of a hundred seedsample per accession. Seed accessions are from Mexico (low-toxic), Guatemala(G17) and Belize (local). 2009.
1.46 1.54 1.62 1.7 1.78 1.86 1.94 2.02 2.1
0
10
20
30
40
50
Length:width ratio of jatropha seeds of three accessions,Belize, 2009 - Bullet Tree, nursery
Mexico
Guatemala
Belize
Class central value
Fre
qu
ency
[# o
f se
eds
]
Figure 3.9. Weight of 100 seeds of J. curcas L. of accessions from Mexico (low-toxic), Guatemala (G17) and Belize (local). 2009.
Mexico Guatemala Belize
0
10
20
30
40
50
60
70
80
Weight of 100 seeds of jatropha of three accessions, Belize, 2009Bullet Tree, nursery
Shell [g]
Kernel [g]
Accessions
We
ight
of 1
00 s
eed
s [g
]
3.Results and discussions
3.2.2 Seed germination rate
After measuring the seed dimensions, 1144 seeds per accession were sown and
germination rate and standing plants were recorded three times. One week after sowing,
the majority of seeds already germinated, however differences among accessions were
noticed; more than 85% of Mexican and Guatemalan seeds germinated, while only 70%
of Belizean seeds germinated after one week. Two weeks after sowing, Mexican seeds
recorded the highest germination rate (96%), followed by Guatemalan (91%) and
Belizean (80%) seeds (Figure 3.11); after that moment, germination was not surveyed
any longer. Standing plants, that are upraised plants with open cotyledons, were counted
at the same time intervals and results were calculated as percentage over sown and
germinated seeds. Significantly different results were obtained for the three genotypes.
At the time of the first survey, less than 3% of jatropha plants from Mexican seeds were
standing, while Guatemalan and Belizean showed standing rates of 37% and 22% over
sown seeds (Figure 3.12) and 44% and 32% over germinated seeds (Figure 3.Error:
Reference source not found). However, two weeks after sowing, more than 99% of
58
Figure 3.10. Length, width, length to width ratio (L:W ratio) and weight of jatrophaseeds as average of a hundred seed sample per accession. Seed accessions arefrom Mexico (low-toxic), Guatemala (G17) and Belize (local). 2009.
Length [cm] Width [cm] L:W ratio Weight [g]
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
2
Average dimensions of jatropha seed of three accessions,Bullet Tree, nursery
Mexico
Guatemala
Belize
3.Results and discussions
plants from germinated seeds of all the accessions were standing (Figure 3.13).
59
Figure 3.11. Germination rate of J. curcas L. seeds of three accessions, on 1144seeds per accession monitored in intervals of 7, 9 and 14 days after sowing. Seedsfrom Mexico (low-toxic), Guatemala (G17) and Belize (local). 2009.
2009.09.23 2009.09.30 2009.10.02 2009.10.07
0
10
20
30
40
50
60
70
80
90
100
Germination rate [%] of 1144 jatropha seeds of three accessions,Belize, 2009 - Bullet Tree, nursery
Mexico
Guatemala
Belize
[%] o
f ge
rmin
ate
d s
eed
s
Figure 3.12. Standing plants as percentage of sown seeds of J. curcas L. of threeaccessions. 1144 seeds per accession monitored in intervals of 7, 9 and 14 daysafter sowing. Seeds from Mexico (low-toxic), Guatemala (G17) and Belize (local).2009.
2009.09.23 2009.09.30 2009.10.02 2009.10.07
0
10
20
30
40
50
60
70
80
90
100
Standing plants as [%] of sown jatropha seeds of three accessions,Belize, 2009 - Bullet Tree, nursery
Mexico
Guatemala
Belize
[%] o
f sta
ndi
ng
pla
nts
3.Results and discussions
In general, Mexican low-toxic seeds showed a slower but more effective germination
characteristic, Guatemalan accession G17 were the quickest plants to stand with a
satisfying germination rate, while Belizean local seeds depicted the lowest, but
acceptable, germination rate and an average standing plant percentage compared to the
other accessions.
3.2.3 Biomass development at nursery stage: LA, fres h weight,
taproot length
During two months at the nursery stage, leaf area (LA) measurements on jatropha
seedlings of the three accessions were performed twice, one month after germination
and at the time of transplanting. The analysis of the variance revealed high significant
differences for the factor 'date' and the interaction 'genotype x date'. In fact, at the first
survey in the beginning of November, no significant differences were found among the
three genotypes. Instead, in the second survey, after a month, significant differences
were found between Mexican and Belizean genotypes, while LA of Guatemalan
60
Figure 3.13. Standing plants as percentage of germinated seeds of J. curcas L. ofthree accessions. 1144 seeds per accession monitored in intervals of 7, 9 and 14days after sowing. Seeds from Mexico (low-toxic), Guatemala (G17) and Belize(local). 2009.
2009.09.23 2009.09.30 2009.10.02 2009.10.07
0
10
20
30
40
50
60
70
80
90
100
Standing plants as [%] of germinated seeds of jatropha of threeaccessions, Belize, 2009 - Bullet Tree, nursery
Mexico
Guatemala
Belize
[%] o
f sta
ndi
ng
pla
nts
3.Results and discussions
seedlings were not significantly different from the other two accessions. Considering the
effect of date separately per accessions, it was found that LA of Belizean seedlings did
not differ significantly between dates, while LA of both Mexican and Guatemalan
seedlings were greater and significantly different at the time of the second survey than
of the first (Figure 3.14).
Additional information about early biomass development of jatropha seedlings came out
from the measurements of taproot length and weight of ten individuals per accession at
the time of transplanting. Results on taproot length analysis indicated that there is a
significant difference, for P=0.05, between Guatemalan and Mexican accessions, while
Belizean accession did not significantly differ from the two other accessions (Figure
3.15). Fresh seedlings of Guatemalan origin seedlings produced more biomass than
others in the first two months of life (Figure 3.16), which can be related to the seed
dimensions, as an indication for the growth reserves available in the seeds. Belizean
accessions with more or less same seed weight but with lower kernel weight (Figure
3.9) grow slower than the other accessions, but invest relatively more dry matter in
61
Figure 3.14. Mean LA of ten jatropha seedlings of three accessions, from Mexico(low-toxic), Guatemala (G17) and Belize (local), measured about one and twomonths after germination. 2009. The same letters above the histograms indicatethat between the treatments significant differences were not found at the Duncantest, with P=0.01.
2009.11.03 2009.11.26
0.000
0.005
0.010
0.015
0.020
0.025
0.030
0.035
0.040
c
a
c
ab
bc bc
LA measurements on jatropha of three accessions, Belize, 2009Bullet Tree, nursery
Mexico
Guatemala
Belize
LA
[m2
*pla
nt-1
]
3.Results and discussions
roots.
Jatropha seedlings dry weight could not be properly measured, since a stove was not
62
Figure 3.16. Fresh weight of ten jatropha seedlings of three accessions, from Mexico(low-toxic), Guatemala (G17) and Belize (local). 2009.
Fresh w eight [g]
0
5
10
15
20
25
Fresh weight of jatropha seedlings of three accessionsBelize, 2009 - Bullet Tree, nursery
Mexico
Guatemala
Belize
[g]
Figure 3.15. Taproot length of ten jatropha seedlings of three accessions, fromMexico (low-toxic), Guatemala (G17) and Belize (local). 2009. The same lettersabove the histograms indicate that between the treatments significant differenceswere not found at the Duncan test, with P=0.05.
Taproot [cm]
0
5
10
15
20
25
30
b
aab
Taproot length of jatropha seedlings of three accessionsBelize, 2009 - Bullet Tree, nursery
Mexico
Guatemala
Belize
[cm
]
3.Results and discussions
available. As a result, two weeks after uprooting and air drying, the young plants' stems
were still green. However, some indicative data were acquired: in two weeks, uprooted
seedlings lost from one quarter to one third by weight; stems were still green and
accounted for the three quarters of the weight; the remaining weight (one quarter) was
divided over roots, petioles and leaves according to the ratio 4:1:4, approximately, for
all three accessions.
3.3 Resources use efficiency and optimization for jatropha
crop conditions in Belize
In the three trials, different agricultural features were considered (plant density in
Central Farm trial, plant spacing in Warrie Head trial and crop management in Maya
Ranch trial). LAI development and effective branch length were recorded in order to
measure part of the plant biomass development and to reveal differences between
different treatments, in view to eventually evaluate resources use efficiency and
optimization for the crop.
