ArticlePDF Available

Effect of sulphur nutrition on pungency and storage life of short day onion (Allium cepa)

Authors:

Abstract and Figures

A field experiment was carried out to evaluate the effect of sulphur nutrition at 0, 7.5, 10, 20, 30, 40 and 50 kg S/ha on pyruvic acid and storage life of onion bulbs in Vertic Haplustepts. Besides that, the effect of sulphur nutrition on soil available sulphur level, marketable bulb yield and sulphur uptake were also assessed. The results of this study revealed that sulphur application increased marketable bulb yield, sulphur uptake and pungency level over no sulphur treatment. Moreover the increase in bulb yield and sulphur uptake was less with increasing the sulphur level beyond 20 kg/ ha. The pyruvic acid content had significant and positive correlation with sulphur application (r2=0.735**). Sulphur application did not influence the storage life of onion bulbs significantly and showed no significant correlation with total storage losses of onion bulbs (r2= -0.0828). Soil sulphur level after harvest was increased over the initial values with application of sulphur @ 30, 40 and 50 kg S/ha while application of 7.5 kg S/ha and control without sulphur reduced soil available sulphur content. From this study, we conclude that sulfur nutrition is essential for increasing the onion yield and pungency level in soils having sufficient sulphur. However, excess sulphur application did not influence the yield and pungency level significantly. The storage life of onion bulbs were not influenced significantly by sulphur nutrition and application of either low or higher sulphur is detrimental to soil health.
Content may be subject to copyright.
Indian Journal of Agricultural Sciences 83 (10): 1086–9, October 2013/Article
Effect of sulphur nutrition on pungency and storage life of short day
onion (Allium cepa)
A THANGASAMY1, V SANKAR2, and K E LAWANDE3
Directorate of Onion and Garlic Research, Rajgurunagar, Pune, Maharashtra 410 505
Received: 30 May 2011; Revised accepted: 2 September 2013
ABSTRACT
A field experiment was carried out to evaluate the effect of sulphur nutrition at 0, 7.5, 10, 20, 30, 40 and 50 kg S/ha
on pyruvic acid and storage life of onion bulbs in Vertic Haplustepts. Besides that, the effect of sulphur nutrition on soil
available sulphur level, marketable bulb yield and sulphur uptake were also assessed. The results of this study revealed
that sulphur application increased marketable bulb yield, sulphur uptake and pungency level over no sulphur treatment.
Moreover the increase in bulb yield and sulphur uptake was less with increasing the sulphur level beyond 20 kg/ ha. The
pyruvic acid content had significant and positive correlation with sulphur application (r2=0.735**). Sulphur application
did not influence the storage life of onion bulbs significantly and showed no significant correlation with total storage
losses of onion bulbs (r2= -0.0828). Soil sulphur level after harvest was increased over the initial values with application
of sulphur @ 30, 40 and 50 kg S/ha while application of 7.5 kg S/ha and control without sulphur reduced soil available
sulphur content. From this study, we conclude that sulfur nutrition is essential for increasing the onion yield and pungency
level in soils having sufficient sulphur. However, excess sulphur application did not influence the yield and pungency
level significantly. The storage life of onion bulbs were not influenced significantly by sulphur nutrition and application of
either low or higher sulphur is detrimental to soil health.
Key words: Bulb yield, Soil health, Soil sulphur level, Sulphur uptake
1Scientist (e mail: astsamy@yahoo.co.in), 2Senior Scientist
(e mail: skar_hort@yahoo.com); 3Vice Chancellor (e mail:
vcbskkv@yahoo.co.in), Dr. BSKKV, Dapoli
any significant increase in pungency with sulphur application
to soil having high sulphur content.
Sulphur nutrition has also been shown to affect the bulb
firmness and dry weight of onion bulbs. Lancaster et al.
(2001) showed low sulphur supply reduced the sulphur in
cell walls and also decreased the bulb hardness and the
storage life of onion bulbs. Qureshi and Lawande (2006)
also reported that the storage losses were decreased with
application of sulphur. However, the information about the
influence of sulphur nutrition on pungency level and storage
life of onion is unclear. Hence the present study was carried
out to evaluate the effect of different levels of sulphur nutrition
on pungency level and storage life of onion bulbs.
MATERIALS AND METHODS
A field experiment was conducted at Directorate of
onion and Garlic Research, Pune, Maharashtra during rabi
season during 2008-09 and 2009-10 with onion cv. N-2-4-1.
The soil was clay loam in texture and had pH (1:2.5) 7.92,
electrical conductivity 0.24 dS/m, organic carbon 6.45 g/kg
soil, available N 200 kg/ha, P 23.0 kg/ha, K 578 kg/ha and S
14 ppm. The irrigation water contained 17 ppm of sulphur.
