Department of Agriculture. Victoria

Internal report series no. 70 May, 1985

Agdex 243/23

The lrymple Trellis System - A Mechanized System of

Dried Sultana Production

K Leamon J Arnold

I Cook I Gould

J Whiting

('

THE IRYMPLE TRELLIS SYSTEM -

A MECHANIZED SYSTEM OF DRIED SULTANA PRODUCTION

KEITH LEAMON

JOHN ARNOLD

IAN COOK

IAN GOULD

JOHN WHITING

THE IRYMPLE TRELLIS SYSTEM -

A MECHANIZED SYSTEM OF DRIED SULTANA PRODUCTION

A WORKING PARTY REPORT TO THE MILDURA DISTRICT

HORTICULTURAL CONSULTATIVE COMMITTEE INVESTIGATING

THE DEVELOPMENT , EVALUATION AND ADOPTION OF

MECHANIZED SYSTEMS OF DRIED VINE FRUIT PRODUCTION

PARTICULARLY THE IRYMPLE TRELLIS SYSTEM

KEITH LEAMON (CONVENOR)

JOHN ARNOLD

IAN COOK

IAN GOULD

JOHN WHITING

- DISTRICT EXTENSION OFF I CER DEPARTMENT OF AGRICULTURE MILDURA

- DRI ED VINE FRUIT GROWER MER BE IN

- DRIED VINK FRUIT GROWER RED CLI FFS

- AGRICULTURAL ENGINEERING AGRI CULTURAL ENGINEERING CENTR-E , WERRIBEE

- RESEARCH OFFICER SUNRAYSIA HORTICULTURAL -RESEARCH INSTITUTE IR YMPLE

ABSTRACT

The progress of research on the Irymple Trellis System

of mechanized dried vine fruit production has been

reviewed, its future potential assessed , and factors

affecting its adoption identified.

The concepts of the Irymple Trellis System are based on

sound, well researched principles and the system clearly

has the potential to improve the efficiency of dried vine

fruit production. Many of the principles used in designing

the system have been successfully demonstrated. The

performance of the mechanical harvester has been satisfactory ,

and development of the pruning and spraying functions of

the multi-purpose machine should continue.

The use of grafted v i n es on the trellis structure has the

potential to produce lar ge crops of fruit in a configuration

ideally suited for trellis drying and mechanical harvesting .

However, the trellis has a high capital cost , and further

work on trellis design is required to achieve the optimum

structural integrity at minimum cost . Economic analyses

show the Irymple Trel l is System to be superior to the best

conventional system, but a high peak debt could limit the

rate of adoption in the current depressed state of the

industry . Various options for overcoming this proble m are

discussed . The project also provides spin - off results of

immediate benefit to th e Industry.

The working party recognizes the need for efficient

production of hi g h quality fruit, and recommend that the

current project be completed as liste d in the strategy plan

for further work on mechanization of dried vine fruit

production .

2.

3 .

4 .

5 .

6 .

7 .

INDEX

Page No .

Introduction l

Review , progress and future of the I . T . S . project 1

2 . 1 Background to the I . T . S . 2

2 . 2 Development of I . T . S . 2

2 .3 Swin g - Arm trellis 3

2 .4 Application of I . T . S . 3

2 . 5 Background of machine and trellis development 4

2 . 6 Harvester performance 6

2 . 7 Trellis design 8

2 . 8 Future engineering work 9

2 .9 Economic evaluation of I . T . S . 9

2.10 Future potential of I.T . S . 10

Eco nomi c conditions confronting the dried vine fruit industry

Adoption of the Irymple Trellis System

4.1

4 . 2

4 . 3

Limitations to adoption

Considerations re gro wer adoption

Alternative strategies available to dried vine fruit growers

,

Strategy for further dried vine fruit mechanization work

Research and extension p rioriti es

6 . 1 6 . 2

Research

Extension

Literature cited

Appendix 1

Appendix 2

Appendix 3

11

12

12

13

13

14

15

15

15

16

17

23

28

INTRODUCTION

This report is prepared by a wo rking group formed to review and def ine guide l ines for further development of the Irymple Trellis System (I . T . S . ) project being carried out at the Sun raysia Horticultural Research Institute , Irymple , and to consider the potent ial of mechanizing alternative production systems . The working group consists of two gro wer representati ves , one extension representative and the project leader and eng ineer involved in the research project .

Guidelines for the working party were set by the dried vine fruit sub - committee of the Mildura and Distric t Horticultural Consultative Committee (M . D . H . C . C . ) and were as follows:

(a) Re v i ew progress of the pro ject , results to date and likely future results .

(b) Det erm1ne the economic conditions likely to confront the dried vine fruit industry over the lo n ger te r m.

(c) Examine prospects for adoption of a successfully develop ed system .

(d) Out line a strategy for work on mechanization of dried vine fruit (DVF) in general establishing the relative impo rtanc e of the I . T . S . in relat i on to other possible syst em s .

(e) Est abli sh appropriate re search and extens i on pr i oriti es .

The completed report was submi tted t o the sub - committee ' s meeting of 13th September , 1984 , and a ccept ed with minor modification .

