amelioration of indian urban air pollution phytotoxicity in beta vulgaris l. by modifying npk...
TRANSCRIPT
-
8/14/2019 Amelioration of Indian urban air pollution phytotoxicity in Beta vulgaris L. by modifying NPK nutrients
1/11
Amelioration of Indian urban air pollution phytotoxicity
in Beta vulgaris L. by modifying NPK nutrients
Anoop Singha, S.B. Agrawalb,*, Dheeraj Rathorea
aLaboratory of Air Pollution and Global Climatic Change, Department of Botany,
Allahabad Agricultural Institute - Deemed University, Allahabad 211 007, IndiabDepartment of Botany, Banaras Hindu University, Varanasi 221 005, India
Received 28 November 2003; accepted 17 September 2004
Air pollution caused adverse impact on growth and biomass accumulation of Beta vulgaris L. plants
while higher fertility levels showed reduced yield losses.
Abstract
Air pollution levels are increasing at an alarming rate in many developing countries, including India and causing a potential
threat to crop production. Field experiments were conducted to examine the impact of urban air pollutants on biomass (yield) and
some physiological and biochemical parameters of palak (Beta vulgaris L. var. All Green) that grew from germination to maturity at
seven periurban sites of Allahabad city having different concentrations of air pollutants under different levels of nutrients. The 6 h
daily mean NO2, SO2 and O3 concentrations varied from 2.5 to 42.5, 10.6 to 65 and 3.5 to 30.8 mg m3, respectively at different
locations. Levels of air pollution showed significant negative correlations with photosynthetic pigments, protein, ascorbic acid and
starch contents and catalase activity of palak leaves. A significant negative correlation was found for total biomass with SO2
(rZ
0.92), NO2 (rZ
0.85) and O3 (rZ
0.91) concentrations. The increased fertilizer application (N, P and K) over therecommended dose resulted in a positive response by reducing losses in photosynthetic pigments and total biomass. This study
proved that ambient air pollution of Allahabad city is influencing negatively to the growth and yield of palak plants.
2004 Elsevier Ltd. All rights reserved.
Keywords: Air pollution; Nutrients; Beta vulgaris; Biomass; Yield
1. Introduction
The impacts of air pollution have long been recognized
as major cause of losses in crop production in several
developed countries. However, little attention has beenpaid in developing countries, including India, on poten-
tial impacts of air pollution on growth and productivity.
The Indian national ambient quality data indicate that
emissions of a range of air pollutants are generally
increasing (Agrawal, 1998). The annual average of SO2
concentrations ranged from 10.4 to 39.0 mg m3 ppb in
most parts of the country, while NO2 concentrations were
found between 43.2 and 60.1 mg m3 in metropolitan
cities. Pandey et al. (1992) reported elevated concen-
trations of O3 in Varanasi city, an adjoining district ofAllahabad, where significant negative influence of urban
air pollutants was recorded on a variety of plant species
growing in periurban areas (Agrawal et al., 2003).
Urban air pollution has direct impact on periurban
agriculture due to dispersion of pollutants in all
directions along the wind. During transportation
primary pollutants often form secondary pollutants,
causing greater adverse effects on crop production in
periurban areas. Effects of air pollutants have been
* Corresponding author. Tel.: C91 542 2368156; fax: C91 542
2368174.
E-mail address: [email protected] (S.B. Agrawal).
0269-7491/$ - see front matter 2004 Elsevier Ltd. All rights reserved.
doi:10.1016/j.envpol.2004.09.017
Environmental Pollution 134 (2005) 385395
www.elsevier.com/locate/envpol
mailto:[email protected]://www.elsevier.com/locate/envpolhttp://www.elsevier.com/locate/envpolmailto:[email protected] -
8/14/2019 Amelioration of Indian urban air pollution phytotoxicity in Beta vulgaris L. by modifying NPK nutrients
2/11
described in terms of foliar injury (Jacobson and Hill,
1970), reduction in photosynthetic pigments (Agrawal
et al., 1982), inhibition of physiological processes (Saxe,
1991), alteration in metabolic functions (Malhotra and
Khan, 1984), enzyme activities (Nandi et al., 1986) and
nutrient uptake and suppression of growth and yield of
agricultural crop plants (Lee, 2000; Verma et al., 2000;Ribas and Penuelas, 2003; Singh et al., 2003).
Use of chemical protectants, such as growth regu-
lators, antioxidants and fertilizers is suggested to be
a short-term solution to reduce the risk of air pollution
damage. Researchers have suggested that application of
mineral nutrients promotes growth, and reduce pollut-
ant induced injury to crops (Ormrod et al., 1973).
Rajput and Agrawal (1994) have found that soybean
plants grown at recommended fertility levels were less
injured by SO2 in comparison to unfertilized crop.
In view of the above, the present investigation was
aimed to suggest an economical and ecofriendly solution
to ambient air pollution induced damage, by altering the
level of mineral nutrients in palak (Beta vulgaris var. All
Green) plants grown at different periurban and urban
sites of Allahabad city (Eastern Uttar Pradesh, India).
2. Materials and methods
The study was performed in the periurban and urban
environment of Allahabad city with a population of 0.85
million located in the eastern Gangetic plains of India
between 24 47#N latitude and 82 21#E longitude and
96 m above mean sea level. During the study period
mean minimum and mean maximum temperatures
ranged between 14.924.3 C and 30.834.6 C, respec-
tively (Table 1). The average relative humidity varied
between 59.8 and 68.4% and wind speed 3.56.8 km h1.
Total precipitation was 164.2 mm during September and
77 mm during October (Table 1). Prominent wind was
westerly. The plant species chosen for this study is
a cheap and popular vegetable and consumed mainly as
a source of iron in the diet. Periurban area of Allahabad
provides 85% of the palak crop consumed in the city.