Six levels of sulphur (0, 7.5, 10, 20, 30, 40 and 50 kg/ha)
Onion (Allium cepa L.) is an important spicy vegetable
crop grown since ancient times by the farmers. The bulbs
and leaves of onion are used for flavoring the dishes all over
the world. Pungent flavour of onion is derived from number
of volatile sulphur compounds. These compounds are
produced when the onion cell is mechanically disrupted,
bringing the enzyme allinase into contact with flavor
precursors such as S- alk(en)yl-L-cysteine sulfoxides
(ACSOs). Besides the volatile sulphur compounds, the
enzymatic break down of ACSOs also produces ammonia,
pyruvic acids and lachrymator factor. The amount of pyruvic
acid generated has been shown to be correlated with onion
pungency. This enzymatically produced pyruvic acid is
commonly accepted measure of pungency. Several studies
have been conducted to determine the influence of sulphur
level on onion pungency ( McCallum et al. 2005) who
indicated increased pungency level with higher sulphur
nutrition in the soil while Lee et al. (2009) did not observe
86
1087October 2013]
were applied through elemental sulphur (90% water soluble
powder form). The trial comprised 7 treatments: T1- NPK
alone; T2- T1 +7.5 kg S; T3-T1+10 kg S; T4-T1+20 kg S; T5-
T1+30 kg S, T6-T1+ 40 kg S and T7-T1+ 50 kg S. The
experiment was laid out in randomized block design with 3
replications. Nitrogen, phosphorus and potassium were
applied as per recommended dose of fertilizer, ie 150:50:80
kg NPK/ha, respectively. Half of nitrogen, whole of P, K and
S were applied at the time of transplanting during the
December. Remaining nitrogen was applied in two equal
splits, at 30 and 45 days after transplanting. Standard package
of practices were followed to grow onion crop. The crop was
harvested after attaining maturity during last week of April.
Bulbs were covered by its top and left in the field for curing
for 3-4 days. After neck cutting, the bulb yield was recorded.
Representative bulb samples were collected for the
biochemical and nutritional analysis. Chopped bulb samples
were dried in oven at 60º C till the constant weight was
attained. The soil samples from 0-15 cm were collected
randomly using auger after harvest for analyzing the available
sulphur content in soil. The available sulphur in soil was
extracted using 0.15 % CaCl2. While the plant samples were
digested using nitric acid and perchloric acid mixture. The
plant digests and soil extractant were used for estimating the
sulphur content using turbidimetric method (Chesnin and
Yien 1950). The total soluble solid (TSS) of onion bulbs
were estimated using hand refractometer and the percent
TSS was noted down. Pyruvic acid content was estimated
using dinitro phenyl hydrazine (DNPH) reagent method.
Two opposite quarters of onion bulbs were selected and
made into pieces after removing the neck, basal plate and
skins. The onion tissues were crushed in a home mixer
grinder without adding water. Bulb tissues were blended
with equal volumes of water for 10 minutes. The homogenate
was filtered through Whatman No. 4 filter paper and the
filtrate was used for pyruvic acid analysis (Schwimmer and
Weston 1961).
The onion bulbs @ 20 kg from each treatment in three
replications were stored in perforated plastic crates under
top and bottom ventilated storage structure under ambient
conditions. Storage losses were recorded every month while
sorting samples up to 150 days from the date of harvest.
Cumulative storage losses were calculated (sum of
physiological loss of weight, sprouting loss and rotting loss)
and expressed in per cent. Analytical values obtained were
subjected to statistical analysis using Statistical Analytical
System (SAS) software.
RESULTS AND DISCUSSION
Available sulphur content in soil
Soil sulphur content ranged from 12 - 17 ppm among the
87
EFFECT OF SULPHUR NUTRITION ON PUNGENCY AND STORAGE LIFE OF SHORT DAY ONION
Table 1 Effect of sulphur application on marketable bulb yield of onion crop
Sulphur levels Marketable bulb yield Pyruvic acid content TSS
(kg S/ha) (tones/ha) (µmols/ gfresh weight) (%)
2008-09 2009-10 2008-09 2009-10 2008-09 2009-10
0 50.91 a 41.30 c 3.74 e 3.20 b 11.50 a 12.97 a
7.5 51.83 a 44.77 b 3.68 e 3.35 b 12.97 a 13.14 a
10 55.50 a 44.37 b 4.12 d 3.52 b 11.60 a 13.63 a
20 55.83 a 45.70 ab 4.32 c 4.40 a 11.26 a 13.30 a
30 54.08 a 47.57 a 4.34 bc 4.47 a 12.07 a 13.23 a
40 53.75 a 44.93 b 4.51 ab 4.80 a 12.27 a 13.42 a
50 56.25 a 45.70 ab 4.58 a 4.79 a 11.60 a 13.30 a
Means with the same letter are not significantly different
Table 2 Influence of sulphur addition on sulphur uptake (kg/ha) by onion
Sulfur levels Uptake by leaves Uptake by bulbs Total uptake Available sulphur status (ppm)
(kg S /ha) 2008-09 2009-10 2008-09 2009-10 2008-09 2009-10 2008-09 2009-10
0 1.11 abc 0.83 bc 16.00 c 12.42 c 17.11 d 13.25 d 13.50 bc 14.39 a
7.5 0.82 c 0.66 c 18.76 bc 14.67 c 19.58 cd 15.33 c 12.87 c 13.81 a
10 1.04 bc 0.97 bc 20.60 bc 15.76 c 21.57 bc 16.73 bc 15.17 abc 15.31 a
20 0.99 bc 0.91 bc 21.64 ab 16.46 bc 22.55 abc 17.37 b 14.33 bc 15.84 a
30 0.94 bc 0.99 bc 21.93 ab 17.61 ab 22.87 ab 18.60 ab 15.50 abc 16.08 a
40 1.26 ab 1.23 ab 22.30 ab 19.33 a 23.56 ab 20.55 a 15.78 ab 15.53 a
50 1.62 a 1.46 a 23.20 a 18.65 a 24.72 a 20.12 a 17.22 a 17.17 a
Means with the same letter are not significantly different
1088 [Indian Journal of Agricultural Sciences 83 (10)
Total soluble solids and pyruvic acid
In the present study, application of sulphur enhanced the
pyruvic acid content of onion bulbs (Table 1). TSS was not
significantly influenced by sulphur application. Low pyruvic
acid content of 3.20 µ moles/g fresh weight was registered in
control where no sulphur was added. Pyruvic acid content
increased with increasing the sulphur level up to 50 kg/ha in
both the years. The previous studies indicated that the
pungency level significantly increased with increasing the
sulphur level in low sulphur soils (Qureshi and Lawande
2006). However, increasing the sulphur level to 30, 40 and
50 kg sulphur/ha increased the pyruvic acid content slightly.