2. RE VI EW , PROGRESS AND FUTURE OF THE I . T . S . PROJECT

The bas is of this working g roup ' s report is the research project being conducted at th e S . H.R . I. The objective o f the project i s to develop and evaluate a vineyard management system fo r dried vine f r uit production based on the I rymp le Trellis concept and a low- cost , multi -purpose harvesting/pruning machine . The tota~ concept incorporates modern physiological principles and cultural practices in order to maximise productivity whilst also providing for the eco nomies assoc i ated with mechanization . The features of the project are to evaluate a high yieldin~ method of training and mana g ing Sultana grapevines (the Irymple Trellis System) and at the same time developinp a re lat ively s imple met h od of mechanization to harvest - prune , spray and harvest t he f rui t using the one specialised machine unit . The overall aim is to increase the efficiency of production of dried Sultanas .

1

2.1 Background to the I.T . S.

The traditional method of pro~ucing dried Sultanas is based on hand pruning and harvesting techniques. Labour input accounts for about 46 per cent of the total operating costs of a vineyard and about 65 per cent of the labour is involved in pruning and harvesting operations (Witcombe, 1983). Mechanization is one method of imp roving the efficiency of production by reducing the high cost of labour for harvesting and pruning. It also allows the labour to be employed in other aspects of dried fruit production, for example in the propagation of vines grafted onto nematode rootstocks. Production costs within the wine grape sector of the Australian viticultural industry have been substantially reduced by the substitution of mechanization for the labour involved in pruning and harvesting.

However, specific features of dried Sultana production, namely the necessity to harvest the

2

fruit in an undamaged condition and the unsuitability of the Sultana vine to conventional spur pruning, impose restraints on the mechanization of dried Sultana production which are n o t present in the production of wine gr~pes. Consequently, developments in the mechanization of dried Sultana production have been relatively ~ ~low.

2.2 Development of I.T . S.

The Irymple Trellis System of dried Sultana production was developed in 1976 at the Sunraysia Horticultural Research Institute . A trellis was constructed in that year on a planting of own ­rooted Sultana vines and observations on a limited basis were made up to 1979. Further conceptual development of the system took place during this period and the operation of the Irymple Trellis System has been described (James 1978, 1979) , (See also Appendix 1). Early results over three seasons showed that vines trained to the Irymple Trellis yielded approximately 32 per cent more grapes than adjacent vines trained to a 0.9 m wide T trellis. By 1979 the Irymple Trellis had been established to cover three rows of approximately 40 vines per row. A trial was then established to assess the effect of harvest pruning (an integral part of the Irymple Trellis System) on dried fruit production. Over three seasons vines trained to the Irymple Trellis System outyielded the traditional single wire trellis system by about 72 per cent. The increase in yield was mainly due to more clusters per vine which in turn was caused by more nodes being retained on the I.T.S. vines.

Differences in berry weight and berry numbe r per cluster were much smal ler and on average the concentration of tot al soluble solids was reduced by about 1° Brix . Howe ver , harvest pruning reduced overall yields by about 12 per cen t , a level similar to that reported in other expe ri ments with Sultana (May and Scho lfield , 1972). Despite this, harvest pruned I . T . S. vines y i elded 50 per cent better than non - harvest pruned s in gle wire trellis vines.

2 . 3 Swin g - Arm Trellis

At about the same time as the I . T . S . was be i ng developed a similar trell i s design was bei n g evaluated by the C. S . I . R . O., Divis i on of Ho r ti ­cultural Research at Merbein and by the Ne w South Wales Department of Agriculture at Dareton . The C. S . I . R . O. have reported a 31 per cent inc r e ase i n fresh yield wit h the ir s wing - a r m t rellis i n comparison with a single wi re trellis when simila r numbers of canes were retained on both treatments (Cl i n ge leffer and May , 1981). At Dareton , early r esults i ndicate that Sultana vines grafted to the rootstocks Ramsey and Dog Ridge r espond bet te r to the swing - arm trellis than own - roo t ed vines. Vines grafted to Ramsey and Dog Ridge are produci n g about 12 per cent and 31 per cent better in comparison with g rafted v i nes trained to a wide T trellis. However , ne i ther of t hese g roups is evaluating the trellis as part of a complete system of management incorporating the principles of mechanical pruning and harvesting.

2 . 4 Application of I . T . S .

With the initial plantings the application of mechanical pruning and harvesting could only be demonstrated in principle. Thus it was successfully demonstrated that a cutter bar could be used to harvest prune in a stra i gh t line a l ong the row , the fruit could be sprayed with oil - emulsion to enhance drying and beati n g the trellis arm could remove the dried fruit. A multi - purpose machine has subsequently been developed to perform these functions (see Part 2 . 5) .

Several potential problems relating to hort i cultural aspects have been observed . In some cases the repl acement ca n es do not attach to the raised trellis wires. A moveable foliage wire has success ­fully overcome this problem and other methods are being evaluated . Fresh clusters of grapes along the central cordon may ge t harvested with the dr ied fruit and hence should be hand picked before mechanica l harvesting or r emoved at an earl y stage of the season .