An experiment was conducted from September to
November 2001 at seven selected sites (viz. AllahabadAgriculture Institute (AAI), Civil lines (CL), Mehdeori
(Mh), Jhunsi (Jh), Bahrana (Bh), Arail (Ar) and
Rajrooppur (RRP)) on the periphery and within the
city of Allahabad. The location of sites and a brief
description of their characteristics are given in Fig. 1
and Table 2. The soil was prepared at one place by
mixing garden soil and farmyard manure in 3:1 ratio
following the normal agronomical practices for unifor-
mity of edaphic conditions. Soil used in the experimenthad pH 7.62, organic carbon 1.64%, N 690 mg 100 g1
soil, P 16.4 mg 100 g1 soil and K 136.2 mg 100 g1.
Palak var. All Green seeds were sown in pots (30 cm
diameter) with four treatments of fertilizers, i.e. without
fertilizer (F0), recommended dose (RD) of N, P and K
(F1), one and half times of RD of N, P and K (F2) and
two times of RD of N, P and K (F3) on September 26,
2001. Recommended doses of NPK were 80, 40,
40 kg ha1, respectively. Nitrogen was given in form of
urea, phosphorus as single super phosphate and
potassium as murate of potash. Half dose of nitrogen
and full dose of phosphorus and potassium were given
as basal dressing and another half of nitrogen as top
dressing. After sowing, 32 pots were transferred to each
site. Pots were placed in unshaded open area receiving
uniform light. Micrometeorological variations in tem-
perature were 0.10.2 C, relative humidity 13%
between the sites. Light intensity was identical at all
sites. The pots were uniformly watered throughout the
experiment in order to maintain constant soil moisture.
For analysis, triplicate random samples of plants from
each treatment of each site were taken at 20 days after
sowing (DAS) and then at regular intervals of 15 days.
Final harvest was done on November 16, 2001 at 50
DAS. For total biomass determination, plants were ovendried at 80 C until the constant weight was obtained
and values were expressed as g plant1. The chlorophyll
content was expressed as mg g1 dry leaf and measured
by using the method of Machlachlan and Zalik (1963).
Carotenoid content was calculated by the method of
Duxbury and Yentsch (1956). Protein analysis in fresh
leaves was performed by using the method of Lowry
et al. (1951). Ascorbic acid in fresh leaves was measured
using the 2,6 dichlorophenol indophenol method of
Keller and Schwager (1977). Catalase and peroxidase
enzyme activities were determined using the methods of
Kar and Mishra (1976) and Britton and Mehley (1955),
respectively. Determination of reducing and total soluble
sugars was performed by reference to glucose standards
using the calorimetric copper method of Somogyi (1952)
and for starch extraction, the method ofMcCready et al.
(1950) was followed.
Air monitoring of gaseous pollutants (SO2, NO2 and
O3) was done with the help of gas samplers kept at
30 cm height from ground at each site by using wet
chemical methods. SO2, NO2 and O3 were measured by
methods of West and Gaeke (1956), Merryman et al.
(1973) and Byers and Saltzman (1958), respectively. No
continuous advanced gas analyzers were available and
Table 1
Meteorological data during the experimental period
Month and
year
Precipitation
(mm)
Temperature ( C) Relative
humidity
(%)
Wind
speed
(km h1)Max. Min.
September,
2001
164.2 34.6 24.3 68.4 6.8
October, 2001 77.0 33.7 20.7 64.6 4.2
November, 2001 0.0 30.8 14.9 59.8 3.5
386 A. Singh et al. / Environmental Pollution 134 (2005) 385395
-
8/14/2019 Amelioration of Indian urban air pollution phytotoxicity in Beta vulgaris L. by modifying NPK nutrients
3/11
gas samplers using wet chemical methods were the best
possible devices with the available resources. Monitor-
ing of pollutants was conducted for 6 h from 10 A.M. to
4 P.M. at weekly intervals at each site, this was the only
option to ensure the safety of the samplers and because
of frequent failure of electricity at various sites as
samplers have a battery back up of only 6 h.
Data were analyzed through three-way and two-way
ANOVA using SPSS software (SPSS Inc., version 10.0)
for assessing the significance of quantitative changes in
different parameters due to ambient air pollution.
3. Results
Results of air monitoring showed that RRP was the
most polluted sites among all experimental sites, where
SO2, NO2 and O3 were recorded in the range of 38.2
65.0, 30.842.5 and 17.030.8 mg m3, respectively. Min-
imum concentrations of SO2, NO2 and O3 ranged
between 10.618.3, 2.512.5 and 3.515.3 mg m3, re-
spectively at site Ar (Table 3). Since all the pollutants
showed minimum concentrations at Ar, this site was
treated as reference site for comparing the levels of
changes in various parameters recorded at other sites
with relatively elevated levels of pollutants.
Total biomass of palak plants was reduced with
increasing pollution load at all sampling intervals
(Fig. 2) Significant negative correlations were found
between total biomass and SO2 (rZ0.92, p! 0.01),
NO2 (rZ0.85, p! 0.05) and O3 (rZ0.91,
p! 0.01) (Table 4). F2 treatment showed a positive
response against air pollutants by increasing the total
biomass. Maximum total biomass (4.7 g plant1) was
Fig. 1. Map of Allahabad city showing location of experimental sites.
387A. Singh et al. / Environmental Pollution 134 (2005) 385395
-
8/14/2019 Amelioration of Indian urban air pollution phytotoxicity in Beta vulgaris L. by modifying NPK nutrients
4/11
recorded at site Ar in F2 treatment, which was 3.9 g
plant1 at F0 treatment. Total biomass was least at site
RRP (3.3 g plant1) under F0 treatment and it increasedto 4.3 g plant1 due to F2 treatment (Fig. 2). Three-way
ANOVA test showed that the variations in total
biomass were significant (p! 0.001) due to plant age,
site, nutrient treatment and their interactions (Table 5).
