Abstract: A field experiment was conducted in sandy clay loam soils to study the importance of sulphur in realizing the better yield and quality viz., crude protein and oil content and yield of sesame crop during summer season of 2005 in Randomized Block Design with three replications. Three sesame varieties (TMV 4, TMV 6 and KS 95010) were tested for the response to five levels of sulphur (S0: 0 kg S ha-1; S15: 15 kg S ha-1; S30: 30 kg S ha-1; S45: 45 kg S ha-1 and S60: 60 kg S ha-1). The positive response between S application up to 60 kg ha-1 and growth and yield components and seed yield of sesame was noticed in this study. The plant height was superior with the application of 60 kg S ha-1 and TMV 6 recorded the maximum and the highest was in KS95010 with the application of 60 kg S ha-1. The number primary and secondary branches per plant, number of capsule in main stem, primary and secondary branch and number of seeds per capsule was found higher with the application of 45 kg S ha-1. Application of 60 and 45 kg S ha-1 recorded higher seed yield and KS 95010 was significantly superior to other varieties. The highest seed yield was obtained from KS 95010 with the application of 60 kg S ha-1. The quality parameters studied viz., crude protein content and oil content and yield was increased with increasing S levels. The crude protein content was higher with higher levels of S viz., 45 and 60 kg S ha-1 and TMV 4 registered the highest crude protein content among the varieties. The higher crude protein content was obtained in TMV 4 with the application of 60 and 45 kg S ha-1. The oil content was highest with the application 60 kg S ha-1 and higher in TMV 4 and TMV 6 than KS 95010. The higher oil content was obtained in TMV 4 with the application of 60 kg S ha-1. The oil yield was also recorded higher at 60 kg S ha-1 and all the varieties were equally effective. The higher oil content was obtained in KS 95010 with the application of 60 kg S ha-1. In general application of 45 and 60 kg S ha-1 was found to improve higher growth, yield and quality in different sesame cultivars. The culture KS 95010 performed better than the other varieties.
INTRODUCTION
Sesame is called as Queen of oilseeds. Oilseeds are important constituent in human dietary system next to carbohydrate and protein (Pal and Gangwar, 2004). Among the oilseeds crops, sesame has the highest oil content of 46-64% with 25% protein (Goel and Sanjayakumar, 1994). Sulphur (S) requirement is equal to that of phosphorus (Scherer, 2001) essential for the growth and development, plays a key role in the plant metabolism, indispensable for the synthesis of essential oils, plays a vital role in chlorophyll formation (Ajai Singh et al., 2000) required for development of cells and it increases cold resistance and drought hardiness (Patel and Shelke, 1995) and constituent of a number of organic compounds (Shamina and Imamul, 2003), oil storage organs particularly oil glands (Jaggi et al., 2000) and vitamin B1 (Thirumalaisamy et al., 2001).
At present, the average yields of seeds are just about 421 kg ha-1, which needs to be increased to at least 1.2 and 1.5 tones by 2010 and 2015 as reported by Hedge (2005). The growth parameters like leaf area, crop growth rate and net assimilation rate index and yield parameters like branches per plant, capsules per plant, seeds per capsule and 1000 seed weight was improved increased sulphur in sesame (Thakur and Patel, 2004; Sarkar and Panik, 2002; Tiwari et al., 2000). The response of sesame to sulphur for producing higher yield was up to 40 kg ha-1 according to Nagwani et al. (2001) and Kathiresan (2002) and up to 50 kg ha-1 (Sarkar and Panik, 2002). Sulphur application not only improved the grain yield but also improved the quality of crops (Tiwari and Gupta, 2006). At present, the average yields of seeds are just about 421 kg ha-1, which needs to be increased to at least 1.2 and 1.5 tones by 2010 and 2015 as reported by Hedge (2005). The response of sesame to sulphur for producing higher yield was up to 40 kg ha-1 according to Nagwani et al. (2001) and Kathiresan (2002) and up to 50 kg ha-1 (Sarkar and Panik, 2002). The response of sesame crop varies with sulphur levels to produce crude protein and oil content and yield was reported by Singh and Tiwari (1985). As the intensity of cropping is gradually increasing, the response of oilseeds to sulphur is also increasing (Ghosh et al., 2002). Use of high analysis sulphur free fertilizers, heavy sulphur removal by the crops under intensive cultivation and neglect of sulphur replenishment contributed to widespread sulphur deficiencies in arable soils. Hence this study was attempted to study the importance of sulphur in realizing the better growth, yield and quality of sesame crop.