Some chemical sprays are effec~ive in inducing abscission of clusters and these are being evaluated for practical use of the I.T.S.

The management of the central cordon has also posed a potential problem . Despite some die -back of the cordon and spurs the I . T . S . vines are still producing more than adequate numbers of canes after eight years. If a problem does arise in the longer term then it seems likely that old cordons could be removed and a new replacement cordon system developed . The loss of vigour and yield due to repeated harvest pruning is another potential problem. It is cl ear that the I .T. S . ~ ~ will not overcome the effects of harvest pruning but the use of vigorous rootstocks may compensate for the loss of vigour and yield associate d with own -rooted vines.

Another important aspect is quality of the dried fruit . The delay in maturity on the I.T.S . means that d ryin g time is shortened and the fruit is more susceptible to browning which occurs when partly dried fruit is wet by rain. This problem has not been overcome but it is being examined through methods of enhancing ripenin g , development of an efficient cluster wetting syst em and assess ­ment of chemicals for anti - ox i dant properties.

2.5 Background to Machine and Trellis Development

4

The main objective behind the development of the multi - purpose machine system for the Irymple Trellis System were:

a small low cost machine, which could be ' scaled up ' for use by larger operators ,

low power requirement, simple design ,

to incorporate exis ting machine sub -assemblies whic h are readily available to reduce production costs and aid commercial adoption ,

high manoeuvrability in the vineyard,

one man operation with high field efficiency .

The basis of machine des i gn is to load fruit directly into conventional bulk bins (500 kg) held inside the chassis of the machine . In operation the bins would be filled in situ by the machine and then unloaded at the headland, at which time empty bins are loaded. The two or more bins held by the machine would ensure that the machine had ade~uate capac ity to complete a row without having to travel to the end of a row to collect bins, ensuring high field efficiency .

This system also means that travelling down a row to collect full, or deliver empty bins, is not necessary . Furthermore, if adequate bins are placed on the headland at the start of the day, and full bins collected at the end of a day , harvesting would be a truly 'one man ' operation as 'back up ' staff would not be required.

Fruit is removed ·from the horizontal canopy by fingers beatin g from the top of the canopy. The f r uit is collected from beneath the canopy and carried by belt conveyors to the back of the machine and elevated to a belt above the bins by a cleated conveyor . Fruit passes under a trash r emoval fan as it passes to the delivery be lt. S i mple 'diversion bars ' guide fruit from the d e livery belt into the desired bin . The bin filling sequence starts from the front of the machi ne .

Full bins are unl o aded, and empty bins collected by a powered bin pick- up and roller system, operated from the operator ' s platform.

Adoption of a trellis layout in which the fruit bearing canopy of two adjacent rows face the same in ter-row space enab les t h e ' one - sided ' basic machine unit to be developed into a machine with doubled capacity . A ' do uble-sided' machine based on the same machine sub-assemblies and greater bin holdin g capacity will allow harvest of two ad jacent rows simultaneously , requiring travel down only every second row . Similar principles operate

5

for the machines harvest pruning and spray application functions . This design i s the way chosen to allow development of a machine s yste m to suit b ot h smaller or lar ge r family vineyards .

Objective design of the tre ll is structure is essential to ensure that a cost effective design is developed. Structural analysis of trellising for v i t i cultur al crops is an area of study not widely reported on in the li te rature . Consequently , this aspect of the project will become a major work area in the coming years. Also, muc h of what i s found in trellis desi gn wi ll have dire ct application to other trellis forms.

A tre ll is structure is made up of four ma in components:

( i ) ( i i )

( iii ) (iv)

th e c rop support wires trellis arms (including ~eta i ls of fixing

to t h e po.st) intermediate posts trellis end ass emb lie s

The function and load carried by each component must be considered and a cost effective design developed. Costing of the tFellis must include costs of trellis materials and installation costs .

A program for the development of the machine and testing of trellis systems has been proposed and is as follows:

(a) Develop basic layout and operating principles for multi - purpose fr uit harvester , pruner and spray application machine .

6

(b) Develop a detailed design for St a ge l of the machine, the self- powered chassis and harvesting components.

(c) Machine construction to Stage l , and field trial.

(d) Stage 2 of machine development . Refinement of the harvesting functions and design and construction of the mechanized pruning system .

(e) Res e arch function a n d loads exerted on a ll trellis structure compon ents (wire, trellis arms, intermediate posts an d end assemblies) and develop an appropriate design.

( f) Stage 3 of machine development . of automated pruner .

Refinement

(g) Research , in conjunction wi th expert Depart ­mental staff , the most appropriate me thods of spray appl icati o n .

(h) Stage 4 - detai led design and construction of the spray application function of the mul ti­purpose func tion machi ne .

At this stage Items l, 2 and 3 have been c omplet ed , Items 4 , 5 and 7 are currently bein g undertaken and Items 6 and 8 wi ll be covered in future .