Total chlorophyll and carotenoid contents in palak
leaves were lower at sites experiencing higher pollution
load (Fig. 3). Maximum total chlorophyll (0.95 mg g1
dry leaf) and carotenoid contents (0.44 mg g1 dry leaf)
were observed at Ar (reference site) and minimum at
RRP, most polluted site (total chlorophyll 0.65 mg g1
dry leaf; carotenoid 0.3 mg g1 dry leaf) 50 DAS under
F2 treatment. Total chlorophyll and carotenoid contents
showed significant negative correlations with SO2(rZ1.0, p! 0.001 and rZ0.99, p! 0.001, respec-
tively), NO2 (rZ0.96, p! 0.001 and rZ0.98, p!
0.001, respectively) and O3 (rZ0.98, p! 0.001 and
rZ0.99, p! 0.001, respectively) (Table 4). ANOVA
test showed that total chlorophyll and carotenoid
contents varied significantly due to plant age, site,
fertilizer treatment and their interactions except for
plant age! site! fertilizer treatment interactions for
carotenoid (Table 5).
Protein and ascorbic acid contents showed significant
negative correlations with individual air pollutants
(Table 4). Protein content increased with the increase
of plant age, while ascorbic acid decreased. Maximum
protein and ascorbic acid contents were observed at 50
and 35 DAS, respectively under F2 treatment at Ar
(Fig. 4). Variations in for protein and ascorbic acid
Table 2
Brief description of experimental sites
Site code Experimental
site
Character of site Distance (km)
and direction
from city centre
AAI Allahabad
Agricultural
Institute
Near bank of river
Yamuna, and national
highway (NH-27); heavytraffic, frequent congestion,
heavy vehicles, medium
density population.
3 km south
Ar Arail Near bank of river
Yamuna, open, small
population
3 km south east
Bh Bahrana City centre, near national
highway (NH-2), heavy
and light motor vehicles,
frequent traffic jams, high
density population.
0 km
Jh Jhunsi Near national highway
(NH-2) periurban area
5 km east south
Mh Mehdeori Near bank of river
Ganga, light vehicles,
periurban area.
5.5 km north
CL Civil lines Commercial area, near
railway station, urban
area
2.5 km
north west
RRP Rajrooppur Near national highway
(NH-2), industries,
railway track, heavy
traffic, high density
population, urban area
6.5 km west
Table 3
Levels of SO2, NO2 and O3 at different sites during experiment
(mg m3)
Gaseous
pollutants
Experimental sites
CL Ar RRP Mh Jh Bh AAI
Sep., 2001
SO2 16.4 10.6 38.2 14.2 16.1 35.4 25.4
NO2 18.6 2.5 30.8 7.5 12.5 27.5 22.2
O3 10.2 3.5 17.0 6.5 8.4 16.4 12.5
Oct., 2001
SO2 40.0 15.3 55.7 23.5 30.2 51.2 44.6
NO2 24.4 8.0 36.6 14.6 20.5 31.9 26.5
O3 14.3 10.3 27.6 10.0 11.7 22.5 18.6
Nov., 2001
SO2 45.7 18.3 65.0 32.5 38.6 60.3 50.4
NO2 27.5 12.5 42.5 18.7 23.6 37.5 31.6
O3 20.4 15.3 30.8 15.9 16.9 26.4 24.0
Totalb
iomass(gplant-1)
Totalbiomass(gplant-1)
Totalbiomass(gplant-1)
0.0
0.1
0.2
0.3
0.4
0.5
0.6
1.0
1.5
2.0
2.5
3.0
3.5
4.0
Experimental sites
AAI CL Mh Jh Bh Ar RRP2.5
3.0
3.5
4.0
4.5
F0 F1 F2 F3 20 DAS
35 DAS
50 DAS
Fig. 2. Effect of air pollution on total biomass of palak plants grown at
different experimental sites with varying fertility levels.
388 A. Singh et al. / Environmental Pollution 134 (2005) 385395
-
8/14/2019 Amelioration of Indian urban air pollution phytotoxicity in Beta vulgaris L. by modifying NPK nutrients
5/11
contents were significant due to plant age, site, fertilizer
treatments (Table 5).
Catalase activity decreased with increasing levels of
air pollutants, while peroxidase activity increased
(Fig. 5). Catalase activity showed significant negative
correlations with SO2 (rZ0.97, p! 0.001), NO2 (rZ
0.95, p! 0.001) and O3 (rZ
0.95, p! 0.001), whileperoxidase activity showed highly significant positive
correlation with SO2 (rZ 0.99, p! 0.001), NO2 (rZ
0.95, p! 0.001) and O3 (rZ 0.98, p! 0.001) (Table 4).
Three-way ANOVA test showed significant variations in
enzyme activities due to plant age, site and fertilizer
treatment and their interactions except for plant
age! site, site! treatment and plant age! site!
treatment interactions for catalase activity (Table 5).
Starch and reducing sugar contents also decreased
with increasing levels of air pollutants while soluble
sugars increased (Fig. 6). Correlation matrix showed
a significant negative correlation between individual
pollutants and starch and reducing sugars and positive
correlation between soluble sugars and pollutants (Table
4). Starch, reducing sugars and soluble sugars varied
significantly due to plant age, site, fertilizer treatment
and their interactions except for plant age! site,
site! treatment and plant age! site! treatment for
starch and soluble sugars (Table 5).
4. Discussion
In many cities of developing countries, the levels of
air pollutants often exceed toxic limits and adverselyaffect human health, vegetation and built cultural
heritage. In urban areas of Allahabad city, high levels
of automobile emissions have elevated the levels of
pollutants to an extent that inhibited the plant growth
and reduced the yield of palak grown in urban and
periurban areas. Urban air quality of Varanasi, an
adjoining city of Allahabad has also been shown to
cause deleterious effects on woody transplants grown in
urban areas (Pandey and Agrawal, 1994) and yield
losses in crop plants grown in periurban areas (Agrawal
et al., 2003).