MATERIALS AND METHODS
Experimental Site, Design and Treatment Details
The experiment was conducted in a sandy clay loam soil of Pandit Jawaharlal
Nehru College of Agriculture and Research Institute, Karaikal, Union Territory
of Pondicherry, India during the year 2004-05. The experimental site is situated
12 km from Bay of Bengal, lies between 10°49' and 11°01’ North
latitude and 78°43’ and 79°52’ East longitude with an altitude
of 4 m above Mean Sea Level (MSL). The initial soil analyses show that the soil
was sandy clay loam in texture falls in Fluventic Haplustept taxonomic
class. The soil is optimum in bulk density (1.25 Mg m-3) and particle
density (2.20 Mg m-3) with the porosity of 43.18%. The soil reaction
was neutral (pH: 7.61) and the Electrical Conductivity is low (0.35 dS m-1).
The soil was low in available nitrogen (KMnO4-N: 146 kg ha-1)
and available potassium (NH4OAc-K: 145 kg ha-1), medium
in available phosphorous (Olsen-P: 12.6 kg ha-1) and high in organic
carbon content (0.88%). The sulphur content was 16.9 kg ha-1.
The experiment was conducted during summer season between March and June of the year 2005 in Randomized Block Design (RBD) with three replications. Three sesame varieties (TMV 4, TMV 6 and KS 95010) were tested for the response to five levels of sulphur (S0: 0 kg S ha-1; S15: 15 kg S ha-1; S30: 30 kg S ha-1; S45: 45 kg S ha-1 and S60: 60 kg S ha-1). The sulphur (S) was supplied through Gypsum as per the treatments to the corresponding plots. The nitrogen was supplied through Di-Ammonium Phosphate (@ 35 kg N ha-1) in three splits half at basal and remaining half in two equal splits at vegetative stage and at flower initiation stage; Phosphorous (@ 23 kg P2O5 ha-1) was supplied through Di-Ammonium Phosphate as basal; potassium (@ 23 kg K2O ha-1) through muriate of potash as basal. Thinning was done twice at 15 and 30 days after sowing. A hand weeding was done at 25 days after transplanting to remove the competitive weeds in the field. A pesticide spray of monocrotophos @ 250 mL ha-1 was given at 30 days after transplanting to control leaf folders and sucking pests. The plant height, number of branches per plant, number of capsules per plant, number of seeds per capsule was recorded at harvest stage. The crop was harvested separately from the plots, harvested and winnowed and grain yield and test weight were recorded. The nitrogen content of seeds was estimated by Kjeldahl's method by 1030 auto analyzer (Bremner, 1965) and crude protein content was derived by multiplying the seed nitrogen content with the factor 6.25 (Humphries, 1956). The oil content was estimated by Soxhlet apparatus method following the procedure of Singh et al. (1960). The oil yield was calculated by multiplying oil content with seed yield. The observations collected from the experiment and the data on the results of analysis of plant samples were subjected to statistical scrutiny as per the procedure of Gomez and Gomez (1984).
RESULTS AND DISCUSSION
Effect of Sulphur on Growth Parameters
Plant Height
Plant height at harvest stage increased with increased S levels. This might
be due to more synthesis of amino acids, increase in chlorophyll content in
growing region and improving the photosynthetic activity, ultimately enhancing
cell division and thereby increased the crop growth rate (Table
1). This was evinced through the studies of Intodia and Tomar (1997) and
Dubey and Khan (1993). Application of 60 kg S ha-1 recorded highest
plant height of 140.9 cm among the S levels and in varieties TMV 6 recorded
the maximum. Higher dose of 60 kg S ha-1 to KS 95010 produced highest
height (144.7 cm).
Number of Branches per Plant
Application of 45 kg S ha-1 produced more primary (8.4) and secondary
(8.1) branches per plant (Table 1). Primary and secondary
branches per plant indicated that sulphur application increased the number.
These findings are in line with the result obtained through the study of Vishwakarma
et al. (1998). The increased number of branches by sulphur application
is attributed to the stimulatory effect of sulphur in cell division. The importance
of sulphur in cell division, cell elongation and setting of cell structure has
been reported by Hadvani et al. (1993). Among the varieties TMV 6 produced
more number of primary and secondary branches of 8.5 and 7.3 per plant, respectively.