2 . 6 Harves ter Performance

Limited field trials co n ducted in March 1983, indicate d t h at a few p r oblems existe d with the harvester . The major conce rn was with an e xcess i ve amount of dried canes whi ch were beaten through the trellis wires and o bs t ructed the flo w of fruit on the collection and transver se conveyors . Fruit removal wa s not a problem , with th e e xcep tion of some f ruit close to the cor don, even though th e season wa s plagued by we t weather and the fruit was generally regarded as being " tough " to remo ve . Modifi ca tions to th e beater fin ge rs were subsequently made so that the canes were not pushed through the crop supp ort wires, thus reducin g the problem considerably .

During the 1984 harvest a replicated trial of eight groups of three panels (3 vines per panel) were harvested with the machine in late March and early April. Fruit delivered to the bin was weighed as was the fruit left on the vine . Hessian sheets were placed on the ground to retrieve fruit which was not collected by the machine. After removal of leaves, canes and other trash, the remaining fruit was weighed. For five of the three panel sets a stop-watch was used to record harvest time.

TABLE 1 - 1284 Harvester Performance

Proportion Standard of Crop % Deviation

Fruit Removed 89 . 4 6 . 5

Collected by Harvester 76 . 8 10 . 4

Fruit

Fruit

on Ground 12.6 4. 9 not Removed 10 . 6 6. 5

Harvester performance for the 1984 season is shown in Table 1 . The machine failed to collect 12.6 per cent of the harvested fruit with individual replicates ranging from 6.9 per cent to 23.3 per cent . The losses during collection were due to a combination of inaccurate machine placement along the row , and deficiencies in the design of the fish - plate closures around the vine trunk. Modifications proposed will improve the fish - plate design and allow more accurate machine placement down the row. No significant fruit lo&s was detected from the trash removal fan.

Fruit removal was variable and ranged from 75 . 9 per cent to 97 . 6 per cent and averaged 89.4 per cent . Several factors contributed to the lack of complete fruit removal. Fruit lying either side of the trellis arm initially was not removed, however, improved operator skill in controlling the height of the beater head over the arm showed that complete removal could be achieved. On a few occasions, canes bearing fruit were missed in the manual cutting. In such cases dried fruit close to the clusters of fresh fruit were not readily removed.

Mechanized harvest pruning must be arranged so that no canes are missed . Fruit laying across a cordon was not readily removed by the beater as the shock impulse was not transmitted to remove such fruit. Further development of the beat e r will proceed.

7

The most significant factor reducing fruit removal was non-uniform sag between the four crop support wires. Uniform sag between trellis arms across all wires does not reduce fruit removal as the operator can adjust the beater head as the machine proceeds do wn the row. However , if in particular , the centre two wires sa g further than either of the outer two wires than fruit hanging on those

8

wires is not readily removed. Correct pre - tensioning of trellis wires during winter is expected to solve this problem.

The times taken to harvest fruit during the 1984 trials in~icated a harvest speed of 0 . 44 km/hour. The actual crop yield was 9 . 1 tonne/ha (dried wt . ) which imp l ies a harvest rate of 1 . 25 tonne/hour. It is fully expected that improvements to the machi ne and more experienced operators wi ll enable the harvest rate to substantially increase .

2.7 Trellis Design

The cost o f materials and erecti on of the trellis structure for the I rymple Trellis Sy stem is a substantial additional cost over conventional trellis systems. The integrity of the structure is clearly important as a major failure could result in the crop being dropped to the g round r esultin g in crop loss and vine damage , while a mi nor failure could mean wire sag to such a degree that the harvester could not fit under the crop.

Design of the trell is structure is best considered in terms of its four main components , crop support and training wires , trel l is arms (including details of fix ing to posts),intermediate posts and trellis end assemblies . Stati c loads due to the foliage , canes and crop need to be considered , as wel l as dynamic loads caused by wind and /or rain storms , overhead ir ri gatio n and machine harvesters .

To date preliminary wire tension dat a has been collected using equipment developed by Young (1980) for the mid - span of some panels fitted with 2 . 5 mm diameter H. T . wire. The mean of all loads measured was 1.3 kN, with the highest loads being re cor ded consistently on the third wire out from the co rdon , where the mean load was 1 . 7 kN . A peak tension of 1 . 9 kN has been recorded . Further work is required to understand the nature of lo ads on the trellis structure and the n to be able to specify a cost effective des i gn .

2.8 Future Engineering Work

It is anticipated that the modifications to improve fruit collection and increase fruit removal will be made for the 1985 harvest. The pruner, has been constructed at the A. E . C. Workshop/Test Facility, and will be mounted on the harvester in time for use on the 1985 crop. It is hoped a simple system for the cutter bar to "jump" trellis arms will be developed.

Research on the trellis structure is a longer term exercise and should proceed th i s year. Economic analysis has shown the who le system to be sensiti~e to trellis costs, therefore we must ensure a cost effective design. An inadequate trell is design may fail dramatically !

2.9 Economic Evaluation of I . T.S .

A preliminary economic analysis of the Irymple Tr ellis System has been carried out and is presented in full in Appendix 2 . This analysis demonstrated the g reat er profitability of the system as reflect ed in the higher annual cash surplus but there are major difficulties in financing the project becaus e of a very high peak ~ebt .