Air monitoring conducted in Varanasi has shown
that SO2 concentration varied from 14 to 43 mg m3,
NO2 from 16 to 34 mg m3 and O3 from 12 to 42 mg m
3
during the rainy season (JulyOctober) in urban areas
(Pandey et al., 1992). The levels of SO2 and NO2observed in the present study are similar to that of
Pandey et al. (1992), but O3 levels are low. From the
meteorological data it is clear that rains were frequent in
September and October, and hence all the pollutants
including O3 showed lower values during these months.
In November, however, O3 formation increased with
a longer sunshine period. The permissible annual safe
limits set by CPCB, India for 8 hourly SO2 and NO2Table4
Correlationmatrixofgaseouspollutants
andtotalbiomassanddifferentphysiologic
alandbiochemicalcharacteristicsofpalak
plants
Totalbiomass
Totalchlorophyll
Carotenoid
Protein
Ascorbicacid
Catalaseactivity
Peroxidaseactivity
Starch
Solublesugars
Reducingsugars
SO2
0.9
2**
0.9
9***
0.9
9***
0.9
6***
0.9
1**
0.9
7***
0.
99***
0.9
6***
0.9
5***
0.9
9***
NO2
0.8
5*
0.9
6***
0.9
8***
0.8
9**
0.9
5***
0.9
5***
0.
95***
0.9
4**
0.8
2*
0.9
7***
O3
0.9
1**
0.9
8***
0.9
9***
0.9
2**
0.9
5***
0.9
5***
0.
98***
0.9
6***
0.8
7**
0.9
9***
Totalbiomass
1.0
0
0.8
8**
0.8
9**
0.8
5*
0.8
5*
0.8
1*
0.
93**
0.8
5**
0.8
8**
0.9
0**
Totalchlorophyll
1.0
0
0.9
9***
0.9
8***
0.9
4**
0.9
8***
0.
99***
0.9
8***
0.9
3**
0.9
9***
Carotenoid
1.0
0
0.9
4**
0.9
4**
0.9
8***
0.
98***
0.9
6***
0.9
0**
0.9
9***
Protein
1.0
0
0.9
1**
0.9
4**
0.
96***
0.9
7***
0.9
5***
0.9
6***
Ascorbicacid
1.0
0
0.8
8**
0.
95***
0.9
7***
0.8
0*
0.9
4*
Catalaseactivity
1.0
0
0.
94***
0.9
4*
0.9
0**
0.9
8***
Peroxidaseactivity
1.
00
0.9
8***
0.9
4**
0.9
9***
Starch
1.0
0
0.9
0**
0.9
7***
Solublesugars
1.0
0
0.9
1**
Reducingsugars
1.0
0
*p
!
0.0
5,
**p
!
0.0
1,
***p
!
0.0
01and
NSZ
notsignificant.
389A. Singh et al. / Environmental Pollution 134 (2005) 385395
-
8/14/2019 Amelioration of Indian urban air pollution phytotoxicity in Beta vulgaris L. by modifying NPK nutrients
6/11
concentrations in urban areas are 60mg m3. SO2concentration crossed this limit at two sites (RRP and
Bh) during September. NO2 concentration remained
always below the permissible limit. There is no
permissible safe limit set for O3 in India. Since the
monitoring of pollutants was conducted on 6 hourly
sample collections, the measurement of peak concen-
trations in between cannot be provided. In Varanasi, 2 h
Table 5
Variance ratio for total biomass, photosynthetic pigments, protein, ascorbic acid, enzyme activities and carbohydrate content of palak plants grown
with different fertility levels at various experimental sites
Parameter Plant age (A) Site (B) Treatment (C) A!B A!C B!C A!B!C
Total biomass *** *** *** *** *** *** ***
Total chlorophyll *** *** *** *** *** *** ***
Carotenoid *** *** *** *** *** *** NS
Protein *** *** *** NS *** NS NSAscorbic acid *** *** *** NS *** NS NS
Catalase activity *** *** *** NS *** NS NS
Peroxidase activity *** *** *** * *** ** **
Starch *** *** *** NS *** NS NS
Soluble sugars *** *** *** NS *** NS NS
Reducing sugars *** *** *** ** *** *** ***
*p! 0.05, **p! 0.01, ***p! 0.001 and NSZ not significant.
0.1
0.2
0.3
0.4
0.5
0.6
0.7
Totalchlorophyll(mgg-1dryleaf)
0.2
0.3
0.4
0.5
0.6
0.7
0.8
AAI CL Mh Jh Bh Ar RRP
0.2
0.4
0.6
0.8
1.0
0.0
0.5
0.1
0.2
0.3
0.4
Carotenoid(mgg-1dryleaf)
0.0
0.1
0.2
0.3
0.4
Experimental sites Experimental sites
AAI CL Mh Jh Bh Ar RRP
0.0
0.1
0.2
0.3
0.4
0.5
F0 F1
F2F3
F0F1
F2F3
50 DAS 50 DAS
35 DAS 35 DAS
20 DAS20 DAS
Fig. 3. Effect of air pollution on total chlorophyll and carotenoid contents in leaves of palak plants grown at different experimental sites with varying
fertility levels.
390 A. Singh et al. / Environmental Pollution 134 (2005) 385395
-
8/14/2019 Amelioration of Indian urban air pollution phytotoxicity in Beta vulgaris L. by modifying NPK nutrients
7/11
peak concentrations of SO2 varied from 25 to 95 mg m3,
NO2 from 27 to 61 mg m3 and O3 from 21 to 102 mg m
3
in periurban and urban areas (Pandey et al., 1992). Peak
concentration affects vegetation more adversely than
prolonged exposure to low concentrations (Lefohn and
Jones, 1986). The lower O3 concentration recorded
during the present study may also be ascribed to the
presence of monitoring sites near roads, where O3 is
quickly scavenged.