3.3.1 Plant density
One week after transplanting jatropha seedlings in Central Farm, LAI measurements
were performed, on December 2nd. Data showed the plant density as the factor that
influenced the LAI values in the different combinations (genotype x plant density). At
the same plant density, no significant differences were found between genotypes (Figure
3.17). Although not significantly different, LAI of Belizean plants were the lowest
among genotypes at high density (circa 2500 plants ha-1) and LAI of Guatemalan plants
were the highest among genotypes at low density (circa 1250 plants ha-1).
63
3.Results and discussions
LAI measurements performed after transplanting in the fields of Central Farm resulted
in smaller values than the ones in the nursery in Bullet Tree, even if occurred one week
after. The reason might be searched in the loss of leaves by the plants during the
transportation from the nursery to the field ('transplanting shock').
3.3.2 Plant spacing
Results from Warrie Head trial deal with LAI and length of effective branch, measured
in four treatments, as a result of the combination of two genotypes (Guatemalan and
Cuban jatropha accession), and two plant spacing designs, single row (4*1m2) and
double (3*1.7)*1.7m2.
To compare the mean values of the four treatments, LAI values are first presented by
date and in a summary graph for all dates. On September 2nd, the only statistically
significant difference was found between the 'Guatemala-double row' plot and the
'Cuba-single row', with LAI values greater than 0.08 in the first one and below 0.06 in
the second. The other two plots, 'Cuba-double row' and 'Guatemala-single row', did not
show statistically significant differences with any of the treatments (Figure 3.18). At the
64
Figure 3.17. LAI measurements of J. curcas L. two month old seedlings of threeaccessions, from Mexico (low-toxic), Guatemala (G17) and Belize (local), at twoplant densities, Central Farm, Belize, 2009.
ca 1250 plants*ha-1 ca 2500 plants*ha-1
0.000
0.001
0.002
0.003
0.004
0.005
c
a
bc
a
c
ab
LAI measurements on jatropha of three accessions andtwo plant densities, Belize, 2009 - Central Farm trial
Mexico
Guatemala
Belize
Plant density
LA
I [m
2*m
-2]
3.Results and discussions
time of the second survey, on October 2nd, no differences were noticed between the LAI
values for the four treatments (Figure 3.19). Later on in the season, statistically
significant differences were observed between LAI values in 'Cuba-double row'
treatment, with more than 0.06m2 of leaf per m2 of soil, and the two accessions in 'single
row', both of them having LAI between 0.03 and 0.04, but these were not significantly
different. LAI of jatropha in 'Guatemala-double row' plot was not significantly different
from the other three treatment (Figure 3.20). Again, towards the end of the growing
season, on December 2nd, no significantly differences were observed between the LAI of
jatropha growing under the four treatments, being at values around 0.025 (Figure 3.21).
65
Figure 3.18. LAI measurements on J. curcas L. on September, 2nd, in Warrie Head,Belize, 2009. The same letters above the histograms indicate that between thetreatments significant differences were not found at the Duncan test, with P=0.01.
Guatemala, (3*1.7)*1.7m2Cuba, (3*1.7)*1.7m2
Cuba, 4*1m2Guatemala, 4*1m2
0
0.01
0.02
0.03
0.04
0.05
0.06
0.07
0.08
0.09 a
ab
b ab
LAI measurements on jatropha, Belize, 2009September 2nd - Warrie Head trial
Treatment (Genotype, Spacing)
LA
I [m
2*m
-2]
3.Results and discussions
66
Figure 3.19. LAI measurements on J. curcas L. on October, 2nd, in Warrie Head,Belize, 2009. The same letters above the histograms indicate that between thetreatments significant differences were not found at the Duncan test, with P=0.01.
Guatemala, (3*1.7)*1.7m2Cuba, (3*1.7)*1.7m2
Cuba, 4*1m2Guatemala, 4*1m2
0
0.01
0.02
0.03
0.04
0.05
0.06
0.07
0.08
0.09
aa
aa
LAI measurements on jatropha, Belize, 2009October 2nd - Warrie Head trial
Treatment (Genotype, Spacing)
LA
I [m
2*m
-2]
Figure 3.20. LAI measurements on J. curcas L. on November, 2nd, in Warrie Head,Belize, 2009. The same letters above the histograms indicate that between thetreatments significant differences were not found at the Duncan test, with P=0.01.
Guatemala, (3*1.7)*1.7m2Cuba, (3*1.7)*1.7m2
Cuba, 4*1m2Guatemala, 4*1m2
0
0.01
0.02
0.03
0.04
0.05
0.06
0.07
0.08
0.09
ab
a
b b
LAI measurements on jatropha, Belize, 2009November 2nd - Warrie Head trial
Treatment (Genotype, Spacing)
LA
I [m
2*m
-2]
3.Results and discussions
An overview of the LAI measurements resulting from monitoring of jatropha in the
Warrie Head plantation from September to December is hereunder provided. Spacing is
influencing LAI of jatropha in the first part of the monitoring period, while effects
caused by genotype are not statistically significant. This behaviour suggests a greater
biomass development capacity in plants in a double row than the ones, more closed, in
the single row, at the same plant density of 2500 trees ha-1. However, the jatropha plants
were relatively young (only fifteen months) and have never been pruned, and they did
not have many lateral branches. Factor 'date' showed its effects especially reducing
differences towards the end of the season. LAI values in 'Guatemala-double row' had a
more gradual reduction towards the end of the growing season than LAI in the other
three treatments. 'Cuba-double row' LAI showed an abrupt difference between
November and December, while LAI of jatropha in 'single row', between October and
December (Figure 3.22). The design of the Warrie Head experiments were blocked
perpendicular on the slope gradient; however, it might be that the location of the
'Guatemala-double row' treatment, closer to the margins of the forest and to the river,
could have attenuated the effects of the weather variables along the season, especially in
67
Figure 3.21. LAI measurements on J. curcas L. on December, 2nd, in Warrie Head,Belize, 2009. The same letters above the histograms indicate that between thetreatments significant differences were not found at the Duncan test, with P=0.01.
Guatemala, (3*1.7)*1.7m2Cuba, (3*1.7)*1.7m2
Cuba, 4*1m2Guatemala, 4*1m2
0
0.01
0.02
0.03
0.04
0.05
0.06
0.07
0.08
0.09
a a a a
LAI measurements on jatropha, Belize, 2009December 2nd - Warrie Head trial
Treatment (Genotype, Spacing)
LA
I [m
2*m
-2]
3.Results and discussions
the drought of October. Moreover, the analysis of the variance highlighted differences
among the blocks, with the block in the middle having generally higher values than the
ones on the sides.
Additional information on jatropha growth potentials is obtained through the calculation
of intercepted radiation by the plants in the growing season. As they are mainly
depending on the LAI, values of intercepted radiation are following the same LAI trends
discussed above. Solar radiation was slightly decreasing from September to December,
however, due to limited interception capacity of the low LAI, plants were only able to
use a small amount of the available radiation (Figure 3.23; note the log scale). This
situation might suggest a potential improvement of solar radiation use by jatropha, in all
the situations. Basically, to improve radiation interception, LAI should be increased by
management actions that, on the one hand, induce more and larger branches and leaves
that stay green longer in the season, such as pruning (strongly recommended as the
plantation is still young), and, on the other hand, increase plant density and plant
capability to completely close the rows, such as spacing at transplanting and curbing
68
3.Results and discussions
branches, thus to optimize the use of available space.
The 'effective branch' length measurements supported the results obtained for LAI,
although not completely, highlighting statistically significant differences between dates,
October 2nd and December 2nd (Figure 3.24) and blocks. No significant differences were
found between genotypes and spatial arrangement of the rows. The lengths of effective
branch in Warrie Head trial were similar to the ones in Maya Ranch, during the same
dates of survey, mainly around 10-12cm in November and 4-5cm in December.
However, in relative terms, length of effective branch was almost double in Maya
Ranch than in Warrie Head, being around 20% and 10% of the whole branch length in
the first site and around 10% and 5% in the second, in the dates considered (Figure
3.25).
69
Figure 3.23. Solar radiation, LAI of jatropha under different treatments (combinations of twogenotypes and two spacings: Guatemala-double row, Cuba-double row, Cuba-single row andGuatemala-single row) and intercepted radiation are represented from September to December,in Warrie Head, Belize, 2009.
S O N D S O N D S O N D S O N D
0.01
0.1
1
10
100
Solar radiation, jatropha LAI and intercepted radiation, Belize, 2009Warrie Head trial
Radiation [kJ m -2 d-1]
LAI [m2 m-2]
Intercepted radiation [kJ m -2 d-1]
Treatment (from left to right: Guatemala- and Cuba-double row, Cuba- and Guatemala-single row )and date (September, October, November, December)
3.Results and discussions
70
Figure 3.24. Length of the 'effective branch' (part of the branch with green leaveson), in J. curcas L., Warrie Head, Belize, for October 2nd, November 2nd andDecember 2nd, 2009. The same letters above the histograms indicate that betweenthe treatments significant differences were not found at the Duncan test, withP=0.01.