However , it should be pointed out that r e planting with roo tstocks onto a wide T trellis (the other comparison in the analysis) also produced a high peak debt beyond the ability of most growers . The major cost of the I .T. S . was the trellis system and further design work wi ll look a t increasing the cost efficiency of the trell is . Redevelopment to the I . T . S. is probably only feasible where the r edevelopment rate is low, where a grower has the capacity to finance a large proportion of the debt or where a grower has an o utside source of income .

Other option s for redevelopment to the I . T.S . were also investi gated (Appendix 3) . Sp reading the cost of the trel lis by delaying the i nstallat ion of the trellis arms until year 3 reduces the peak debt. If the installation of the trel l is had been delayed fur t he r and ~he system operated as hang ing cane, the trellis arms could be installed o nc e a net cash surplus occurs . Using the hi ghe r yield figures being achie ·~ed at Dar e ton does not change the peak debt very much but the long term profitability is certainly greater .

9

2 . 10 Futur e Potential of I . T . S .

Much of the work so far has been conducted on own­rooted Sultana v ines where th e yield potential is limited to about 9 t/ha dry wei ght . Indications from the trial at Dareton suggest that with grafted vines 11 - 12 t/ha dry wei ght can be achieved. In 1982 with the financial assistance of the Rural Credits Develo pment Fund of the Reserve Bank a new planting of Sultana vines gr afted to Ramsey rootstock was made at the S.H . R . I . and the vines trained to the I . T.S . Early vine growth has been vigourous and the first crop is to be harvested in the 1985 season. Various trials have been superimposed on the planting. The se include a vine spacing trial , a trellis comparison trial with a wide T and hanging cane syst em , and the evaluation of various dried vine fruit cultivars , e . g ., Merbein Seedless , Carina , Zante and Muscat Gordo Blanco for their suitability to the system.

Other countries have also shown interest in the system. Researchers in Sout h Afr i ca are evaluating the swing - arm trellis and in California a similar concept is bein g evaluated (Studer~ a l , 1982) even to the extent that features of the S . H.R . I . multi - purpose machine wi ll be incorpora ted in machine pr ototypes (Bryant, 1982) .

In principle the Irymple Tr ellis System clearly has the potential to improve the efficiency of dried vine fruit production . In practice many o f the principles used for the hort i cultural aspects have been demonstrated and full testing of the s y stem with mechanical pruning , spraying and harvestin g is nearing realit y . However, even though hort i cultural aspects show tremendous potential , the I . T.S. ~ust be looked at as a complete system of management which is radically different to the conventional production methods . Th us acceptance of the system wi l l not only rely on horticultural aspects but also on successful development of engi n ee rin g as p ect s (trellis desi g n and machin e development) , favou r-able economic anal ysi s of the system an d the ability of g r owers to adopt the new technolo g y .

10

ll

ECONOMIC CONDITIONS CONFRONTING THE DRIED VINE FRUIT INDUS TRY

A short term future of the dried vine fruit industry appears bleak. A serious cost price squeeze will cont inue into the foreseeable future and returns from dried vine fruit will continue to be extremely poor. Opportunities to reduce costs will be fully explored and adopted by many. This will include the use of higher producing vines, and more efficient harvesting techniques and farm management practices. However, it is important that the adoption of cost saving measures should not compromise the production of quality fruit.

The long term future of the industry at this stage is very hard to predict and relies on many factors . The current I.A.C. enquiry and B. A.E . attitudes have encouraged thinkin g toward total production to change . This will also be largely influenced by Government policy . It is extremely likely that ttere will be a large reduction in the number of producers and an increase in the size of many dried vine fruit properties . Economic reality will dictate far greater efficiency and unless adopted at a rate which has previously not been realized, profitability by those remaining will not be possible and we may see the demise of the industry .

Th e sale and price of dried vine fruit will continue to be substantially influenced by wor ld production . Wit h the inc r ease in plantings particularly in the U . S . A., and the subsidies given by the E.E.C . there appears to be little chance of any major improvement in returns from export sales . Countries that produce hi gher quality fruit at a competitive price will be able to mainta in their present sales but there appears to be little chance of any large increases in sales . The reliance on poor production years to raise returns to producers appears very l imited due to improved and more widespread use of modern technology.

The following are considerations if growers are to improve viabilit y :

decrease costs, e . g ., mo r e effic ient irrigation , more mechanization, lower capital costs ,

in crease productivity - i.e. , more tonnes/ha, but less hectares in production, e.g ., rootstocks, better trellis systems, closer vine spacing,

increased total production per operator , e. g . larger properties , which would be balanced by phasing out of inefficient p ropert ies ,

diversity - i . e . , g et out o-:: dried vine fruit and into a more profitable venture ,

moye effic ient marke tin g t o promote and sell dried vine fruit in Australia and overseas .

In summary - planting and production trends indicate that world production of dried vine f ruit will increase substantially .

the E.E.C. will continue to subsidise dried vine fruit making export markets less profitable.

unless consumption (in existing market s or in new one s ) can be increased then a surplus of dried v in e fruit will continue.

12

the effect of natural crop los ses wil l decl ine as new technology develops to overcome them.

therefore, fo r growers to maintain viability they must increase the efficiency of production , and mechanization is one method of doin g this .