The adverse effects of urban air pollutants are clearly
evident on physiological and biochemical processes of
palak plants during the present investigation. Photo-
synthetic pigments are fairly sensitive to air pollutants
and their sensitivity may determine the responses of
plants to pollutants. Significant negative correlations
were obtained between air pollutants and total chloro-
phyll and carotenoid contents. Khan and Khan (1994)
reported that combined treatments of O3 and SO2 at all
concentrations had a significant negative effect on the
leaf pigments. Exposure to SO2 causes more reduction in
chlorophyll than carotenoids in wheat plants (Verma
and Agrawal, 2001). El-Khatib (2003) also reported
reductions in chlorophyll and carotenoid contents
35 DAS50 DAS
Experimental sites
AAICL Mh Jh Bh Ar RRP
0.45
0.60
0.75
0.90
Experimental sites
AAICL Mh Jh Bh Ar RRP
Ascorbicacid(mgg-1freshleaf)
0.8
1.2
1.6
50 DAS35 DAS
10
11
12
13
14
15
Protein(mgg-1freshleaf)
Ascorbicacid(mgg-1freshleaf)
Protein(mgg-1freshleaf)
6
7
8
9
10
11
12
13
14
F0 F1F2 F3
Fig. 4. Effect of air pollution on protein and ascorbic acid contents in
leaves of palak plants with varying fertility levels at different
experimental sites.
20
30
40
50
60
70
80
90
Experimental sites
AAI CL Mh Jh Bh Ar RRP
Perox
idaseactiv
ity
(mM
purpuroga
llinformedm
in-1
g-1
fresh
lea
f)
Ca
talaseact
ivity
(mM
H2
O2
decompose
dm
in-1g-1
fresh
lea
f)
0
1
2
3
4
5
F0 F1
F2 F3
Fig. 5. Effect of air pollution on catalase and peroxidase activity in
leaves of palak plants at 50 DAS with varying fertility levels at
different experimental sites.
300
325
350
375
400
175
200
225
250
275
300
Experimental sites
AAI CL Mh Jh Bh Ar RRP
Reducingsugars(mgg-1dryleaf)
Solublesugars(mgg-1dryleaf)
Starc
h(mgg-1dryleaf)
150
200
250
F0 F1 F2 F3
Fig. 6. Effect of air pollution on starch, soluble and reducing sugar
contents in leaves of palak plant at 50 DAS sites with varying fertility
levels at different experimental.
391A. Singh et al. / Environmental Pollution 134 (2005) 385395
-
8/14/2019 Amelioration of Indian urban air pollution phytotoxicity in Beta vulgaris L. by modifying NPK nutrients
8/11
caused by elevated levels of O3 in five common Egyptian
plant species. Nutrient amendment in various combina-
tions significantly lowered the magnitude of reduction in
chlorophyll as compared to unamended plants (F0treatment). Verma et al. (2000) also reported that
nutrient amendment lowered the magnitude of reduc-
tion in chlorophyll content as compared to unamendedones, confirming the results of the present investigation.
Nitrogen supply is reported to increase the leaf
photosynthesis via the amount of N-containing compo-
nents such as ribulose-1,5 bisphosphate carboxylase/
oxygenase activity (Sivasankar et al., 1993) and also by
chlorophyll formation (Agrawal and Verma, 1997).
However, N and P deficiency reduces the chlorophyll
concentration (Rousseau and Reid, 1990).
Air pollutants are known to induce the degradation of
biologically important molecules such as proteins with
the consequent release of malondialdehyde (Mudd,
1982). Protein content showed significant negative cor-
relations with air pollutants and significant increase in
protein content was observed due to application of
mineral nutrients at all sites. The protein content
depends upon N uptake and plants receiving a higher
dose assimilate more N as compared to the unamended
plants. Plants grown with higher N-supply invest
a greater proportion of carbon in protein (Makino et al.,
1984). Verma and Agrawal (1996) also noticed that N, P
and K amendment in soybean plants significantly
reduced the levels of decrease in protein content of SO2exposed plants.
Ascorbate is a ubiquitous soluble antioxidant in
photosynthetic organisms and the most importantreducing substrate for H2O2 detoxification. It has been
suggested that pollutants produce oxyradicals in plants
(Shimazaki et al., 1980; Sakaki et al., 1983). These
radicals cause widespread damage to membranes and
associated molecules including the chlorophyll pigments
(Sakaki et al., 1983). Several authors have reported that
ascorbic acid can serve as a free radical scavenger
against O3 (van Hove et al., 2001; El-Khatib, 2003). The
reduction in ascorbic acid concentration may be
ascribed to its consumption during removal of cytotoxic
free radicals generated in chain reactions after the
penetration of oxidative pollutants into leaf tissues.
Agrawal and Verma (1997) also observed higher
ascorbic acid content in SO2 exposed plants amended
with fertilizers.
Peroxidase activity showed an increasing trend with
increasing pollution levels at various sites, while catalase
activity decreased. Singh (1998) also found that wheat
plants exposed to O3 showed increase in peroxidase
activity without any specific symptoms of O3 on foliage.
Tingey et al. (1975) stated that stimulation of peroxidase
activity in pollutant-exposed plants might be due to
increased oxidative processes under pollutant stress.
Present observations are in conformity with the earlier
findings of Ranieri et al. (1997), who showed that
catalase activity decreased with increase in SO2 levels
while peroxidase activity increased.
Starch content showed significant negative correla-
tion with individual pollutants. Rennenberg et al. (1996)
suggested that O3 probably interacts with carbon
allocation by inhibiting sucrose export. This causes anaccumulation of starch in leaves, which results in
reduction of photosynthesis and consequently reduces
the level of starch in plants. Nutrient amendment in
different combinations has significantly elevated the
levels of starch in plants. Agrawal and Verma (1997)
also reported reduction in foliar starch content of two
cultivars of wheat treated with SO2 compared with
untreated plants and also found significant increase after
nutrients application.