Guatemala, (3*1.7)*1.7m2Cuba, (3*1.7)*1.7m2
Cuba, 4*1m2Guatemala, 4*1m2
0
5
10
15
20 a
ab
aa
abc abcabc
abc
c c bcbc
Jatropha 'effective branch' length, Belize, 2009Time series - Warrie Head trial
2009.10.02
2009.11.02
2009.12.02
Treatment (Genotype, Spacing)
Effe
ctiv
e b
ran
ch [c
m]
Figure 3.25. Relative length of the 'effective branch' (part of the branch with greenleaves on) as percentage of the whole branch, in J. curcas L., Warrie Head, Belize,for October 2nd, November 2nd and December 2nd, 2009.
Guatemala, (3*1.7)*1.7m2Cuba, (3*1.7)*1.7m2
Cuba, 4*1m2Guatemala, 4*1m2
0
5
10
15
20
25
Jatropha 'effective branch' relative lenght, Belize, 2009Time series - Warrie Head trial
2009.10.02
2009.11.02
2009.12.02
Treatment (Genotype, Spacing)Effe
ctiv
e b
ran
ch a
s [%
] of t
ota
l bra
nch
3.Results and discussions
3.3.3 Crop management
As in the case of Warrie Head trial, assessing jatropha biomass development was the
objective of the research in the Maya Ranch plantation, as well. Results from Maya
Ranch trial refer to yield, LAI and length of the effective branch.
Firstly, results from fruit and seed production are given. It must be underlined that yield
values are referred to as dry weight production. Separately, for the two plots considered
and for the two dates of harvesting, yield values are given under three forms: reported as
harvested per plot, as an average per plant and extrapolated to a unit surface basis (kg
ha-1). Data are indicating different production potentials in the plots considered (Table
3.1). Over the season, in the treatment 'Not pruned', where plants have never been
pruned and were growing in intercropping with A. pintoii, jatropha fruit production was
double than the one in the treatment 'Pruned', where, instead, jatropha plants were
growing in monoculture and have been pruned two years before (Figure 3.26).
Specifically, fruit production from 'Not pruned' treatment was almost triple at the
moment of the first harvest and one tenth higher at the second harvest. However, fruit
production trends revealed important differences between the time of the two harvests;
in fact, during the season, production from 'Not pruned' treatment decreased almost by a
half, while production from 'Pruned' plot increased by 70% (Figures 3.27 and3.28).
Cautiously, it has to be reminded here that production losses seemed to be significant: in
fact, by the time of the first harvest, fruits were already on the ground and have not been
collected; moreover, after the second and last harvest, fruits have been seen on the
plants and on the ground up till mid November, and some plants were still flowering in
October. These considerations suggest that potential production is bigger than measured,
although it is difficult to determine how bigger. An estimation of the production that
could not be harvested may be possible, considering the fruiting period (mid July to end
October), the harvested yield in the period from July 27th to August 10thand its trend for
the different treatments, the average dry fruit production per plant (0.26kg for 'Not
pruned' and 0.14kg for 'Pruned' treatment), the number of branches per plant (23 for
'Not pruned' and 16 for 'Pruned' treatment), the fruit ripening period (40-80 days), the
71
3.Results and discussions
LAI development and the weather variables trends. It may be concluded that dry fruit
potential yields would have been around 400-450kg in 'Not pruned' treatment and
around 250-300kg in 'Pruned' treatment.
72
Table 3.1. Dry fruit production of J. curcas L. with two treatments:i)never pruned and in intercropping with A. pintoii (Not pruned), and ii)pruned two years before and in monoculture (Pruned), in MayaRanch, Belize, 2009.
Fruit Production Not pruned PrunedArea (m2) 1728 960# of plants 216 120Yield 2009.07.27 (kg) 37 7
kg*plant-1 0.17 0.06kg*ha-1 214 73
Yield 2009.08.10 (kg) 20 10kg*plant-1 0.09 0.08
kg*ha-1 116 104Total yield (kg) 57 17
kg*plant-1 0.26 0.14kg*ha-1 330 177
Figure 3.26. J. curcas L. dry fruit, dry seed and kernel total productions for 'Notpruned' and 'Pruned' treatments, in Maya Ranch, Belize, 2009. Jatropha plants weregrowing in intercropping with A. pintoii and have never been pruned ('Not pruned'treatment) or were growing in monoculture and have been pruned two years before('Pruned' treatment).
Not pruned Pruned
0
50
100
150
200
250
300
350
Total jatropha yield, Belize, 2009Maya Ranch trial
Fruit [kg*ha-1]
Seed [kg*ha-1]
Kernel [kg*ha-1]
[kg
*ha-
1]
3.Results and discussions
Further measurements and calculations on the harvested yield have been undertaken to
establish dry matter assignment in the fruit. Seed to fruit ratio and kernel to seed ratio
73
Figure 3.27. J. curcas L. dry fruit, dry seed and kernel productions from 'Not pruned'treatment, represented by harvests on the 27th July and 10th August, in Maya Ranch,Belize, 2009. Jatropha plants were growing in intercropping with A. pintoii.
2009.07.27 2009.08.10
0
50
100
150
200
250
Jatropha yield from 'Not pruned' plot, Belize, 2009Maya Ranch trial
Fruit [kg*ha-1]
Seed [kg*ha-1]
Kernel [kg*ha-1]
[kg
*ha-
1]
Figure 3.28. J. curcas L. dry fruit, dry seed and kernel productions from 'Pruned'treatment, presented by harvests on the 27th July and 10th August, in Maya Ranch,Belize, 2009. Jatropha plants have been pruned two years before and were growingin monoculture without intercropping.
2009.07.27 2009.08.10
0
50
100
150
200
250
Jatropha yield from 'Pruned' plot, Belize, 2009Maya Ranch trial
Fruit [kg*ha-1]
Seed [kg*ha-1]
Kernel [kg*ha-1]
[kg
*ha-
1]
3.Results and discussions
were calculated, separately per date and per treatment. On a dry matter basis, seed
weights were 70.5% to 74.3% of the dry fruit weight; while kernel weight was between
63% and 65% of the dry seed weight (Table 3.2).
A thousand dry fruit sample was randomly collected from the whole production of the
trial: seed dry matter was about 71% of dry fruit weight, which agreed with previous
measurements (Table 3.3). An average value 2.65 seeds per fruit was recorded (Table
3.4).
74
Table 3.2. Dry fruit weight, seed to fruit ratio and kernel to seed ratio of J. curcas L. in twotreatments: i)never pruned and in intercropping with A. pintoii ('Not pruned'), and ii) prunedtwo years before and in monoculture ('Pruned'), in Maya Ranch, Belize, 2009.
2009.07.27 2009.10.08 Total 2009Not pruned Pruned Not pruned Pruned Not pruned Pruned
Fruit (kg) 37 7 20 10 57 17Fruit sample (g) 740 140 400 200 1140 340
of which seed (g) 530 104 282 141 812 245Seed:Fruit (%) 71.62 74.29 70.5 70.5 71.23 72.06Seed sample (g) 100 100 100 100 200 200
of which kernel (g) 64 65 63 65 127 130Kernel:Seed (%) 64 65 63 65 63,5 65Fruit (kg*ha-1) 214 73 116 104 330 177Seed (kg*ha-1) 153 54 82 73 235 128
Table 3.3. J. curcas L. fruit coat to seed ratio, on a dry weight basis, fromone thousand dry fruit samples randomly collected in Maya Ranch, Belize,2009.
DRY ITEM QUANTITY (#) WEIGHT (g) (%)Fruits 1000 1681 100.00Coats 1000 485 28.85Seeds 2648 1196 71.15
Table 3.4. Number of seeds per fruit of J. curcas L., from onethousand dry fruit samples randomly collected in MayaRanch, Belize, 2009.
Number of fruits with: (#)4 seeds 23 or 2 seeds 9621 seed 36Average # of seeds*fruit-1 2.65
3.Results and discussions
At Maya Ranch trial, further research was carried out to determine biomass
development by monitoring LAI and length of the effective branch. At the time of the
first survey, on September 1st, monitored plants were grouped according to their
management (Not pruned/Intercropping, Pruned/Monoculture or Not
pruned/Monoculture), showed LAI values between 0.7 and 0.8 for the
'Pruned/Monoculture' and the 'Not pruned/Intercropping' treatments, which were
significantly larger than the values of 'Not pruned/Monoculture' treatment (Figure 3.29);
although, this difference was not significant later on the season. LAI values were much
smaller (around 0.2; Figures 3.30, and 3.31) for the Not pruned/Monoculture treatment.