The present study showed that rate of increase in pyruvic
acid content declined with increasing sulphur level.
Sulphur uptake
Sulphur uptake in leaves and bulbs were increased
significantly with increasing the sulphur levels up to 50 kg/
ha (Table 2). Among the different levels of sulphur, application
of 7.5 kg S/ha registered lower total sulphur uptake whereas
maximum was recorded with application of 50 kg sulphur/
ha. Increase in sulphur uptake decreased with increasing
sulphur administration. Lee et al. (2009) observed that the
increase in sulphur content in bulbs was restricted to addition
of sulphur up to 13 kg/ha. The decrease in response to
additional sulphur supply could be due to the supply of
sulphur partly through the native soil sulphur and irrigation
water.
Storage loss
The results of storage loss revealed that sulphur
application to onion crops did not show significant effect on
storage life (Fig 1). The storage losses of onion bulbs after
five months ranged from 30-42%. Among the treatments,
control plots recorded comparatively lower storage losses as
88
THANGASAMY ET AL.
treatments (Table 2). Application of sulphur beyond 20 kg/
ha to onion successively for two years increased the soil
available sulphur levels slightly over the initial sulphur level.
Besides external sulphur application, irrigation water has
also contributed for soil sulphur (17 ppm). Lowest soil sulphur
level after onion harvest was recorded in control plot and
those receiving 7.5 kg S/ha. The decrease in sulphur content
could be due to the removal of sulphur by onion crops. Yoo
et al. (2006) showed that soil sulphur content of 18 ppm was
sufficient for normal onion production.
Marketable bulb yield
Marketable bulb yield was significantly increased with
higher application of compared to control. (Table 1). However,
no significant difference was observed between sulphur
treatments. Marketable bulb yield increased up to 20 kg S
application beyond which it was not significant. The results
of the studies by Qureshi and Lawande (2006) revealed that
onion yield increased with increasing sulphur nutrition level
up to 75 kg/ha in low sulphur soils (<10 ppm S) while no
increase was recorded in soils having high sulphur levels
(Yoo et al. 2006). Critical limit of CaCl2 (0.15 %) extractable
sulphur in soil is 10 ppm below which the soil are deficient
in sulphur (Pasricha and Sarkar 2002). S levels low enough
to reduce onion yield and pungency likely range between 5
and 10 ppm (Yoo et al. 2006). Whereas, the soil available
sulphur content of the experimental fields of present study
was ranged from 12-17 ppm which was in sufficiency level.
This could be the reason for decrease in response by onion
crop to the additional sulphur beyond 20 kg S. Similar results
were also recorded by Jaggi and Raina (2008) who found
that application of sulphur @ 30 kg/ ha recorded significantly
higher bulb yield and further increasing the level to 45 kg/ha
decreased the bulb yield in soils having sufficient sulphur
(13 ppm) at Palampur.
Fig 1 Influence of sulphur application on cumulative storage losses (%) of onion
1089October 2013]
89
EFFECT OF SULPHUR NUTRITION ON PUNGENCY AND STORAGE LIFE OF SHORT DAY ONION
compared to sulphur treatments. The storage losses up to 120
days were about 15-20 % and 22-27 % during 2008-09 and
2009-10 respectively. The storage losses were almost doubled
and maximum loss was recorded during 120-150 days. The
increase in loss was mainly due to rooting of onion bulbs.
The rooting of bulbs was mainly due to the increase of
atmospheric relative humidity. This clearly showed that the
storage loss was mainly influenced by the genetic and
environmental factors. The sulphur application did not have
significant correlation with storage losses (r2= -0.0828) and
found to be contrary to the findings of Lancaster et al. (2001)
and Qureshi and Lawande (2006) in which application of
sulphur enhanced the storage quality of onion bulbs and in
conformity with Forney et al. (2010) who reported that
sulphur applications did not affect sprouting, root formation,
decay or the development of surface discoloration or mold
during storage.
The present study revealed that the soils with sufficient
sulphur level responded slightly to the sulphur nutrition.