An increase in total soluble sugars was recorded
with increasing pollution levels while reducing sugars
reduced. The adverse effects of air pollutants are evident
in the form of changes in pool volume of free carbo-
hydrates in palak grown at different sites with various
fertility levels. Katase et al. (1983) reported that SO2-
induced inhibition of photosynthesis in rice reduced the
level of starch in the plants. An increase in concentration
of sugar was associated with reduced starch content,
suggesting increased hydrolysis of polysaccharides into
monosaccharides due to gaseous pollution (Koziol and
Jorden, 1978). Nutrient amendment has significantly
reduced the level of decrease in starch and reducing sugar
contents at various sites, which might be due to increased
photosynthetic rate led by nutrient amendment. Meyer
et al. (2000) reported that O3 caused inhibition ofphotosynthesis, and consequently decline in assimilate
production. Agrawal et al. (2003) have also reported
significant reductions in photosynthetic rate of a number
plant species growing in a periurban area of Varanasi
experiencing higher level of pollutants.
Total biomass accumulation reduced in palak with
increasing pollution load at various sites. This suggests
that air pollutants directly interfere with various
fundamental processes of plants, resulting in lower
biomass accumulation. Ashmore et al. (1987) have also
reported a decline in biomass accumulation in different
plant parts along a gradient of air pollution around
London. Agrawal et al. (2003) have also reported a
negative correlation between ambient air pollutant levels
and biomass accumulation in plants grown in the out-
skirts of Varanasi city experiencing similar climatic
conditions. Verma et al. (2000) reported that 390 mg m3
SO2 treatment for 4 h daily for 5 days week1 for 8
weeks resulted in a significant reduction in biomass
accumulation and productivity in wheat plants were due
to the integrated result of effects on a range of bio-
chemical, physiological and metabolic activities in
plants. The joint action of O3 and SO2 caused significant
suppression in dry matter of tomato shoot and root at
392 A. Singh et al. / Environmental Pollution 134 (2005) 385395
-
8/14/2019 Amelioration of Indian urban air pollution phytotoxicity in Beta vulgaris L. by modifying NPK nutrients
9/11
all concentrations (Khan and Khan, 1994). McKee et al.
(1997) also reported that elevated O3 caused a 15%
decline in total biomass accumulation in wheat plants.
Fertilizer amendment has a significant effect on plant
response to air pollutants. Agrawal and Verma (1997)
reported that plant height and total biomass reduced
significantly in SO2 treated plants, except those grownusing recommended and twice recommended N, P and
K applications. In the present investigation, F2 treat-
ment showed the most positive impact on biomass
accumulation and photosynthetic pigments by decreas-
ing the negative impact of air pollutants. The percent
reduction in total biomass at 50 DAS was 15.5 and
9.5%, respectively at RRP site in nutrient unamended
and amended plants as compared to the same growing at
Ar site experiencing lowest levels of air pollutants. The
double recommended dose of nutrients showed maxi-
mum percent reduction in total biomass (29% at RRP
site compared to Ar site) suggesting that this dose is
supra optimal and caused negative influence on the
plants. Application of nutrients higher than the demand
has been shown to reduce the positive effects of
fertilizers (Agrawal and Verma, 1997; Verma et al.,
2000). Recently, Singh et al. (2003) also revealed that air
pollutants suppressed the growth and yield of wheat
plants grown at various urban and periurban sites of
Allahabad but fertilizer amendment higher than the
recommended dose resulted in a positive response by
increasing the total biomass, weight of 1000 seeds and
yield.
The supply of macro nutrients N, P and K increased
the total biomass in palak by increasing the levels ofphotosynthetic pigments, antioxidative property and
metabolites in foliar tissue, which have further reduced
the magnitude of reduction in biomass due to air
pollutants compared to unfertilized plants. Coleman
et al. (1989) have suggested that plants growing in
nutrient poor conditions may be more sensitive to air
pollution with respect to changes in carbon gain. N
limitation has been shown to decrease chlorophyll and
protein contents, RuBP carboxylase activity and in-
crease the mesophyll resistance, which all limit CO2fixation (Osman and Milthorpe, 1971). High P avail-
ability is found to increase the rate of photosynthesis
(Rousseau and Reid, 1990). K fertilization is also
beneficial due to its role in stomatal opening, photosyn-
thesis, protein synthesis and osmotic and pH regulation
(Wyn Jones and Pollard, 1983).
5. Conclusions
The data obtained in the present investigation suggest
that both air pollutants and nutrient deficiency have
caused adverse impact on various physiological and
biochemical processes and total biomass accumulation
of palak plants grown at sites experiencing elevated
pollutant concentrations. Increasing pollution load also
deteriorated the nutritive quality of palak plants, as
protein and carbohydrate contents were decreased. One
and half times of recommended dose of NPK was most
efficient in reducing the adverse effects of air pollutants
on palak plants. The present investigation also suggeststhat urban air quality of Allahabad city is unfavourable
for vegetable production in urban and periurban areas.
Though the concentrations of individual pollutants were
not very high except SO2, the levels of reductions were
fairly significant. This clearly shows that pollutants in
combination may have acted synergistically in causing
greater adverse impact. Low concentrations of pollu-
tants have been shown to increase the stomatal
conductance thus facilitating the pollutant uptake and
consequently greater negative response. Palak plants
seem to be fairly sensitive to air pollutants under
ambient conditions. More large-scale studies are,
however, required to ascertain the potential for use of
this plant as a biomonitor of air pollution.
Acknowledgements
Authors wish to express sincere thanks to Prof. R.B.