LAI values reported in Maya Ranch are altogether presented in Figure 3.32, where
management and date effect can be visually compared.
75
Figure 3.29. LAI measurements on J. curcas L. on September, 1st, in Maya Ranch,Belize, 2009. The same letters above the histograms indicate that between thetreatments significant differences were not found at the Duncan test, with P=0.01.
Not pruned/Intercropping Pruned/Monoculture Not pruned/Monoculture
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9a
a
b
LAI measurements on jatropha, Belize, 2009September 1st - Maya Ranch trial
Management
LA
I [m
2*m
-2]
3.Results and discussions
76
Figure 3.30. LAI measurements on J. curcas L. on November, 1st, in Maya Ranch,Belize, 2009. The same letters above the histograms indicate that between thetreatments significant differences were not found at the Duncan test, with P=0.01.
Not pruned/Intercropping Pruned/Monoculture Not pruned/Monoculture
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
a
a
a
LAI measurements on jatropha, Belize, 2009November 1st - Maya Ranch trial
Management
LA
I [m
2*m
-2]
Figure 3.31. LAI measurements on J. curcas L. on December, 1st, in Maya Ranch,Belize, 2009. The same letters above the histograms indicate that between thetreatments significant differences were not found at the Duncan test, with P=0.01.
Not pruned/Intercropping Pruned/Monoculture Not pruned/Monoculture
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
aa
a
LAI measurements on jatropha, Belize, 2009December 1st - Maya Ranch trial
Management
LA
I [m
2*m
-2]
3.Results and discussions
Values of intercepted radiation by jatropha plants in Maya Ranch trial followed the
same trends discussed for the LAI. Solar radiation values are the same as for Warrie
Head, since they have been recorded in the same meteorological station. It is clear that
there is a considerable loss of solar radiation by jatropha in all the situations, over the
season (Figure 3.33; note the log scale). Similar management actions as discussed for
plantation at Warrie Head should be undertaken.
77
Figure 3.32. LAI measurements on J. curcas L. in Maya Ranch, Belize, 2009. Data arepresented in time series, according to the surveys over the season, occurred in September 1st,November 1st and December 1st. The same letters above the histograms indicate that betweenthe treatments significant differences were not found at the Duncan test, with P=0.01.
Not pruned/Intercropping Pruned/Monoculture Not pruned/Monoculture
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9a
a
bb
b
b
bb b
LAI measurements on jatropha, Belize, 2009Time series - Maya Ranch trial
September
November
December
Management
LAI
[m2
*m-2
]
3.Results and discussions
The lengths of the effective branch have been recorded twice during the season and
results showed values of 12cm to 18cm on November 1st and around 4cm on December
1st. However, treatments did not evidence statistically significant differences on
effective branch length, while differences appeared considering the date of survey
(except in the case of 'Pruned/Monoculture' plot).Overall, the longest effective branch of
'Not pruned/Monoculture' plot in November and the shortest of 'Not
pruned/Intercropping' plot in December have been pinpointed (Figure 3.34). In figure
3.35 the length of the effective branch in relation to the total length of the representative
branch is presented.
78
Figure 3.33. Solar radiation, LAI of jatropha under different treatments (managements: Notpruned/Intercropping, Pruned/Monoculture and Not pruned/Monoculture) and interceptedradiation are represented from September to December, in Maya Ranch, Belize, 2009.
S O N D S O N D S O N D
0.01
0.1
1
10
100
Solar radiation, jatropha LAI and Intercepted Radiation, Belize, 2009Maya Ranch trial
Radiation [kJ m -2 d-1]
LAI [m2 m-2]
Intercepted radiation [kJ m -2 d-1]
Treatment (from left to right: Not Pruned/Intercropping, Pruned/Monoculture, Not Pruned/Monoculture)and month (September, October, November, December)
3.Results and discussions
Regrettably, the survey could not be completed over the whole growing season, so the
growth curve for LAI and length of the effective branch can not be presented.
79
Figure 3.34. Length of the 'effective branch' (part of the branch with green leaveson), in J. curcas L., Maya Ranch, Belize, for November 1st and December 1st, 2009.The same letters above the histograms indicate that between the treatmentssignificant differences were not found at the Duncan test, with P=0.01.
Not pruned/IntercroppingPruned/Monoculture
Not pruned/Monoculture
0
4
8
12
16
20
ab abc
a
c bc bc
Jatropha 'effective branch' length, Belize, 2009Time series - Maya Ranch trial
2009.11.01
2009.12.01
Management
Effe
ctiv
e b
ran
ch [c
m]
Figure 3.35. Relative length of the 'effective branch' (part of the branch with greenleaves on) as percentage of the whole branch, in J. curcas L., Maya Ranch, Belize,for November 1st and December 1st, 2009.
Not pruned/IntercroppingPruned/Monoculture
Not pruned/Monoculture
0
5
10
15
20
25
30
35
40
Jatropha 'effective branch' relative length, Belize, 2009Maya Ranch trial
2009.11.01
2009.12.01
ManagementEffe
ctiv
e b
ran
ch a
s [%
] of t
ota
l bra
nch
3.Results and discussions
It is noted that there is a sudden lowering of LAI values in the period September –
November, especially in 'Not pruned/Intercropping' and 'Pruned/Monoculture'
treatments; while in the period November – December LAI measured in the same
treatments is decreasing much slower, and even is increasing in 'Not
pruned/Monoculture' treatment, although differences are not significant. This fact can be
linked with the relatively low precipitation in October and a remarkable restart of the
rainfall in November and December. The additional information, provided by the length
of effective branch, suggest that between November and December the branch length in
which green leaves were growing was reduced but the leaf area did not vary, since
effective branch length decreased while LAI values kept being similar. Indeed, from
November to December, some leaves died thus reducing the space occupied on the
branch and some others leaves grew or in area or in number. Due to the favourable
precipitation events in November and December, jatropha might have developed and
increased the area of the already existing leaves or a new significant sprouting might
have occurred.
Observations in the two experimental sites (6 year old Maya Ranch and 1.25 year old
Warrie Head) lead to the following considerations. Results on biomass development
(LAI and effective branch) suggest that, even if the length of representative branch was
recorded to be greater in Warrie Head trial, jatropha plants in Maya Ranch had a
significantly larger LA and longer segments of branch with green leaves and more
branches. The reason for this is the different age, management (pruning and plant
density), genotype and degree of adaptation to the location; therefore, reasons of
different plant development should be cautiously studied.
3.4 Discussions
Field research in Belize allowed to monitor Jatropha curcas L. growth and development
under a wide range of conditions. Many different environmental variables have
influenced jatropha growth in the surveyed trials. Trials in Maya Ranch, Warrie Head,
80
3.Results and discussions
Central Farm (and Bullet Tree) represent a wide range of different environmental factors
and differences in plant genotype, age, crop management (treatments: pruning,
intercropping, spacing), that unravelling the effects among these factors in jatropha
growth and development is challenging. At this point in time, after a relatively short
period of on field research, it is difficult to weigh the outputs and quantify the outcomes
of all the experiments considered. Last but not least, there may exist a difference in
weather variables that could not be specified per location, since the same meteorological
stations were used in the experimental sites. Some constraints were encountered and
scientific logic had to be developed in the process. Observations for the three trials with
possible comparisons are highlighted and specific actions on further research activity
are suggested.
As far as it is known, Belizean oldest jatropha plantation is located in Maya Ranch and
it has to be considered a valuable source of information. The present investigation
provides additional information to research previously undertaken in Maya Ranch. So
far, it looked like jatropha in Maya Ranch received a benefit from the intercropping with
Arachis. Not pruned plants might have larger biomass development, while pruned plants
keep both leaf and fruit production slightly delayed in the season: the reasons could be
that the plants still invest more biomass in new branches and have a more compact but
intense growth. Drought in October might have negatively affected leaves development,
but re-occurring rains in November restored the plants. Management actions, such as
weeding, could have influenced jatropha growth more, by eliminating those plants that
compete for resources and by leaving the vegetable material in the field, as organic
fertilizer. In general, the jatropha plantation at Maya Ranch is looked after with interest
and this potential could be valued even more, since a selection within the local genetic
resources could start from here. To follow this aim, production per single plant in a
defined production system need to be assessed, in order to start a selection that would
eventually lead to a breeding program. For this purpose, harvested seed should be
isolated per tree and number of fruits per inflorescence should be monitored. The seed
production reached in 2009 does not justify a commercial implementation of the crop.