4. ADOPTION OF THE IRYMPLE TRELLI S SYSTEM

4.1 Limitations to Adoption

Under the present conditions adoption of the Irymple Trellis System is likely to be minimal. The main reasons appear to be:

high capital cost of trellis (see Appendix 2)

the multi -purpose machine is radically different to any others a nd development of a commercial unit would be costly

need for specialized management techniques

g rower doubts about how vines will perfo r m

difficulty in making major changes to trellis and machinery

doubts about sp e cificat i ons in constructing a minimal cost trellis of adequate st reng th

grower resistance to change

difficulty in planning for the future within financial constraints , possibly imposed by doubtful future of i ndust ry

difficulty in borrowing the amounts of money required to redevelop

i f entitlements are acce p ted by the industry then there i s no incent ive to improve pro ductivi ty unless the e rower diversifies part of his block into some other c rop.

In 2 or 3 years time the research and extension units should be in a position to work closely with any interested growers. Assistance should be provided to harvest-prune, spray and harvest the crop with the S.H.R.I . prototype machine in the early cropping years , thus providing a positive incentive and reduction in adoption costs .

It is possible that larger enterprises, where capital is available, may be interested in the ability of the system to be fu lly mechanized and th e subsequent improvement of production efficiency ,

4 . 2 Considerations re Grower Adoption

*

*

*

*

Necessary to demonstrate economic advantages , particularly in terms of labour and management time saving and yield improvements, in comparison with traditional labour intensive systems.

A 'model' block would be useful in demonstrating how the system works in practice . This should be easily available for inspection and evaluation by interested people.

Concise, easily understood technical informat ion should be readily avai lable.

All industry service groups should be aware of and understand the system , i . e ., Bankers , Packing Company Management , Government Service Departments .

4. 3 Alternative Strategies Available to Dried Vine Fruit Growers

(a ) Stay the same - no extra cost or changes necessary by grower ; easy way out; likely to be financially disastrous in the long term .

(b) Use alternative trell i s systems on existing vines - variable capital input required; range of options available (which one to use?); some short term .increases in productivity likely which may be enough to re - finance planting wi th grafted vines .

(c) Redevelop with grafted vines on existing trellises - does not require as high a capital cost as redevelopment with trellis; grafted vines likely to be too vigorous ~or old trellis systems , therefore could have fruitfulness and ripening problems ; in the longer term one would hope to refinance the trellis installation vines out of production for 3 years .

(d) Redevelop with grafted vines on a better trell i s (e . g ., wide ' T ' ) - ~ikely to be a very high cap ital input (see economic analysis Appendix 2); part of block is out of production for 3 years.

The best alternative trellis will depend on what a g rower plans to do . For hand or mechanical harvesting Marshall trellis could be used on low vigour vines or a wide T or hanging cane fo r vigorous vines.

The best option for adoption of the Irymple Trellis would be to integrate the System by inititally training the vines onto the hanging cane system and attaching the trellis arm component at some stage in the future (see Appendix 3).

14

5. STRATEGY FOR FOR FURTHER DRIED VINE FRUIT MECHANIZATION WORK

5 . l (a) Complete the Irymple Trellis System project as planned using DFRTA funding (June, 1988) .

(b) Present results to gro wers as a pac ka ge so that it can be referred to in the future when a stage is reached that it is likely to be adopted (by June , 1989) .

(c) If g rowers wish to use the Irymple Tr ell is System then ass ist ance sho u ld be directed to a few selected growers so that they may be able to take up the s y stem and provide demonstratio n blocks for other growers .

5.2 Put more work into the hanging cane system either as a system to be set up and converted to Irymple Trellis System or as a complete system that can be mechanized .

5 . 3 Research application of drying oils for trellis drying .

5.4 General engineering input needed in trellis design and mechanization of existing trellis systems .

There are a number of aspects which justify continuation of the project as planned . The potential improvements in efficiency of product i on a nd the greater profitability of the system in the long term are recognised as important factors in the survival of the dried vine fruit industry. Although adoption of the system in the near ~uture i s limited the current research program in producing spin-off results that are of immediate benefit to the industry . e . g ., information on yield limits for dried vine fruit production, chemical removal of crown bunches and assess -ment of trellis components. The option of training vines initially to th e .hangin g cane system of moderate cost and changing to the Irymple Trellis System at a later date is an attractive approach .

~. RESEARCH AND EXTENSION PRIORITIES

These priorities are based on the expected available resources and do not cover all the strategies outlined' in the previous section as the resources are not expected to be available to carry the strategies out .

6.1 Research

(a) Mount pruning head and test during 1984/85.

(b) Modifications to harvester to reduce losses off machine 1984/85 .

(c) Assess performance of grafted vines 1984/85 to 1987/88.

(d) Design and construct a spray attachment for use in 1985/86 - in conjunction with ACARU .

An approach should be made to the Frankston Spray Group (ACARU) to ensure they include spray application studies on the Irymple Trellis System canopy and fruit.

(e) Continue with viticultural aspects such as crown cluster removal usin g chemicals, improving the attachment of canes, etc.

6 . 2 Extension

(a) Continue liaison with Irymple Trellis System Group .