Effect of Sulphur on Yield Parameters
Number of Capsules per Plant
Application of S significantly increased the number of capsules per plant
in main stem, primary branches and secondary branches (Table 1).
Similar results were reported by Devakumar and Giri (1998) and Subramaniyan
et al. (1999). Among the different S levels, application of S at 45 kg
ha-1 recorded higher number of capsules in main stem, primary and
secondary branches per plant. Beyond this level, there was a decline in the
number of capsules per plant. The possible reason for this kind of result may
be due to the nutritional imbalance caused by the highest level of S i.e., 60
kg ha-1. Among the varieties tested, KS 95010 produced higher number
of capsules in both primary and secondary branches of plants. The promising
performance of KS 95010 in producing higher number of capsules per plant was
well-established through the study of Govindarasu et al. (1998).
Number of Seeds per Capsule
Positive relationship was observed between the levels of sulphur and the
number of seeds per capsule. Among the different S levels, application of S
at 45 kg ha-1 recorded higher number of seeds per capsule (48.3)
(Table 1). Enhanced performances of reproductive parameters
was due to the role of S in better absorption of nutrients and also due to higher
rate of assimilate partitioning towards the sink. These findings are in conformity
with those reported by Devakumar and Giri (1998) and Subramaniyan et al.
(1999), who observed that the application of sulphur significantly influenced
the yield components in sesame.
| Table 1: | Influence of Sulphur levels on growth and yield components and seed yield of sesame varieties |
| NS: Non Significant | |
All the varieties showed variation in increasing the number of seeds per capsule with sulphur application. Among the S levels, 45 kg S ha-1 recorded the highest number of seeds per capsule in the case of TMV 4 and TMV 6, whereas number of seeds was increased up to 60 kg S ha-1 in the case of KS 95010. Here again, the culture KS 95010 is proved to be more fertilizer responsive as claimed by Govindarasu et al. (1998).
Test Weight
The test weight was significantly superior in 60 kg S ha-1 than
the other levels compared, but was not much conspicuous (Table
1). Among the varieties, TMV 4 recorded higher test weight. However, the
differences were not that much conspicuous.
| Table 2: | Sulphur application on seed yield and quality of sesame varieties |
| NS: Non Significant | |
This might be attributed to the intrinsic characters of the varieties. This finds support from Prabhu (2004).
Effect of Sulphur on Seed Yield
The effect due to S levels, varieties and their interactions was seen very
conspicuously in realizing the seed yield (Table 2). Among
the different S levels compared 45 and 60 kg S ha-1 recorded the
highest seed yield of 601 and 587 kg ha-1, respectively. With respect
to the varieties, the highest yield (548 kg ha-1) was recorded in
KS 95010 with, followed by TMV 6 and TMV 4. Application of 60 kg S ha-1
to KS 95010 produced highest seed yield of 617 kg ha-1 but it was
comparable with the yield of TMV 6 (610 kg ha-1) with 45 kg S ha-1.
Supply of S in addition to N, P and K might act as a lifting factor behind the
increased seed yield. Application of sulphur resulted in improved growth and
yield parameters and therefore, finally increased the seed yield. These findings
are in accordance with the earlier reports of Devakumar and Giri (1998) and
Tiwari et al. (2000). The lowest yield recorded under control treatment
might be due to the limited availability of nutrient in soil and uptake of nutrient
by the crop, which ultimately reflected on these results. This finds support
from the study of Singh et al. (1997) and Ansari et al. (1998).
The interaction of S with varieties revealed that, application of S at 60 kg
ha-1 performed better in KS 95010 (617 kg ha-1) which
was followed by TMV 6 and TMV 4, respectively at 45 kg S ha-1 and
the lower yields in the variety of TMV 4 at different levels of S are ascribed
due to their intrinsic characters and growth potential (Govindarasu et al.,
1998).
The Response Function and Optimization of Sulphur
Response function between levels of S and seed yield of varieties were characterized
by quadratic relationship. The results indicated that the physical optimal rate
was 41.25 kg S ha-1 for TMV 4, 48.74 kg S ha-1 for TMV
6, 56.25 kg S ha-1 for KS95010 and as a whole 47.27 kg S ha-1
for sesame. The economic optimal rate was 40.32 kg S ha-1 for TMV
4, 47.39 kg S ha-1 for TMV 6, 54.66 kg S ha-1 for KS95010
and as a whole 46.09 kg S ha-1 for sesame. From this investigation,
the optimum level of S can be fixed as 48 kg ha-1 for irrigated sesame.