81
3.Results and discussions
Measures have to be undertaken in order to increase the production. An action to
improve crop production is making better use of the available space, that is to occupy
the inter- an intra-row space in order to give the plant a better chance of developing
lateral branches, bringing along the benefit of reducing weed growth; bending long
branches downward without breaking them could have a beneficial impact in order to
achieve the mentioned objective; also in this sense, knowledge in jatropha cultivation is
increasing and suggestions are made about yearly pruning in the dry season, setting
principal branches at about 50cm from the ground, leaving about 20cm of the original
branches and about 7-8 branches per plant (Stanningen, personal comm.). Moreover, it
has to be understood why, within the plot, some plants are weaker, smaller and were not
yielding; with regard to this, soil analysis are strongly recommended. After all, Maya
Ranch is an ideal place where to test different management actions on local genetic
material, so to analyse the responses and elaborate a jatropha cultivation decision-
support system.
The Warrie Head trial is set up with some of the considerations mentioned for Maya
Ranch, with a few exceptions. At Warrie Head, the plantation is five years younger and
three times bigger, and moreover it involves different genotypes and management
treatments. In general, LAI values measured in Warrie Head trial were, even at a double
plant density, about ten times smaller than the ones measured in Maya Ranch. Plant
spacing, at Warrie Head plantation, played a significant role in LAI development, with
the 'double-row' system being more efficient, even if plant architecture (single stem) of
both systems and genotypes did not appear the most efficient for optimized seed
production. Firm actions should be undertaken, i.e. start with pruning to induce
branching (Stanningen, personal comm.). The crop in Warrie Head might have suffered
from the drought in October, as well, and the response to the unexpected rains in
November was not so evident. For further investigations, consequences of intercropping
or application of effective microorganism should be analysed. Furthermore, the Cuban
accession (referred to as 'Cabo-Verde') should be surveyed, as 'Cabo Verde' is the most
productive accession to date in many areas. Further research could be implemented
82
3.Results and discussions
since an irrigation system is available, where river water can be used to overcome water
shortage. At this point and time, TSDF together with the Energy and Environment
Partnership (EEP) is aiming to continue the research and the set up of a breeding
program should bring along beneficial consequences also in this situation. Further
investigations both in Warrie Head and Maya Ranch would necessarily have to deal
with the fact that plants were already in the ground and some factors would have to be
considered fixed; in any case the surrounding environment is promising and
expectations are high.
Adding knowledge and experience to current research is the jatropha plantation in
Central Farm, one of the latest pilot project set up in Belize, thanks to the ERA-ARD
transnational call. Results of the first three months of surveying, since its original
implementation, brought to considerations that should be discussed with similar trials
within the net. According to the data analysis, it seemed that the largest seeds, from
Guatemalan accession G17, resulting in a considerable germination rate, gave also the
largest amount of biomass in seedlings. The low-toxic accession from Mexico and the
local accession from Belize showed different germination patterns, but eventual
biomass development did not differ significantly. Mexican low-toxic accession seemed
to have a superior germination power resulting in the highest germination rate and a
discrete degree of adaptation for its greater increase in LA between the two dates of
survey. Belizean local accession, instead, showed satisfying patterns of germination,
growth and development, although considered average when compared to the other two
accessions. A selection of plant material should be done as the next step in developing
Belize jatropha scenario. Hopefully, the project outputs will contribute to a beneficial
application of jatropha system in Belize and worldwide. A summary of results of this
work is reported in the column 'Research in Belize', in tables a,b,c and d of annex 1.
83
4. Conclusions
Energy demand and environmental awareness are pushing world community to search
for alternatives to fossil fuels, both in developing and developed countries. With regard
to this search for alternatives, a significant question is emerging about new energy
source, what choice should at the same time mitigate global warming, reduce oil
dependence, and, possibly, improve quality of life globally. Thence, numerous solutions
to face energy hunger worldwide, without compromising the health of the planet, seem
available nowadays and may vary according to regional peculiarities. In fact, issues,
such as food security, land property and division, technology availability, market
competition, social disparity and natural constraints among others, might affect local
and regional decision-making processes towards selection and definition of a
sustainable energy system. In this sense, comprehensive policies are strongly
recommended to initiate such sustainable energy process, together with the
implementation of research and development projects on new suitable energy sources.
The present research investigated the cultivation of Jatropha curcas L., as one of the
potential candidate crops as renewable energy source in Belize is, indeed, jatropha
vegetable oil. This crop appears to be a suitable and valuable option to meet the needs
of the country because of its remarkable features. Findings and challenges that the start
up of a jatropha based bioenergy system would bring are hereunder discussed.
The implementation of jatropha cultivation in Belize is an opportunity because of the
following good reasons. Jatropha is native to Belize, and researches suggested genetic
resources availability and a proper pedoclimatic situation for its growth and
development in the country. Moreover, land is available and the integration of jatropha
in existing farming systems (especially intercropping and agro-forestry systems) or its
use as hedge seem feasible and helpful, as its cultivation is easy to implement at a
small-farm scale and low technology inputs are required. In fact, being a perennial
drought tolerant energy crop brings to a series of positive patterns, even at low seed
production levels: there are no needs for fulfilment of annual agricultural practices that
often require appropriate machinery and structures (e.g. tillage, sowing); it withstand the
possibility of one or more years of interruption of cultivation for climatic or human
reasons; its cultivation provides valuable co-products such as leaves,latex, fruits coats,
4.Conclusions
seed cake and shells for medicinal uses, fertilizers, insecticides, soap production or
combustibles, as well, according to researchers' judgements and findings in similar
agro-ecological zones (Baldrati, 1950; Heller, 1996; Rijssenbeek and Togola, 2007;
Kumar and Sharma, 2008; Jongschaap et al., 2007; Achten et al., 2008; Ogunwole et
al., 2008). Low technology inputs are required on the cultivation step ,where most of
the management actions are done manually (pruning and harvesting, mainly), and on oil
processing. In fact, BD20 blends (20% of vegetable oil and 80% of diesel) are possible
and, after all, would greatly reduce Country costs for energy.
In Belize, interests on jatropha have been shown at local national and regional levels. In
the Country, the Ministry of Agriculture is going to start up a five acre jatropha pilot
plantation to optimize the agro-technology and bring it to farmers (Martinez, personal
comm.); private investors are increasing since few years, both for research purposes and
commercial activity set up; the NGO Tropical Studies and Development Foundation
Belize is conducting research projects together with the Energy and Environment
Partnership (EEP), the Organization of the American State (OAS), the ERA-ARD net,
and its role as pioneer on jatropha research throughout the Country is remarkable. At
regional level, Central America and Caribbean Countries are cooperating and pushing
for a concrete development of bioenergy regulations and for a deep technology research.
Particularly, Belize, represented by the Ministry of Agriculture, the University of Belize
and TSDF, signed a Memorandum of Understanding, planning further collaboration and
research together with Colombia, Costa Rica, El Salvador, Guatemala, Honduras,
Mexico, Nicaragua, Panama and Dominican Republic at the 'First Reunion of the
Biofuels Research and Development Network' of the Mesoamerican Project (Primera
Reunión de la Red Mesoamericana de Investigación y desarrollo en Biocombustibles,
23-27 de Agosto, 2009, Tuxtla-Gutierrez, Chiapas, México). With regard to this,
institutional strengthening at national and regional scale is recommended, and, in
Belize, the creation of a platform to host highly scientific researches and knowledge
exchange would be very welcome.
Next steps that would allow to unravel jatropha potentials in Belize include: the
86
4.Conclusions
selection of high-yielding individuals and the set up of a breeding programme;
feasibility studies of jatropha cultivation in different Districts; regulation of bioenergy
sector, to promote the birth of an equitable market for jatropha and other bioenergy
products. What is more, the existing knowledge should be integrate with next findings
and the wide range of possibilities linked to a jatropha production system should be
shared with farmers and growers associations. Ultimately, as motivating the first actors
(the farmers) in this value chain is essential, possibilities should be exhaustively
investigated both on developing agro-forestry applications suitable in Clean
Development Mechanism projects or other rural development and bioenergy projects
and, what is more, oil extraction and processing technology should be brought and
developed in Belize.
87
5. Acknowledgements
All around the world, many friends and tutors I met along the road and I thank them all
for helping and talking and walking with me to the slopes of the mountain. My sincere
gratitude goes to Sylvia and Alex Laasner and TSDF Belize, who welcomed me from
the very beginning until the last day, providing the basic equipment to carry out the
research activity in the field and in the office and indicating me the borderline between
the 'endless research' and the implementation of research findings into concrete actions;
to Michael Rosberg, Marion Cayetano and Sylvia Carillo from Galen University, who
stimulate a debate on jatropha (and helped me getting the visa); to Dr. Holder, Dr.