Lal, Vice Chancellor, Allahabad Agricultural Institute -
DU and Prof. P.W. Ramteke, Director (Research) for
providing laboratory facilities and encouragements and
to C.S.I.R. (New Delhi) for providing financial support.
Authors are also grateful to Professor Madhoolika
Agrawal (B.H.U.) and to anonymous reviewers forcomments and fruitful suggestions.
References
Agrawal, M., Nandi, P.K., Rao, D.N., 1982. Effect of ozone or SO 2pollutants separately and in mixture on chlorophyll and carotenoid
pigments of Oryza sativa. Water, Air and Soil Pollution 18,
449454.
Agrawal, M., Verma, M., 1997. Amelioration of sulphur dioxide
phytotoxicity in wheat cultivars by modifying NPK nutrients.
Journal of Environmental Management 49, 231244.
Agrawal, M., 1998. Effect of air pollution on urban agriculture in andaround Varanasi city. Final technical report of ODA sponsored
research project, Department of Botany, Banaras Hindu Univer-
sity, Varanasi, India.
Agrawal, M., Singh, B., Rajput, M., Marshall, F., Bell, J.N.B., 2003.
Effect of air pollution on peri-urban agriculture: a case study.
Environmental Pollution 126, 323329.
Ashmore, M.R., Brown, V., Kristiansen, L., Shah, D., 1987. Effects of
ambient air pollution, water stress and aphid pests on Vicia faba.
In: Bonte, J., Mathy, P. (Eds.), The European Communities
Research Project on Open-top Chambers. Results on Agricultural
Crops. Commission of the European Communities, Brussels.
Britton, C., Mehley, A.C., 1955. Assay of catalase and peroxidase. In:
Colowick, S.P., Kaplan, N.O. (Eds.), Methods in Enzymology, vol.
II. Academic press, New York, pp. 764775.
393A. Singh et al. / Environmental Pollution 134 (2005) 385395
-
8/14/2019 Amelioration of Indian urban air pollution phytotoxicity in Beta vulgaris L. by modifying NPK nutrients
10/11
Byers, D.H., Saltzman, B.E., 1958. Determination of ozone in air by
neutral and alkaline iodide procedures. Journal of American
Industrial Hygiene Association 19, 251257.
Coleman, J.S., Mooney, H.A., Gorham, J.N., 1989. Effects of
multiple stresses on radish growth and resource allocation I.
Responses of wild radish plants to a combination of SO2exposure and decreasing nitrate availability. Oecologia 81,
124131.
Duxbury, A.C., Yentsch, C.S., 1956. Plankton pigment monographs.
Journal of Marine Research 15, 91101.
El-Khatib, A.A., 2003. The response of some common Egyptian plants
to ozone and their use as biomonitors. Environmental Pollution
124, 419428.
van Hove, L.W.A., Bossen, M.E., Son Gabino, B.G., Sgreva, C., 2001.
The ability of apoplastic ascorbate to protect poplar leaves against
ambient ozone concentrations: a quantitative approach. Environ-
mental Pollution 114, 371382.
Jacobson, J.S., Hill, A.C. (Eds.), 1970. Recognition of Air Pollution
Injury to Vegetation: A Pictorial Atlas. Air Pollution Control
Association, Pittsburgh, PA, 102 pp.
Kar, M., Mishra, D.C., 1976. Catalase, peroxidase and polyphenolox-
idase activities during rice leaf senescence. Plant Physiology 57,
315317.
Katase, M., Ushijima, T., Tazaki, T., 1983. The relationship between
absorption of sulphur dioxide (SO2) and inhibition of
photosynthesis in several plants. Botanical Magazine Tokyo 96,
113.
Keller, T., Schwager, H., 1977. Air pollution and ascorbic acid.
European Journal of Forest Pathology 7, 338350.
Khan, M.R., Khan, M.W., 1994. Single and interactive effect of O 3and SO2 on tomato. Environmental and Experimental Botany 34
(4), 461469.
Koziol, M.J., Jorden, C.F., 1978. Changes in carbohydrate levels in red
kidney bean (Phaseolus vulgaris L.) exposed to sulphur dioxide.
Journal of Experimental Botany 29, 10371043.
Lee, E.H., 2000. Early detection, mechanisms of tolerance and
amelioration of ozone stress in crop plants. In: Agrawal, S.B.,
Agrawal, M. (Eds.), Environmental Pollution and Plant Responses.Lewis Publishers, Boca Raton, USA, pp. 203222.
Lefohn, A.S., Jones, C.K., 1986. The characterization of ozone and
sulfur dioxide air quality data for assessing possible vegetation
effects. Journal of Air Pollution Control Association 36, 1123
1129.
Lowry, O.H., Rosebrough, N.J., Farr, A.L., Randall, R.J., 1951.
Protein measurement with the Folin phenol reagent. Journal of
Biological Chemistry 193, 265275.
Machlachlan, S., Zalik, S., 1963. Plastid structure, chlorophyll
concentration and free amino acid composition of chlorophyll
mutant barley. Canadian Journal of Botany 4, 10531063.
Makino, A., Moe, T., Ohira, K., 1984. Relationship between nitrogen
and ribulose 1,5 bisphosphate carboxylase in rice leaves from
emergence through senescence. Plant and Cell Physiology 25,
429437.Malhotra, S.S., Khan, A.A., 1984. Biochemical and physiological
impact of major pollutants. In: Treshow, M. (Ed.), Air Pollution
and Plant Life. John Wiley, New York, pp. 113157.
McCready, R.M., Goggoty, J., Strik-Timmer, W., Kuiper, P.J.C.,
1950. Determination of starch and amylose in vegetables.
Analytical Chemistry 22, 11561158.
McKee, I.F., Bullimore, J.F., Long, S.P., 1997. Will elevated CO2concentrations protect the yield of wheat from O3 damage? Plant,
Cell and Environment 20, 7784.