Besides sulphur nutrition, irrigation water (17 ppm) also
contributed sulphur to onion crop. Addition of 20 kg sulphur/
ha to onion crops was sufficient to increase the marketable
bulb yield and pungency levels significantly. Irrespective of
the sulphur level, higher storage losses of onion bulbs were
noticed after five months of storage period. This indicated
that application of sulphur had no significant influence on
storage life of onion bulbs. It is clear from the study that
application of 20 kg S/ha is adequate for attaining higher
yield in soils having sufficient sulphur. Further, addition of
extra sulphur increases the soil sulphur level. Hence, site
specific nutrient application as per crop requirement is most
important to maintain soil health, save the costly fertilizer
inputs and sustain crop production.
REFERENCES
Chesnin L and Yien C H. 1950. Turbidimetric determination of
available sulphates. Proceedings of Soil Science Society of
America 15: 149–51.
Forney C F, Jordan M A, Campbell-Palmer L, Fillmore S, McRae
K and Best K. 2010. Sulphur fertilization affects onion quality
and flavour chemistry during storage. ISHS Acta Horticulturae
877.
Lancaster J E, Farrant J, Shaw M, Boycott B, Brash D and Armstrong
J. 2001. Does sulphur supply to the bulb affect storage of
onions. ISHS Acta Horticulturae 555: 111–5.
Lee E J, Yoo K S, John J and Patil B S. 2009. Application of extra
sulphur to high-sulphur soils does not increase pungency and
related compounds in short day onions. Scientia Horticulturae.
123 (2):178–83.
McCallum J, Porter N, Searle B, Shaw M, Bettjeman B and
McManus M. 2005. Sulfur and nitrogen fertility affects flavour
on field-grown onions. Plant and Soil. 269: 151–8.
Pasricha N S and Sarkar A K. 2002. Secondary nutrients. (In)
Fundamentals of Soil Science, pp 384. Sekhon G S, Chhonkar,
P K, Das D K, Goswami N N, Poonia S R, Rattan R K and
Seghal J (Eds). Indian Society of Soil Science.
Qureshi A A and Lawande K E. 2006. Response of onion (Allium
cepa) to sulphur application for yield, quality and its storability
in S-deficient soils. Indian Journal of Agricultural Sciences.
76(9): 535–7.
Raina S K and Jaggi R C. 2008. Effects of sulphur in presence and
absence of farmyard manure on onion (Allium cepa) under
onion-maize (Zea mays) cropping sequence. Indian Journal of
Agricultural Sciences 78(8): 659–62.
Schwimmer S and WestonW J. 1961. Enzymatic development of
pyruvic acid in onion as a measure of pungency. Journal of
Agricultural Food Chemistry 9: 301–4.
Yoo K S, Pike L, Crosby K, Jones R and Leskovar D. 2006.
Differences in onion pungency due to cultivars, growth
environment, and bulb sizes. Scientia Horticulturae 110 : 144–9.
... Several field experiments have been conducted to evaluate the effects of S application on S uptake, yield, and quality of various crops (Hamilton et al., 1997;Thangasamy et al., 2013;Shivay et al., 2014). In garlic, the application of S increases the yield (Jaggi and Raina, 2008;Zaman et al., 2011;Marsic et al., 2019), S uptake, and alliin concentration (Bloem et al., 2010;Marsic et al., 2019). ...
... The positive relationship observed between the pyruvic acid concentration and S dose in the present study explains increased pyruvic acid concentration with S fertilization. Similar positive relationship between pyruvic acid and S dose was reported in our previous study in onion (Thangasamy et al., 2013). However, the effect of S fertilization on these compounds depends mainly on the available concentration of S in the soil. ...
Article
In the present study, three field experiments were conducted to study the effect of sulfur (S) fertilization on yield and biochemical quality of garlic as well as S uptake and thiosulfinate concentration in garlic during the period 2014-17. The experiment consisted of six S treatments (0, 15, 30, 45, 60 and 75 kg S ha−1), and each treatment was replicated four times. The yield, total protein concentration, concentrations of allicin and other thiosulfinate, and antioxidant activity were increased at S doses of 15, 30, and 45 kg ha−1, however, a decline was observed in the aforementioned parameters at 60 kg ha−1 and 75 kg ha−1. At doses 60–75 kg ha–1, S uptake increased whereas the nitrogen-to-sulfur ratio decreased. The concentrations of total protein, allicin, pyruvic acid, and total phenol increased significantly with S application in 2015-16 compared to those in 2014-15 and 2016-17, and the percentage increase varied from year to year. The concentrations of pyruvic acid, total S, allicin and other thiosulfinates, and total polyphenol exhibited strong positive relationships with the dose of S, although the higher yields did not necessarily increase with the S dose. Consequently, a judicious application of S is required to increase the yield and improve the quality of garlic.
... The minimum amount of S requirement for 80% leaf biomass production of A. vera was estimated to be 21.1 kg ha À1 ( Figure 5). Previously, Thangasamy et al. (2013) reported significantly increased bulb yield and pungency levels of onion with the application of 20 kg S ha À1 . Application of fertilizer, field or pot conditions and the choise of crops are the vital factors influencing the S requirements (Maniruzzaman et al., 2016). ...