Mendez and Maynor Hernandez from University of Belize, for their essential
collaboration; to Ann Gordon and Michelle Smith of the National Meteorological and
Hydrological service for their most valuable contribution in providing all the climatic
data; to Eva, Toby, Alan and all TSDF team, who could translate theory to practice,
implementing the experimental design so efficiently; to the Mexican Secretary of
Foreign Affairs and to COCyTECH and the State of Chiapas, Mexico, who permitted to
bring the debate on bioenergy and jatropha at international level, fostering cooperation
and knowledge exchange between Central American States, during the First Reunion of
the Mesoamerican Network on Biofuels Research and Development in Tuxtla-Gutierrez,
Chiapas; to Pio Saki from the University of Belize and to Clifford Martinez from
Belizean Ministry of Agriculture, who joined me, as TSDF representative, and
represented Belize in that reunion; to Hans Stanningen, for sharing his knowledge on
jatropha cultivation; to John and Richard, to the friends of 6, Bladen street, especially
Mrs Flores and her familiy and, the best chess player, nurse Robert John Ilao, to take
care of me and make my experience in Belize more sustainable. Some friends, in Belize,
are pictured in figures 5.1, 5.2, 5.4 and 5.3.
I thank professor Berti, for the valuable contribution on structuring the statistical
analysis of this thesis.
My gratitude also goes to my friends and my family in Italy, to Papà, who stimulates a
critic dialogue on agriculture, together with Diego and my friends of studies Mariano,
Lorenzo, Marco, Alvise, Alessandro, Giulio and Linda; to Mamma, Clara, Nicola,
5.Acknowledgements
Maria, Girolamo and all the members of my family to support (and 'sopport') me until
here, especially Zia Agnese, who taught me the first steps in the world of Research, and
Zia Lavinia, who constantly stimulate my research and interests forwarding me
agricultural information and news on jatropha. I thank my grandparents Nonna Paola
and Nonno Berardo, Nonna Clara and Nonno Beppi, for their best lessons of life, being
the most precious model I have ever known. Last but not least, I thank Valentina, for
patiently reviewing drafts of this M.Sc. thesis, finding better expressions, being an
outsider, and for showing me the power of love.
I apologize if I missed someone but I guarantee: I did not forget anyone.
90
Figure 5.2. Transplanting jatropha with Toby,Alan and TSDF team, in Central Farm,Belize, November 2009.
Figure 5.1. Harvesting with Rubelio and histwo brothers, in Maya Ranch, Belize, July2009.
Figure 5.4. Surveying jatropha plantations,with Hans Stanningen and Toby Sengfelder,Cayo District, Belize, October, 2009.
Figure 5.3. Surveying jatrophaplantations, with RaymondJongschaap, Cayo District,Belize, October, 2009
Annex 1. Growth parameters and sustainabilityindicators tables
Annex 1a. Growth parameters by plant part
(continues in the next page)
Growth Parameter Unit or evaluating pm Measurement Lite rature ResearchSEED in Belize
Seed germinability % Kaushik et al., 2007 80-96Seed germination energy days to germination 10 Henning, 2007Seed yield (dry seed) t*ha-1*yr-1 1.5-7.8 Jongschaap et al., 2007Seed size length (cm) 1-2 Henning, 2007 1.8-1.9
width (cm) 1-1.1HI-seed kg*kg-1 0,35 Jongschaap et al., 2007100-seed weight g 63 Singh et al., 2008 54-731000-seed weight g 400-730 Henning, 2007Shell:Kernel ratio by DM % 34.3:65.7 Openshaw, 2000; Singh et al., 2008 33-37:63-67Oil content in seed % 33.6-37.0 Rivera Lorca and Ku Vera, 1997Oil content in kernel % 21-74 Shah et al., 2005Oil yield l*ha-1 439-2.217 Jongschaap et al., 2007HI-oil l*kg-1 0,1 Jongschaap et al., 2007Oil quality Different compounds and composition Henning, 2007; Jongschaap and van Loo, 2009DMA-seed % 32 Jongschaap (personal comm.)DMA-shell % 11 Jongschaap (personal comm.)DMA-kernel % 21 Jongschaap (personal comm.)Nutrient composition (NPK, …) % existing data Jongschaap et al., 2007
ROOT# roots*plant-1 n Kaushik et al., 2007Length (aft. 90 days) cm 10-17 Kaushik et al., 2007Root hairs yes/noExplored area by roots cm³Water uptake mm*ha-1Nutrient uptake (NPK) kg*ha-1*yr-1 existing data Jongschaap (personal comm.)Mychorrization (after inoculation) yes/no yes Jongschaap et al., 2007DMA % 8 Jongschaap (personal comm.)Nutrient composition (NPK, …) % existing data Jongschaap et al., 2007
STEM/WOODCuttings survival rate (T,M,B) % 42-72-88 Achten et al., 2008Seedling survival rate % 95-100 Kaushik et al., 2007Total height (aft. 90 days) cm 29-47 Kaushik et al., 2007Total height m 1.15-1.34 Kaushik et al., 2007Collar diameter (aft. 90 days) cm 8-11 Kaushik et al., 2007Crown size m 1.25-1.52 Kaushik et al., 2007
n 25 Henning, 2007Apical dominance low/highDMA % 23 Jongschaap (personal comm.)Nutrient composition (NPK, …) % existing data Jongschaap et al., 2007
LEAF# leaves*plant-1 (aft. 90 days) n 13-20 Kaushik et al., 2007Leaf size length (cm) 7-18 Henning, 2007
width (cm) 5.5-18 Henning, 2007LA m²leaf*plant-1Light interception k 0.55-0.68-0.75Clorophyll content SPAD values existing data Jongschaap (unpublished data)PET, AET mm*day-1Photosyntetic activity existing data Jongschaap (unpublished data)DMA % 23 Jongschaap (personal comm.)Nutrient composition (NPK, …) % existing data Jongschaap et al., 2007
FLOWER# male flowers*plant-1 n# female flowers*plant-1 nMale:female ratio n 13:1, 29:1 Achten et al., 2008Location of flowers Female major axis, male lateral, branch age Henning, 2007Cross:self-pollinated Abdelgadir et al., 2008Pollination actors Moths yes(/no) Henning, 2007
Honeybees yes(/no) Abdelgadir et al., 2008Small flower and abortion % up to 60 Jongschaap et al., 2007
FRUIT# fruits*plant-1 n 24-240# fruits*branch-1 n 3-8Fruit size length (cm) 2.5 Singh et al., 2008Fruit setting %Ripening days 90Coat:Seed ratio by DM n 30:70 Openshaw, 2000 29:71HI-fruit kg*kg-1 0.50 Jongschaap et al., 2007DMA % 46 Jongschaap (personal comm.)DMA-coat % 14 Jongschaap (personal comm.)Nutrient composition (NPK, …) % existing data Jongschaap et al., 2007
89 (a)7-14 (a)
0.13-0.24 (b)
8-16 (j)19-25 (c)
17-20 (c)0.5-2.5 (d); 2-4 (e)
# branches*plant-1 (optimum) 1-4 (d); 11-40 (e)Montes et al., 2008 (f)
1-5 (c)
0.02-0.9 (k)Jongschaap (unpublished data) (g)
Annex 1. Growth parameters and sustainability indicators tables
(a) The value may vary according to different pre-treatments.
(b) Data not fully reliable for Belize (see section 3.2).
(c) 60 days after sowing.
(d) 1 year old plantation.
(e) 6 years old plantation.
(f) It is reported variability in plant architecture among different accessions.
(g) 'k' varies according to LAI values, respectively >7; 7>LAI>1,5; <1,5.
(h) Plant breeding still in its infancy.
(i) Calculated on Minimum and Maximum monthly values in the growing season (June – December 2009).
(j) At different planting times.
(k) According to plant age and period during the growing season.
94
PLANT Growth Parameter Unit or evaluating pm Measurement Lit erature in BelizePlant energy efficiencyNutrient cycles (macro/micro) Chaudary et al., 2008Plant potential lifespan years 30-50 Henning, 2007
GenotypeFitness (h)
HormonsQualityQuantityLocation in plant organs
Stress toleranceAbiotic Temperature (optimum) °C 20-28 Achten et al., 2 008;
Rainfall (optimum) mm*ha-1*yr-1 1000-1500 Daey Ouwens et al., 2007 1476R.U. %
RadiationVapour pressure kPaWind speed m*s-1
Biotic Pest (types) Phytophagous, powdery mildew; more Henning, 2007; Daey Ouwens et al., 2007Disease (types and plant organ) Cassava mosaic virus; more Henning, 2007; Daey Ouwens et al., 2007Nutrient competitionWater competitionEnergy competition
20-33 (i)
kJ*m-2*d-1 12-17 (i)28-32 (i)4-6 (i)
Annex 1b. Growth parameters by crop system
(a) It should always be specified for a complete understanding of following data.
