Sulphur application increases seed yield and oil content in sesame seeds under rainfed conditions

Sulphur (S) plays a significant role in determining seed yield and quality of oilseed crops. However, the effect of sulphur application on yield, sulphur uptake and concentration in sesame genotypes under rainfed conditions is still unclear. A two-year field trial was conducted during 2012 and 2013 to analyze the impact of four sulphur levels S-1, 20 kg ha(-1); S-2, 30 kg ha(-1); S-3, 40 kg ha(-1); S4, 50 kg ha(-1) on capsules per plant (NCP), seeds per capsule (NSC), seed weight (SW), seed yield (SY), total sulphur uptake (TSU), sulphur concentration and quality parameters of four sesame genotypes (G(1), SG-27; G(2), SG-30; G(3), SG-36; G(4), SG-51). The results showed that all the sesame genotypes responded significantly to sulphur application for all the parameters, however, the level of response differed among genotypes. Maximum NCP, NSC, SW, SY, oil yield and superior quality of seeds were observed with G(3). Among all the sulphur levels, S-3 considerably increased the NCP, NSC, SW, seed yield (1529.9 kg ha(-1) for 2012 and 1757.1 kg ha(-1) for 2013), oil content (39.1% in 2012 and 39.4% in 2013) and oil yield (601.3 kg ha(-1) for 2012 and 692.4 kg ha(-1) for 2013) of sesame genotypes. These findings implied that sulphur application has the significant impact on the yield-related parameters and sesame genotypes responded positively to sulphur application. In addition, application of sulphur increased TSU and maximum TSU (39.7 kg ha(-1)) was noticed in G(3) under treatment S-3. The sulphur concentration in stem, leaf, capsule and seed varied significantly among all sesame genotypes. Higher content of sulphur in stem (17.4 mg g(-1)), leaf (10.7 mg g(-1)), capsule (11.4 mg g(-1)) and seed (8.6 mg g(-1)) was observed with G(3) under treatment S3. However, decreasing trends were found for the accumulation of protein content (9.7%), palmitic acid (22.7%), stearic acid (15.2%) and linoleic acid (6.3%) while the accumulation of oleic acid (7.6%) was significantly increased from S-1 to S-4. These results suggested that by selecting the appropriate genotype and level of sulphur for sesame crop we can increase the seed yield and quality characters of sesame seeds under rainfed conditions.