(b) Publish material on the concepts behind the Irymple Trellis System .

(c) Publish a review of the whole project as a package for grower reference in the future (by June, 1989).

15

7. LITERATURE CITED

Bryant, D. (1982) -California-Arizona Farm Press,

April 24, pp 17 .

Clin·geleffer, P.R. and May, P, (1981) - S . Afr. J. Enol.

Vitic. 2 : 37-44.

James, K.R. (1978) -Dept. Agric. Vic., Agric. Eng.

Interim Report No . l

-

James, K.R . (1979) - Proc. Mechanical Pruning Workshop,

Roseworthy Agricultural College, May 30-31, pp 70-78.

16

May, P and Scholefield, P.B. (1972) - Vitis l l : pp 296-302.

Studer, H.E., Olmo, H.P. and Kliewer, W.M. (1982) -

In Proceedings Grape and Wine Centennial Symposium,

University of California, Davis, 1980, pp 201-205.

Witcombe, R.K. (1983) - Government of Victoria,

Research Project Series, No~ 160

Young, G.S. (1980)- Ag ric. Eng. Aust. 1 2 pp 10-16 ,

\PPENDIX 1

A MECHNICAL SYSTEM OF DRIED SULTANA PRODUCTION

THE IRYMPLE SYSTEM

17

Approximately 65 per cent of the labour required in the production of dried Sultanas is involved in the harvesting and pruning operati ons. Production c o sts within the winegrape sector of the Australian viticultural industry have been minimized by the substitution of mechanization for the labour involved in these operations. However, specific features of dried Sultana production, namely the necessity to harvest the fru i t in an undamaged condition and the unsuitability of the Sultana vine to conventional spur pruning impose restraints on the mechanizat ion of dried Sultana production which are not present in the production of winegrapes.

At the Sunraysia Horticultural Research Institute we have conceived a system specifically for the production of dried Sultanas based on a trellis of novel design and a multi - purpose machi ne which could be readily adapted for specific cultural operations .

The main aim of the system is to separate the replacement canes fro m the fruiting canes thus allowing mechanical harvest pruning to be used without damaging the replacement canes. The concept also covers a completely integrated system of management and does not only concern the trellis.

The design of the Irymple Trellis System was based on a number of well defined principles .

(i) Replacement canes trained in a vertical direction have higher bud fruitfulness (May 1966).

( ii) Shoots have a natural tendency to climb .

( i ii) Radiation wi thi n dense grapevine canopies limits photo ­synthesis (Shaulis ~ al , 1966) and thus good leaf exposure is essent i al to maintain production .

( i v) Replacement shoots arise mainly from spurs ~t basal buds Of canes and be i ng less fruitful the number of crown clusters is low (Antcliff and Webster, 1955) .

In following these principles a number of features of the Irymple Trellis System are apparent:

* the fruitin g canes are positioned away from the replacemen t c ane s and can be harvest pruned by runnin g a c utter bar parallel to the central cordon alon g th e row.

HARVEST PRUNING FOR TRELLIS DRY ING ( Fi g . 3)

This involves cutting the fruiting canes between the ~,

central cordon an d the inner wire, which are 30 em apart. The cutter is allowed to move within this dis t ance a s it travels down the row so some sort of guida nce system will be needed .

0

c.a t b.c..+c..u~C:... +kc.,. c.erd..o.... o..~

+4.' c ..;y \ + ~·---·

Fig . 3 Cutt in g Can e s for Trellis Dry~ng

MECHANICAL HARVESTING of the dried fruit is the ne x t process (Fi g . 4)

Fi g ~ 4 Harve s ting Dried Fruit .

20

s

The ha r vester is an in - row machine wh ich has been des i gned using existing components from othe r harves t e r s. In the proto - type machine the fru i t is shaken off from ab o ve the trellis arm and conveyed to standard bulk bins for ease of handling . All operations can be perf.ormed by t h e operator without leaving the machine .

The machine has also been designed for multi - purpose functions which ultimately will include spray i ng (fungicide , oil - emulsio n ), harvest prunin g and harvesting components which are readily attachable .

P~UNING the vine is now ~ simple operation with the Irymple Trellis (Figs . 6 , 7) . The horizontal canes have been previously cut during the summer pruning/trellis drying process , so no further cutting is necessary . The dead canes are removed from the horizontal arm which

21

is then raised into the air . The opposite side is lowe r ed into the horizontal position. This arm supports the canes which will bear fruit in the comin g season . The spurs left on the replacement side will d e velop the replacement canes which will wind themselves onto the wires . It is a nticipated that some manual prunin g may be needed each year .

Jc~~ prc..u-b~ '-'"'"-·

Fi g . 6 Removing Pruned Canes

Fig . 7 A~m~ Changed oyer for next season

This completes the yearly cycle. In the next season, the horizontal arm (now the other side of the trellis) develops all the fruit and the replacement canes g row up and attach themselves to the raised side.

Progress

To date the basic machine has been built and the harvesting component fitted and tested. The mechanical pruning component is to be fitted for the 1985 harvest and the spray application part for the 1 986 harvest .

References

Antcliff, A. J. and Webster, ~l.J . (1955)- Aust. J . Agric. Res. _§_ : 565 - 588 .