Article
Full-text available
Sulphur plays a vital role in the formation and biosynthesis of protein, chlorophyll, and few amino acids. To investigate the effect of sulphur fertilizer on leaf biomass yield, critical sulphur concentration, sulphur requirement and uptake by Aloe vera L., a pot experiment was carried out following completely randomized design with six levels of sulphur viz., 0, 15, 30, 45, 60 and 80 kg ha À1 with three replications. The results of the study revealed that the growth attributes, leaf and gel yield, and sulphur uptake significantly improved with sulphur application and the best results were obtained from the application of 45 kg sulphur ha À1. On average, addition of sulphur enhanced the leaf biomass yield by 47.5% and sulphur use efficiency by 38% compared to control. The effect of sulphur on the growth parameters and their significant and positive correlations with yield signifies the importance of sulphur on the yield and quality of A. vera. The calculated minimum amount of sulphur for 80% leaf biomass production was 21.1 kg sulphur ha À1 with a critical leaf sulphur concentration of 0.23% in A. vera. Moreover, sulphur addition to soil substantially enhanced the economic returns of A. vera. Therefore, addition of 45 kg sulphur ha-1 could be a better option for obtaining higher yield and economic return of A. vera.
... The highest pyruvic acid was registered by T 3 that was on a par with T 5 . The increase in pyruvic acid (pungency) with the use of biofertilizer treatments may be due to their effect in increasing sulphur availability to plants as many previous studies have reported positive correlation between the two (Thangasamy et al. 2013, Thangasamy andlawande 2015). The interaction To, Control; T 1 , Azotobacter sp. ...
Article
Full-text available
An experiment was conducted in a factorial randomized block design during rabi 2016-18 at ludhiana. There were 14 treatments consisting of two factors. Factor i comprised two levels of inorganic fertilizers [100% rDF (recommended dose of inorganic fertilizers) and 75% rDF] and factor ii consisted of six combinations of biofertilizers along with a control. The data pooled over years revealed that the utilization of various biofertilizers significantly improved the plant height, number of leaves, 20-bulb weight, bulb equatorial diameter and yield over control at both levels of inorganic fertilizers. however, the per cent increase over their respective control was higher when these biofertilizers were used with 75% RDF than with 100% RDF. Biofertilizer treatments significantly improved the ascorbic acid, total soluble solids and pyruvic acid of bulbs, reduced the physiological loss in bulb weight during storage but the differences in bulb dry matter and ash content were non-significant. The effects of all biofertilizers on soil chemical and microbiological properties were beneficial but non-significant. Two treatments, i.e. 100% RDF + T 6 (Azotobacter + Sphingobacterium + Burkholderia) and 100% RDF + T 1 (Azotobacter + Bacillus) that exhibited 11.5% and 8.6% increment in bulb yield over control (100% RDF) have been identified. Besides, three treatments, i.e. 75% RDF + T 6 , 75% RDF + T 1 and 75% RDF + T 5 (Azotobacter + Bacillus + Burkholderia) registered 8.3%, 7.8% and 7.3% higher bulb yield over control (100% rDF) and therefore may be recommended to save 25% inorganic fertilizers.
... It was found that pyruvic acid was least in control plot with no sulphur application and increased linearly upto 40 and 50 kg ha -1 and decreased with 60kg ha -1 sulphur application. Forney et al., (2002) and Thangasamy et al., (2013) also find that the pyruvic acid content had significant and positive correlation with sulphur application. Maximum pungency was reported with sulphur application of 60kg ha -1 (Channagaoudar and Janawade, 2006), 65 kg ha -1 (de Souza et al., 2015), 75kg ha -1 (Quereshi and Lawande, 2006), 160kg ha -1 (Shakirullah et al., 2002).Total soluble solids (TSS) is an important biochemical parameter that determines quality of onion. ...
Article
Full-text available
Onion is a very important commercial vegetable crop in the kitchens of India. Sulphur is an important nutrient that affects the yield and quality of onion. Keeping this in view an experiment was conducted to study the effect of graded levels of sulphur on yield and quality of onion at Horticultural Research Farm of Institute of Agriculture, Visva-Bharati, Sriniketan, India. The treatments consisted seven incremental doses of sulphur viz. 0, 10, 20, 30, 40, 50 and 60 kg S ha-1 as magnesium sulphate in a randomized block design with three replications. Yield attributes responded favourably to the sulphur application in the range of 40-50 kg ha-1. Maximum bulb yield (28.52 t ha-1) of onion was recorded with 40 kg S ha-1. Nutrient uptake by bulb was also found maximum in the sulphur application of 40 kg ha-1. Maximum pyruvic acid, reducing sugar and total sugar was registered in application of sulphur @ 40 kg ha-1, 40-50 kg ha-1 and 60 kg ha-1 respectively. Total soluble solids (TSS) did not have any significant variation among the treatments. Results revealed that onion responded well with sulphur as magnesium sulphate and application of sulphur @40 kg S ha-1 is helpful in augmenting the higher productivity and better quality of onion in sulphur deficient red and lateritic soils of West Bengal, India.
... (40 kg ha ) as against 50 kg ha in 100% RDF. Previous studies have also showed that increasing the sulphur level increased the pyruvic acid content of onion bulbs (Qureshi and Lawande 2006;Thangasamy et al. 2013). ...