Effect of Sulphur on Quality Parameters
Crude Protein
The crude protein content of seeds was increased with increasing in S levels.
The higher crude protein contents of 23.96 and 22.86% were registered at 60
and 45 kg S ha-1 than the other levels. The lowest content of 16.31
was observed at S control. Among the varieties tested, TMV 4 registered the
highest crude protein content of 23.75% followed by TMV 6 (19.65%). The highest
crude protein of 26.77 and 25.54% was produced by the variety TMV 4 with 60
and 45 kg S ha-1. The substantial increase in crude protein content
with gypsum application might be due to increased availability of sulphur for
subsequent synthesis of oil and crude protein. This kind of interpretation is
in consonance to the report of Chitkala and Reddy (1991).
Oil Content
The oil content of sesame seeds was significantly influenced by S application.
Increasing the S levels increased the oil content considerably (Table
2). This was in line with the reports of FAO (2004). The maximum oil content
of 50.7% was recorded with the highest dose of sulphur (60 kg S ha-1)
and followed by 45 kg S ha-1 (48.7%). This same result was reported
by Singh and Tiwari (1985). This could be attributed to the influence of sulphur
in rapid conversion of nitrogen to crude protein and finally to oil. The acetic
thiolinase, a sulphur based enzyme in the presence of S convert acetyl Co-A
to melonyl Co-A, rapidly resulting in higher oil content in seed crops (Krishnamurthy
and Mathan, 1996). Among the varieties TMV 4 recorded highest oil content of
45.6% and it was on par with TMV 6 (45.0%) but superior than KS 95010 (44.8%).
The highest oil content (51.5%) was recorded by TMV 4 with the application of
60 kg S ha-1. The increase in oil content due to S application might
be due to its key role in biosynthesis of oil in plants (Mudd, 1967).
Oil Yield
Oil yield was significantly influenced by S application. The application
of S at 60 kg ha-1 registered the higher oil yield of 299.6 kg ha-1
(Table 2). Though there were slight variations in the oil
yields among the varieties, it was not significant. However, the interaction
between varieties and S levels showed significant variation in the oil yield.
The higher oil yield of 305 kg ha-1 was registered in KS 95010 at
60 kg S ha-1. Full utilization of carbohydrate for the synthesis
of oil with sulphur might be increased the oil yield (Yadav and Harishankar,
1980).
CONCLUSIONS
The positive response between S application and growth, yield and quality of sesame was noticed in this study. The plant height was superior with the application of 60 kg S ha-1 and TMV 6 recorded the maximum and the highest was in KS95010 with the application of 60 kg S ha-1. The number primary and secondary branches per plant, number of capsule in main stem, primary and secondary branch and number of seeds per capsule was found higher with the application of 45 kg S ha-1. The branching was higher in TMV 6, capsule count in KS 95010 and seeds per capsule with TMV 4 and TMV 6. The seed yield was much influenced by the application of S and among the varieties. At 60 and 45 kg S ha-1 seed yield and KS 95010 was significantly superior. The highest seed yield was obtained from KS 95010 with the application of 60 kg S ha-1. The physical optimal rate was 47.27 kg S ha-1 and economic optimal rate was 46.09 kg S ha-1 for sesame. The higher levels of S viz., 45 and 60 kg S ha-1 recorded higher crude protein content and TMV 4 registered the highest crude protein content among the varieties. The higher crude protein content was obtained in TMV 4 with the application of 60 and 45 kg S ha-1. The oil content of sesame seeds increased conspicuously with increased supply of S. Application 60 kg S ha-1 recorded higher oil content and higher with TMV 4 and TMV 6. The higher oil content was obtained in TMV 4 with the application of 60 kg S ha-1. The oil yield was also recorded higher at 60 kg S ha-1 and all the varieties were equally effective. The higher oil content was obtained in KS 95010 with the application of 60 kg S ha-1. From this investigation, the optimum level of S can be fixed as 48 kg ha-1 for better growth, yield and quality of sesame crop and KS 951010 will be the more suitable varieties.