May, P. (1966)- Aust. J. Agric . Res. 11.: 479 - 490 .

Shaulis, N.J., Amberg, H. and Crowe , D. (1966) - Proc. Am . Soc. Hort. Sci . ~ : 268-280.

22

APPENDIX 2 .

ECONOMIC EVALUATION OF THE IRYMPLE TRELLIS SYSTEM OF DRIED VINE FRUIT PRODUCTION

The analysis compares the economic performance of the Irymple Trellis System with the conventional wide T trellis , for two rates of redevelopment of an eight hectare Sultana planting .

Assumptions

1 . The property is presently planted to eight hectares of Sultanas , yielding 30 dried tonnes , (1.5 tonnes/acre) .

2. The property is redeveloped to either the Irymple Trellis System or the convent ional wide T trellis at one of two rates; one hectare per year and two hectares per year.

3 . The material only cos t o f both trellis in g systems are assumed to be as follows :

Irymple Trellis System

Box strai ner and stay

Intermediate post 10' pointed

Trellis arms 51 x 51 x 3 . 0 angle x 2m

Trell i s arm support (flat steel & bolts)

Wire locks for 8 wires (need 240)

Wire - l fruit wire 3.15 HT

- 7 foliage wires 2 . 5 HT

Wide T . Trell i s

Box strainer and stay

Intermediate·post 8 ' pointed

Trellis arm 30 X 30 X 3 . 0 angle X l

Trellis arm support (bolt and wire)

Wire locks - 2 wires (need 60)

Wire - 2 fruit wires 3 - 15 HT

m

$/Unit $/ha

ll. 50 ea . 345.00

7 . 08 ea . 2902 . 80

4.16/2m 1705 . 60

l. 37 ea . 561. 70

l. 55 ea . 372 . 00

0 . 0523/m 156 . 90

0 . 0426/m 896 . 07

$6940 . 07/ha

11.50 ea 345 . 00

5.46 ea . 2238.60

1 . 30/m 533 . 00

0 . 65 ea . 266 . 50

l. 55 ea . 93 . 00

0 ! 0523/m 313 . 80

$3789 . 90/ha

23

freight cost: $7 . 00/tonne.

erection tirre for the Irymple Trellis is assumed to be 500 hours per hectare . The analysis assumes that hired labour is employed for trellis erection, vine planting and training at $7.11/hour.

7 . Specific assumptions relating the conventional wide T trellis system are :

extra pruning costs for the 8 hectare property, when fully developed, of $2,500 per annum.

increase in spray material cost for the fully developed property; $400 per annum.

the crop is trellis dried and mechanically harvested from Year 5, (4 year replanting program) and from Year 6 (8 year replanting program). The capital cost of $19,000 is made up by the purchase of a mechanical harveste r $14,000 and spray plant, $5 , 000.

All harvesting, drying and freight costs are assumed to be the same , per tonne , as the Irymple Trel~is System.

erection time for the trellis is assumed to be 165 hours per hectare , and is casted in full , at the hired labour rate of $7.11 per hour .

8. The analysis ignores the effect of inflation on costs and returns over time , and takes no account of the taxation implications of the alternative systems.

The analysis makes no provision for the servicing of a loan to finance the trellising system , and makes no allowance for existing loan repayments or personal expendit u re .

25

Redevelopment to the Irymple Trellis System is probably only feasible in situations where the grower;

is prepared to redevelop at a relatively low rate ; one acre or less per year,

27

or where the grower has a block which is substantially free of debt , and the capacity to finance at least

*

50 per cent of the deficit through his own resources ,

or where the grower has an outside source of income , sufficient at least to meet all living costs.

I t may be , that with limited capital, the grower is better off in the medium term (say up to 15 to 20 years), to redevelop to the conventional trellis at say 2 acres per year, than be forced to redevelop to the Irymple Trellis System at a lower rate of only one acre per year .

In fact , the slightly higher internal rate of return values for the conventional trellis system over the Irymple Trellis System indicate, that, for the assumptions applying to this analysis, and over a 20 year period, the redevelop­ment to the conventional trellis , will give a slightly higher return on each dollar inves t ed , than redevelopment , at the same rate to the =rymple Trellis System.

Russell Witcombe senior District Extension Officer (Economics) Department of Agriculture Mildura

February 1984

... 0

> ;; ;; ! "

TABLE 1

8 Year Replanting Peri od (1 ha per year)

Wide T Wide T I.T . S . I.T . S. * I. T . S . I. T. S . Hand Mechanically Mechanically Option 1 Option 2 Option 3 Harvested Harvested Harvested

(as per R.W .)

Cumulative Cash Surplus Year 20 $133 , 000 $:n4 , ooo $388 , 000 $388 , 000 $580 , 000 $580 , 000

Annual Cash Surp lus Full Production $16 ,000 $28 , 000 $40 , 300 $40 , 300 $55 , 000 $55,000

Peak Debt $47,600 $52 , 000 $81,000 $68 , 600 $75 , 800 $63,100

Year Peak Debt 8 6 6 6 6 6

Breakeven Point 11 11 11 11 10 10