Article
Full-text available
A field experiment was conducted to evaluate the effect of integrated nutrient management modules on garlic yield, nutrient uptake and pungency during 2011-12 and 2012-13. The experiment consisted of nine treatments with three replications in randomized block design. Application of inorganic fertilizer with Farm Yard Manure (FYM), Vermi Compost (VC) amd Poultry Manure (PM) increased garlic yield by 6.5-7.9 per cent compared to inorganic fertilizers alone and 9.9-11.2 per cent over single source of organic manure, biofertilizers, and inorganic fertilizers. Pyruvic acid content was higher in the plots receiving integrated use of inorganic fertilizers and organic manures. Biofertilizers increased soil organic carbon and maintained soil fertility compared to pre-planting soil test values. INM treatments had higher levels of nutrient uptake than the treatments receiving inorganic fertilizers alone. The result indicated that the farmers could save 25 per cent inorganic fertilizers and organic manures by integrating inorganic fertilizers, FYM with VC or PM, or by integrating inorganic fertilizers, FYM, VC, and PM.
... tion. The previous studies indicated that the pungency level significantly increased with increasing the sulphur level in low sulphur soils (Qureshi and Lawande, 2006). Low pyruvic acid content of 3.20 µ moles g -1 fresh weight was registered in control treatment. Pyruvic acid content was increased with increasing sulphur level up to 50 kg S ha -1 (Thangasamy et. al. 2013). Zeinani et al., (2010) reported that the sulphur had positive effect on the pyruvic acid of the onion bulbs. Increasing the level of sulphur up to 150 kg ha -1 resulted in increase of pyruvic acid of the bulbs. The present study showed that rate of increase in pyruvic acid content declined with increasing sulphur level. ...
... Storage of onion, essential to fulfill offseason demand, export and processing is a serious problem in India. Sulphur application increased the shelf life of onion (Thangasamy et al., 2013). ...
... Control and sulphur application at 10 to 30 kg ha -1 and 60 kg ha -1 was found statistically at par with each other. Thangasamy et al. (2013) also find that the pyruvic acid content had significant and positive correlation with sulphur application. ...
Article
Full-text available
An experiment was conducted to study the effect of sulphur application on growth, yield and quality of onion at Horticulture Farm of Institute of Agriculture, Visva-Bharati, Sriniketan. The treatments consisted of six incremental doses of sulphur application (10, 20, 30, 40, 50 and 60 kg ha-1) and no sulphur application (control, 0 kg S ha-1). Treatments were arranged in Randomized Block Design with three replications. Yield, yield attributes and most of the other traits of onion (Agrifound Dark Red) response favourably to the sulphur application in a range of 40 to 60 kg ha-1. Graded level of sulphur application linearly increased the yield up to 50 kg ha-1 with bulb yield of 35.5 tonnes. Maximum pyruvic acid content in onion bulbs was noticed with sulphur application at 40 and 50 kg ha-1. However, application of sulphur did not affect number of scales and TSS content of onion bulb.
... Control and sulphur application at 10 to 30 kg ha -1 and 60 kg ha -1 was found statistically at par with each other. Thangasamy et al. (2013) also find that the pyruvic acid content had significant and positive correlation with sulphur application. ...
Article
Full-text available
An experiment was conducted to study the effect of sulphur application on growth, yield and quality of onion at Horticulture Farm of Institute of Agriculture, Visva-Bharati, Sriniketan. The treatments consisted of six incremental doses of sulphur application (10, 20, 30, 40, 50 and 60 kg ha-1) and no sulphur application (control, 0 kg S ha-1). Treatments were arranged in Randomized Block Design with three replications. Yield, yield attributes and most of the other traits of onion (Agrifound Dark Red) response favourably to the sulphur application in a range of 40 to 60 kg ha-1. Graded level of sulphur application linearly increased the yield up to 50 kg ha-1 with bulb yield of 35.5 tonnes. Maximum pyruvic acid content in onion bulbs was noticed with sulphur application at 40 and 50 kg ha-1. However, application of sulphur did not affect number of scales and TSS content of onion bulb.