CROP SYSTEMGrowth Parameter Unit or evaluating pm Measurement Lit erature Research
Monoculture in Belizeplants*ha-1 1100-2500 Heller, 1996; Henning, 2007 1250-2500
Light interception radiation intercepted*m-2Energy use efficiencyLAICanopy size m³Total aerial biomass kg*ha-1Root system development kg*ha-1
m³*plantSeed yield (dry seed) kg*ha-1HI-seedWater uptake mm*ha-1PET, AET mm*ha-1*day-1Water use efficiencyNutrient uptake (NPK) kg*ha-1*yr-1 existing data Jongschaap (personal comm.)Plant potential lifespan yearsInteractions with neighbour plants Effects
Intercroppingplants*ha-1
Light interceptionEnergy use efficiencyLAICanopy size m³Total aerial biomass kg*ha-1Root system development kg*ha-1
m³*plantSeed yield (dry seed) kg*ha-1HI-seedWater uptake mm*ha-1PET, AET mm*ha-1*day-1Water use efficiencyNutrient uptake (NPK) kg*ha-1*yr-1 existing data Jongschaap (personal comm.)Plant potential lifespan yearsInteractions with neighbour plants Effects
Living fenceplants*ha-1
Light interceptionEnergy use efficiencyLAICanopy size m³Total aerial biomass kg*ha-1Root system development kg*ha-1
m³*plantSeed yield (dry seed) kg*ha-1HI-seedWater uptake mm*ha-1PET, AET mm*ha-1*day-1Water use efficiencyNutrient uptake (NPK) kg*ha-1*yr-1 existing data Jongschaap (personal comm.)Plant potential lifespan yearsInteractions with neighbour plants Effects
Plant density (a)
Plant density (a)
Plant density (a)
Annex 1c. Sustainability indicators by sphere of interest
Sustainability indicators Unit or evaluating pm Measu rement Literature ResearchCrop energy balance (input:output) 1:4-5 Henning, 2007 in Belize
AGRONOMICSoil
Structure macro-aggr stab. + 6-30% Chaudhary et al., 2007soil bulk density - 20% Ogunwole et al., 2007
OM contentMicrobial activityMicrobial diversitySoil moisture retention increased Kumar and Sharma, 2008Erosion controlOn farm use of by-products yes/no yesNutrient cycles (NPK) kg*ha-1*yr-1 Jongschaap (personal comm.)
WaterPlant water use efficiency (seeds) kg*m-3 0.615-1.314 Abdrabbo and Atta, 2008Plant water use efficiency (oil) kg*m-3 0.154-0.393 Abdrabbo and Atta, 2008Actual water use no data Jongschaap et al., 2007Water pollutionNutrient cycles
AirNutrient cycles
ENVIRONMENTALSoil
Soil recovery Spaan et al., 2004; Kumar et al., 2008)Soil preservation Spaan et al., 2004Biodiversity (macro/micro-flora/fauna) # species*m²Acidification g SO4²--eq*ha-1*yr-1 no data IFEU Institute, 2008
WaterWater consumption l*week-1*plant-1 Abdrabbo and Atta, 2008Groundwater leaching g NO3-*ha-1*yr-1Eutrophication g P2O5-eq*ha-1*yr-1 no data IFEU Institute, 2008
AirGHG emission kg CO2-eq 56,7 Prueksakorn and Gheewala, 2006GHG emission balance neutralCarbon sequestration g CO2*ha-1*yr-1
ECONOMICLabour cost $*man-1*d-1 10-15USDIncome generation $*kg-1By-products $*kg-1Fossil fuel independence $Renewable energy production $*J-1
SOCIALDiversify agr. activity # agr. activitiesLabour generation man*day-1*ha-1
Annex 1d. Sustainability indicators by crop system
CROP SYSTEMSustainability indicators Unit or evaluating pm Measu rement Literature Research
Monoculture in BelizeEnergy Input l of petrol*ha-1
Output eq-l of petrol*ha-1Water Input (irrigation) mm*ha-1*yr-1
Consumption mm*ha-1*yr-1Nutrient Nutrient input (NPK, …) kg*ha-1*yr-1
Nutrient Removed kg*ha-1*yr-1 existing data Jongschaap (personal comm.)Others Foreign molecules input (ie:pesticide) kg*ha-1*yr-1
Amendments input kg*ha-1*yr-1On farm use of by-products from JC PS kg*ha-1*yr-1Labour input man*day-1*ha-1Interactions with neighbour plants Effects
IntercroppingEnergy Input l of petrol*ha-1
Output eq-l of petrol*ha-1Water Input (irrigation) mm*ha-1*yr-1
Consumption mm*ha-1*yr-1Nutrient Nutrient input (NPK, …) kg*ha-1*yr-1
Nutrient Removed kg*ha-1*yr-1 existing data Jongschaap (personal comm.)Others Foreign molecules input (ie:pesticide) kg*ha-1*yr-1
Amendments input kg*ha-1*yr-1On farm use of by-products from JC PS kg*ha-1*yr-1Labour input man*day-1*ha-1Interactions with neighbour plants Effects
Living fenceEnergy Input l of petrol*ha-1
Output eq-l of petrol*ha-1Water Input (irrigation) mm*ha-1*yr-1
Consumption mm*ha-1*yr-1Nutrient Nutrient input (NPK, …) kg*ha-1*yr-1
Nutrient Removed kg*ha-1*yr-1 existing data Jongschaap (personal comm.)Others Foreign molecules input (ie:pesticide) kg*ha-1*yr-1
Amendments input kg*ha-1*yr-1On farm use of by-products from JC PS kg*ha-1*yr-1Labour input man*day-1*ha-1Interactions with neighbour plants Effects
Annex 2. Experimental designs
Table a. Maya Ranch trial yield design.