Merryman, E.L., Spicer, C.W., Lery, A., 1973. Evaluation of arsenite
modified Jacobs Hochheiser procedure. Environmental Science and
Technology 7, 10561059.
Meyer, U., Kollner, B., Willenbrink, J., Krause, G.H.M., 2000. Effects
of different ozone exposure regimes on photosynthesis, assimilates
and thousand grain weight in spring wheat. Agriculture, Ecosys-
tems and Environment 78, 4955.
Mudd, J.B., 1982. Effects of oxidants on metabolic functions. In:
Unsworth, M.H., Ormrod, D.P. (Eds.), Effects of Gaseous Air
Pollutants in Agriculture and Horticulture. Butterworths, London,
pp. 189203.
Nandi, P.K., Agrawal, M., Rao, D.N., 1986. Effects of fumigation rice
plants with sulphur dioxide on photosynthetic pigments and non-
structural carbohydrates. Agriculture, Ecosystems and Environ-
ment 18, 5362.
Ormrod, D.P., Adedipe, N.O., Hofstra, G., 1973. Ozone effects on
growth of radish plants as influenced by nitrogen and phosphorus
nutrition and by temperature. Plant and Soil 39, 437439.
Osman, A.M., Milthorpe, F.L., 1971. Photosynthesis of wheat leaves
in relation to age, illuminance and nutrient supply. II. Results.
Photosynthetica 5, 6170.
Pandey, J., Agrawal, M., 1994. Evaluation of air pollution phytotox-
icity in a seasonally dry tropical urban environment using three
woody perennials. New Phytologist 126, 5361.
Pandey, J., Agrawal, M., Khanam, N., Narayan, D., Rao, D.N., 1992.
Air pollutant concentrations in Varanasi, India. Atmospheric
Environment 26 B, 9198.
Rajput, M., Agrawal,M., 1994. Responses of soybean plants to sulphur
dioxide at varying soil fertility regimes. Biotronics 23, 8192.
Ranieri, A., Castagna, A., Lorenzini, G., Soldatini, G.F., 1997.
Changes in thylakoid protein patterns and antioxidant levels in two
wheat cultivars with different sensitivity to sulphur dioxide.
Environmental and Experimental Botany 37, 125135.
Rennenberg, H., Herschbach, C., Polle, A., 1996. Consequences of air
pollution on shootroot interactions. Journal of Plant Physiology
148 (34), 296301.
Ribas, A., Penuelas, J., 2003. Biomonitoring of tropospheric ozone
phytotoxicity in rural Catalonia. Atmospheric Environment 37,
6371.
Rousseau, J.V.D., Reid, C.P.P., 1990. Effects of phosphorus and
ectomycorrhizas on the carbon balance of loblolly pine seedlings.
Forest Science 36, 101112.
Sakaki, T., Kondo, N., Sugahara, K., 1983. Breakdown of photosyn-thetic pigments and lipids in spinach leaves with ozone fumigation:
role of active ozone. Physiologia Plantarum 59, 2334.
Saxe, H., 1991. Photosynthesis and stomatal response to polluted
air and the use of physiological and biochemical responses for
easy detection and dignostic tools. In: Callow, J.A. (Ed.),
Advances in Botanical Research, vol. 18. Academic Press,
Toronto, pp. 1128.
Shimazaki, K., Sakaki, T., Kondo, N., Sugahara, K., 1980. Active
oxygen participation in chlorophyll destruction and lipid perox-
idation in SO2 exposed leaves of spinach. Plant and Cell Physiology
21, 11931204.
Singh, A., Agrawal, S.B., Rathore, D., 2003. Growth responses of
wheat (Triticum aestivum L. var. HD 2329) exposed to ambient air
pollution under varying fertility regimes. The Scientific World
Journal 3, 799810.Singh, E., 1998. Effect of ozone pollution on selected crop plants; PhD
thesis, Banaras Hindu University, Varanasi, India.
Somogyi, H., 1952. Notes on sugar determination. Journal of
Biological Chemistry 195, 1923.
Sivasankar, A., Bansal, K.C., Abrol, Y.P., 1993. Nitrogen in relation
to leaf area development and photosynthesis. Proceeding of the
Indian National Sciences Academy B59, 235244.
Tingey, D.T., Fites, R.C., Wickliff, C., 1975. Activity changes in
selected enzymes from soybean leaves following ozone exposure.
Physiologia Plantarum 33, 316320.
Verma, M., Agrawal, M., Deepak, S.S., 2000. Interactive effects of
sulphur dioxide and mineral nutrient supply on photosynthetic
characteristics and yield in four wheat cultivars. Photosynthetica 38
(1), 9196.
394 A. Singh et al. / Environmental Pollution 134 (2005) 385395
-
8/14/2019 Amelioration of Indian urban air pollution phytotoxicity in Beta vulgaris L. by modifying NPK nutrients
11/11
Verma, M., Agrawal, M., 1996. Alleviation of injurious
effects of sulphur dioxide on soybean by modifying NPK
nutrients. Agriculture, Ecosystems and Environment 57,
4955.
Verma, M., Agrawal, M., 2001. Response of wheat plants to sulfur
dioxide and herbicide interaction at different fertility regimes.
Journal of Indian Botanical Society 80, 6772.
West, P.W., Gaeke, G.C., 1956. Fixation of SO2 as sulfitomurcurate
(II) and subsequent colorimetric estimation. Analytical Chemistry
28, 18161819.
Wyn Jones, R.G., Pollard, A., 1983. Proteins, enzymes and inorganic
ions. In: Lauchli, A., Bieleski, R.L. (Eds.), Inorganic Plant
Nutrition, Encyclopedia of Plant Physiology, New Series. Springer
Verlag, Berlin, 15B.
395A. Singh et al. / Environmental Pollution 134 (2005) 385395