Article
The present study was conducted on onion variety ‘Punjab Naroya’ in a factorial randomized block design during 2016−17 and 2017−18 in a loamy sand alluvial soil of semi-arid region. There were 14 treatments consisting of two factors. Factor I comprised two levels of mineral fertilizers (100% NPK and 75% NPK) and factor II consisted of six combinations of microbial inoculants along with a control. Microbial inoculants were applied through root dipping of seedlings for 30 min before transplanting. The study was aimed to identify microbial consortia that can reduce the use of mineral fertilizers by 25% without any loss in bulb yield and to identify microbial consortia that can act as potential supplement to recommended dose of mineral fertilizers (100% NPK) in improving bulb yield of onion. We have identified two treatments viz., 100% NPK + T6 (Azotobacter sp. + Sphingobacterium sp. + Burkholderia sp.) and 100% NPK + T1 (Azotobacter sp. + Bacillus sp.) that have registered 12.0% and 7.5% increase in bulb yield over uninoculated control (100% NPK). The study has also led to the identification of three treatments viz., 75% NPK + T6, 75% NPK + T1 and 75% NPK + T5 (Azotobacter sp. + Bacillus sp. + Burkholderia sp.) manifesting 8.6%, 6.1% and 3.7% higher bulb yield over uninoculated control (100% NPK). Besides, various microbial inoculants significantly improved the plant growth parameters (plant height, number of leaves), yield attributes (bulb yield, 20-bulb weight and equatorial diameter of bulb), bulb quality attributes (ascorbic acid, total soluble solids, pyruvic acid and dry matter) and reduced the physiological loss in weight during 15–120 days of storage at room temperature. The triple inoculation treatment with Azotobacter sp. + Sphingobacterium sp.+ Burkholderia sp. gave the best results for most of the traits followed by dual inoculation treatment with Azotobacter sp. + Bacillus sp. However, the soil chemical (pH, electrical conductivity, organic carbon, available nitrogen, phosphorus and potassium) and microbial properties (bacterial, actinomycetes and fungal count) exhibited non-significant improvement after harvest of onion crop. The interaction effects between mineral fertilizers and PGPRs were non-significant for all the traits. Therefore, it can be concluded that the integrated utilization of these microbial inoculants as root dip of seedlings along with 75% NPK offers the scope of reducing the application of mineral fertilizers to onion crop by 25% without any loss in bulb yield and to reduce environmental pollution.
Article
Full-text available
Field experiment conducted during 2003-06 to study the effects of 4 (0, 15, 30 and 45 kg/ha.) S levels in the absence and presence of 25 tonnes farmyard manure/ha in onion (Allium cepa L.) - maize (Zea mays L.) system. The results show the positive effects of 30 kg S/ha on bulb yield over the previous levels of 0 and 15 kg/ha (direct effect). Addition of sulphur beyond 30 kg/ha brought the yield to the level of 0 and 15 kg/ha. Application of farmyard manure @ 25 tonnes/ha significantly increased bulb and foliage yield. Sulphur-farmyard manure interaction was positive at low and negative at higher levels of S. Highest yield (yield) was observed either in treatment combination of 25 tonnes farmyard manure/ha without S or 30 kg S/ha without farmyard manure. Plant height significantly increased only by farmyard manure (from 57.4-59.1 cm) over without farmyard manure. In maize (residual effect) and also in onion-maize sequence as a whole (direct + residual effects) the same trend was visible except that the sulphur-farmyard manure interaction was significant only in the later. Sulphur addition beyond 30 kg/ha brought down the total economic yield and also the foliage yield of both the crops to the level of either 15 kg S/ha or even control.
Article
An experiment was conducted on onion (Allium cepa L) during late kharif season (locally known as rangda) in 2001-02 and 2002-03 at Rajgurunagar in Pune district of Maharashtra. The effect of sulphur application on 'B 780' onion on its yield, quality and storability was studied. Sulphur was applied as elemental sulphur 15-75 kg/ha along with N (100 kg/ha), P (50 kg/ha) and K (50 kg/ha). Onion responded significantly to sulphur @ 30-75 kg/ha over only NPK. The highest bulb yield 39.1 tonnes/ha with 75 kg/ha was recorded. Sulphur content in bulbs was increased by 48.0% due to 75 kg S/ha over only NPK treatment. Pyruvic acid concentration increased from 3.3 μ mol/ml with 75 kg S/ha. Storage losses were reduced by 10.4% over a period of 6 months storage due to application of S @ 45 kg S/ha in comparison to only NPK treatment. Simple linear regression analysis revealed significant negative correlation between the storage losses of onion bulbs taken as dependent variable and pyruvic acid and total soluble solids as independent variables.
Article
Sulfur fertilization of onions in the field can increase yield and bulb size, but reports of its effect on storage life and flavor chemistry have been varied. To clarify these effects, 2 cultivars of yellow cooking onions, 'Frontier' and 'Prince', were grown in 4 fields by 2 commercial producers during 3 growing seasons. Prior to planting, two sources of sulfur, langbeinite (K2Mg2(SO4)3) and potassium sulfate (K2SO4), were incorporated into the onion beds at rates of 0, 30, or 50 kg/ha of S. Onions were harvested by hand, cured, and stored in 2 commercial common storage facilities. Samples of onions were evaluated for quality after 4, 8, 12, and 16 weeks of storage and for total S and S-metabolites after 4 and 16 weeks. Both sulfur fertilizer treatments increased the sulfur content of both 'Frontier' and 'Prince' onion bulbs by an average of 25%. Associated with the increased sulfur content was an increase in onion pungency/flavor measured as increased pyruvate content in macerated onion tissue and changes in S-alk(en)yl cysteine sulfoxides (ACSO) content. Pyruvate increased an average of 35% in onions receiving S-fertilization compared to controls. Differences decreased during storage as a result of pyruvate content increasing in control onions. The content of propenyl cysteine sulfoxide, the precursor of the tear inducing lachrymatory factor, was 10-fold greater in S-fertilized onions than controls and increased during storage. Methyl cysteine sulfoxide, which contributes to fresh onion odor, decreased during 16 weeks of storage, resulting in a 6.5-fold greater concentration in the S-fertilized onions than controls. Propyl cysteine sulfoxide was 1.2-fold greater in S-fertilized onions than controls. Sulfur fertilization had little effect on onion storage-life. Over three seasons S-fertilization treatments had a minimal effect on soluble solids, titratable acids, and fresh weight loss during storage. Bulb firmness was affected slightly by fertilizer treatments but the variable response among seasons indicates that environmental factors may interact with the effects of S nutrition. Sulfur applications did not affect sprouting, root formation, decay or the development of surface discoloration or mold during storage.