A B C D E F G HNot pruned o o o o o o o o 1
o o o o o o o o 2o o o o o o o o 3o o o o o o o o 4o o o o o o o o 5o o o o o o o o 6o o o o o o o o 7o o o o o o o o 8o o o o o o o o 9o o o o o o o o 10o o o o o o o o 11o o o o o o o o 12o o o o o o o o 13o o o o o o o o 14o o o o o o o o 15o o o o o o o o 16o o o o o o o o 17o o o o o o o o 18o o o o o o o o 19o o o o o o o o 20o o o o o o o o 21o o o o o o o o 22o o o o o o o o 23o o o o o o o o 24o o o o o o o o 25o o o o o o o o 26o o o o o o o 27o o o o o o o 28o o o o o o o 29o o o o o o o 30o o o o o o o 31o o o o o o o 32o o o o o o o 33o o o o o o 34o o o o o o 35
o o o o o 36o o o 37o o o 38
Pruned o o o o o o o o 39o o o o o o o o 40o o o o o o o o 41o o o o o o o o 42o o o o o o o o 43o o o o o o o o 44o o o o o o o o 45o o o o o o o o 46o o o o o o o o 47o o o o o o o o 48o o o o o o o o 49o o o o o o o o 50o o o o o o o o 51o o o o o o o o 52o o o o o o o o 53o o o o o o o o 54o o o o o o o o 55o o o o o o o o 56o o o o o o o o 57o o o o o o o o 58o o o o o 59
Not yielding o o o o o 60o o o 61o o o 62o o o 63o o o 64o o o 65
o o 66
Table b. Maya Ranch trial LAI design
A B C D E F G H1
Block 1 2 Not pruned,3 Monoculture
Not pruned, 456789
10111213
Block 2 141516171819202122232425
Block 3 2627282930313233343536373839
Block 1 4041
Pruned, 4243444546
Block 2 47484950515253
Block 3 54555657585960616263646566
o o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o o
Intercropping o o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o oo o o o o o oo o o o o o oo o o o o o oo o o o o o oo o o o o o oo o o o o o oo o o o o oo o o o o o
o o o o oo o oo o o
o o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o o
Intercropping o o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o oo o o o oo o oo o oo o oo o oo o o
o o
7 6 5 4 3 2 CA 7 6 5 4 3 2 GA53 57 55 52 51 52 50 51 49 51 46 48 45 38
o o o
oo
oo o
oo o
o oo o o o
o o o oo o o o o
o o o o oo o o o o o o
o o o o oo o o o o o o o o
o o o o o o o oo o o o o o o o o o
o o o o o o o oo o o o o o o o
o o o o o o o o o o o oo o o o o o o o o o o oo o o o o o o o o o o o
o o o o o o o o o o o o o oo o o o o o o o o o o o o
o o o o o o o o o o o o o oo o o o o o o o o o o o o oo o o o o o o o o o o o o oo o o o o o o o o o o o oo o o o o o o o o o o o o oo o o o o o o o o o o o oo o o o o o o o o o o o o oo o o o o o o o o o o o o oo o o o o o o o o o o o o oo o o o o o o o o o o o o oo o o o o o o o o o o o o oo o o o o o o o o o o o o oo o o o o o o o o o o o o oo o o o o o o o o o o o o oo o o o o o o o o o o o o oo o o o o o o o o o o o o oo o o o o o o o o o o o o oo o o o o o o o o o o o o oo o o o o o o o o o o o o oo o o o o o o o o o o o o oo o o o o o o o o o o o o oo o o o o o o o o o o o o oo o o o o o o o o o o o o oo o o o o o o o o o o o oo o o o o o o o o o o o oo o o o o o o o o o o o oo o o o o o o o o o o o oo o o o o o o o o o o o oo o o o o o o o o o o o oo o o o o o o o o o o oo o o o o o o o o o oo o o o o o o o o o oo o o o o o o o o o oo o o o o o o o o o oo o o o o o o o o oo o o o o o o o oo o o o o o o o oo o o o o o o o oo o o o o o oo o o o o o o oo o o o o o oo o o o o o oo o o o o o oo o o o o oo o o o oo o o o oo o o o oo o o oo o oo o oo oo o
o
Table c. Warrie Head trial design
4 3 2 GB 4 3 2 CB95 98 99 99 94 98 100 95
GB: Guatemala,4*1mCB: Cuba, 4*1mCA: Cuba, (3*1,7)*1,7mGA: Guatemala, ( 3*1,7)*1,7
o
o oo o
o o oo o
o o oo o o o
o o oo o o
o oo o o o
o o o o o oo o o o o
o o o o oo o o o o oo o o oo o o o o
o o o o oo o o o
o o o o o o oo o o o o o oo o o o o o o o
o o o o oo o o o o o o
o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o oo o o o o o o o
o o o o o o oo o o o o o o oo o o o o o oo o o o o o oo o o o o o o oo o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o oo o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o oo o o o o o oo o o o o o oo o o o o oo o o o o oo o o o o oo o o o oo o o o oo o o o oo o o oo o o oo o o oo o oo o oo o oo oo oo oo
Table d. Central Farm trial design (1/2)
ERA-ARD Biofuels in Africa and Central America 2009 -2013 – Planting Plan 26 November 2009Gradient >>>
Block I Block II Block III
01 o o o o o o 02 o o o o o o 13 o o o o o o 14 o o o 25 o o o o o o 26 o o o 01
o o a o b o o o o a o b o o o o a o b o o o a b o o o a o b o o o a b o
o o c o d o o o o c o d o o o o c o d o o o c d o o o c o d o o o c d o
o o e o f o o o o e o f o o o o e o f o o o e f o o o e o f o o o e f o 02
o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o
03 o o o o o o 04 o o o 15 o o o o o o 16 o o o 27 o o o o o o 28 o o o o o o 03
o o a o b o o o a b o o o a o b o o o a b o o o a o b o o o o a o b o o
o o c o d o o o c d o o o c o d o o o c d o o o c o d o o o o c o d o o
o o e o f o o o e f o o o e o f o o o e f o o o e o f o o o o e o f o o 04
o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o
05 o o o 06 o o o o o o 17 o o o 18 o o o 29 o o o o o o 30 o o o 05
o a b o o o a o b o o o a b o o a b o o o a o b o o o a b o
o c d o o o c o d o o o c d o o c d o o o c o d o o o c d o
o e f o o o e o f o o o e f o o e f o o o e o f o o o e f o 06
o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o
07 o o o o o o 08 o o o 19 o o o o o o 20 o o o o o o 31 o o o o o o 32 o o o 07
o o a o b o o o a b o o o a o b o o o o a o b o o o o a o b o o o a b o 111m
o o c o d o o o c d o o o c o d o o o o c o d o o o o c o d o o o c d o
o o e o f o o o e f o o o e o f o o o o e o f o o o o e o f o o o e f o 08
o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o
09 o o o o o o 10 o o o 21 o o o 22 o o o 33 o o o 34 o o o 09
o o a o b o o o a b o o a b o o a b o o a b o o a b o
o o c o d o o o c d o o c d o o c d o o c d o o c d o
o o e o f o o o e f o o e f o o e f o o e f o o e f o 10
o o o o o o o o o o o o o o o o o o o o o o o o o o o
11 o o o 12 o o o 23 o o o o o o 24 o o o o o o 35 o o o o o o 36 o o o 11
o a b o o a b o o o a o b o o o o a o b o o o o a o b o o o a b o
o c d o o c d o o o c o d o o o o c o d o o o o c o d o o o c d o
o e f o o e f o o o e o f o o o o e o f o o o o e o f o o o e f o 12
o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o
24 23 22 21 20 19 18 17 16 15 14 13
52m
Table e. Central Farm trial design (2/2)
Row D1 D2
G1 Mexico accession 3,7 2,2 1,1 m I1 No Intercropping Intercrop: Arachis pintoii
G2 Belize accession 3,7 2,2 1,1 m Jatropha curcas O Border row plant
G3 Guatemala accession 3,7 2,2 1,1 m I2 Intercropping X Monitoring plant
1250 2500 trees ha-1
Treatments G D I Treatment randomization plots
1 1 1 1 11 3 12 5 8 2
2 1 1 2 7 5 11 1 12 4
3 1 2 1 2 8 9 6 7 10
4 1 2 2 12 1 3 4 11 6
5 2 1 1 4 6 2 10 5 1
6 2 1 2 9 10 8 7 3 9
7 2 2 1
8 2 2 2 Treatment randomization horizontal hedge (left to r ight)
9 3 1 1 1 8 12 6 4 7 3 9 11 5 2 10
10 3 1 2
11 3 2 1 Treatment randomization horizontal hedge (top to bo ttom)
12 3 2 2 1 6 10 8 4 7 11 2 12 5 3 9
Plots row plants plants plot-1 Plants for plots Field size (m2) 6440 m2
Plants per plot D1 5 4 20 18 plots x 20 plants 360
D2 5 7 35 18 plots x 35 plants 630 990 plants
Living fence D1 D2 Plants per fence Plants per treatment unit in fence
Field length 111 m 0,25 0,50 m 55,5 m / 0.25 + 55,5 m / 0.5 = 333 D1 37
Field width 52 m 0,25 0,50 m 26 m / 0.25 + 26 m / 0.5 = 156 489 plants D2 19
Distance fence from other plots Total plants 1479 plants
At least 3,7 m
Additional plants: 255
19m
103,6m o o o o o o o o o o o o o o o
o o o o o o o o o o o o o o o
o o o o o o o o o o o o o o o
o o o o o o o o o o o o o o
o o o o o o o o o o o o o o o
o o o o o o o o o o o o o o
o o o o o o o o o o o o o o
o o o o o o o o o o o o o o
o o o o o o o
o o o o o o o
o o o o o o o
o o o o o o o
o o o o o o
o o o o o o
o o o o o o
o o o o o o
o o o o o o
o o o o o o o o o o o
o o o o o o o o o o
o o o o o o o o o o
o o o o o o o o o
o o o o o o o o o
o o o o o o o o o
o o o o o
o o o o o
o o o o o
o o o o
103,6m o o o o9m
Table f. Extra land (above and right) for additional plants atCentral Farm
Additional plants: 240
o o o o o o o o o o o o o o o o o o o o o o o o o o o
o o o o o o o o o o o o o o o o o o o o o o o o o o o
o o o o o o o o o o o o o o o o o o o o o o o o o o o
o o o o o o o o o o o o o o o o o o o o o o o o o o o 38m
o o o o o o o o o o o o o o o o o o o o o o o o o o o
o o o o o o o o o o o o o o o o o o o o o
o o o o o o o o o o o o o o o o o o o o o
o o o o o o o o o o o o o o o o o o o o o
o o o o o o o o o o o o o o o o o o o o o
o o o o o o o o o o o o o o o o o o o o o
38 m
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If you use information from this M.Sc. dissertation document, please citeand refer to:
da Schio, B., 2010. Jatropha curcas L., a potential bioenergy crop. On fieldresearch in Belize. M.Sc. dissertation. Padua University, Italy and Wageningen University and Research centre, Plant ResearchInternational, the Netherlands.