Article
Pyruvic acid appears enzymatically in onion tissue disintegrated by comminution. Over 95% of the maximum amount of pyruvic acid is produced within 6 minutes after the start of comminution. The total amount produced appeared to depend on the generally accepted degree of pungency of the onion lot investigated. Weak onions produced 2 to 4 μmoles, those of intermediate strength 8 to 10 μmoles, and strong onions 15 to 20 μmoles of pyruvic acid per gram of onion. The enzymatic basis of the method, as well as its relation to other methods of estimation of pungency, is discussed.
Article
This study was conducted to determine the effects of genetic and environmental factors on onion pungency, estimated as pyruvic acid levels. Genetically identical clones were grown at three different field locations and in a greenhouse. Onion pungency was significantly influenced by clone type, location, and their interaction. Genetic differences were the major determining factor of onion pungency (81.3% of total variation). Location, including all environmental factors, and the clone × location interaction comprised 11.4% and 7.3% of the total variation, respectively. The magnitude of the pungency difference among field-grown onions was about 1.5 μmol/ml. The pungency levels were not positively correlated with soil sulfur nutrition levels, which ranged from 16 to 97 ppm. Within clones, onion pungency levels were loosely inversely correlated with increasing bulb weight. The clones proved to have the most uniform pungency (8% CV), followed by hybrids (10.6% CV) and open-pollinated cultivars (21.3% CV). We have demonstrated that genetic factors were determinant of onion pungency. Environmental factors influenced pungency to a lesser degree. Therefore, choosing cultivars with low pungency, ideal growing environments and proper sulfur nutrition control, are key factor in producing sweet onions.
Article
Although glasshouse studies have conclusively demonstrated that S nutrition can affect onion (Allium cepaL.) pungency this has been rarely observed in field-based studies due to difficulties in controlling S nutrition and lack of efficient methods for measurement of flavour bioactives. We have developed a rapid automated method for determination of onion lachrymatory factor ((Z, E)-thiopropanal-S-oxide; LF) based on juice extraction into dichloromethane and gas chromatography (GC) analysis with flame photometric detection. We evaluated this in a field trial of a mild (cv. ‘Encore’) and a pungent (cv. ‘Kojak’) onion cultivar grown on a low S soil with and without S addition, under high or low N treatments. No treatments significantly affected bulb fresh weight but S fertilisation significantly increased bulb total S, sulfate, pungency, LF and flavour precursor levels in both varieties. Analysis of bulb flavour precursors by HPLC confirmed that juice LF levels paralleled levels of the flavour precursor S-1-propenyl cysteine sulfoxide. The pungent cultivar also exhibited significant N main effects on bulb LF, total S and sulfate. We also assayed the key S-assimilatory enzyme, APS reductase (APR) in leaves before and during bulbing. Specific activities in the range of 1 to 11nmolmg−1·min−1 were observed in youngest leaves, but only the milder cultivar exhibited significant stage × N × S effects. These findings suggest that sulfur metabolism of mild and pungent onions respond differently to N fertility, and that GC of LF is practical for field-based studies of onion flavour.
Article
Sulfur (S) nutrition has a strong influence on onion pungency, and the production of sweet onions in the high-sulfur soil of Texas is a challenge to growers. This study was performed to determine the effects of S applications to fields already having sufficient levels of soil S on pungency and related compounds in four shortday onion cultivars. The onion cultivars ‘Cougar’, ‘Legend’, ‘Texas Early White’, and ‘Texas Grano 1015Y’ were grown in three commercial fields at Edinburg, Mercedes, and Weslaco of the Rio Grande Valley of South Texas with applications of sulfur at 0, 13, and 26 kg S/ha. Pyruvic acid, bulb weight, extractable S in soil and total S in bulb, soluble solids content (SSC), flavor precursor compounds [also called S-alk(en)yl-l-cysteine-sulfoxides (ACSOs)], and total sugars were measured. The pyruvic acid level of onions was not increased by the S applications and showed no significant correlation with soil S levels in any of the cultivars at locations having 30 or 235 ppm S. The SSC, total S in bulbs, total sugars, and total ACSO content also showed no correlation with the S applications and soil S levels. Onion pungency and content of flavor precursor compounds were significantly influenced by cultivar and cultivar × location interaction. We conclude that onion pungency is not increased by application of extra S fertilizer to commercial fields already containing sufficient levels of soil sulfur.
Secondary nutrients. (In) Fundamentals of Soil Science
  • N Pasricha
  • A K Sarkar
  • G S Sekhon
  • P K Chhonkar
  • D K Das
  • N N Goswami
  • S Poonia
  • R R, Rattan
Pasricha N S and Sarkar A K. 2002. Secondary nutrients. (In) Fundamentals of Soil Science, pp 384. Sekhon G S, Chhonkar, P K, Das D K, Goswami N N, Poonia S R, Rattan R K and Seghal J (Eds). Indian Society of Soil Science.