Interactive effect of sulfur and nitrogen on growth and yield attributes of oilseed crops (Brassica campestris L. and Eruca sativa Mill.) differing in yield potential

Field experiments were conducted to determine the interactive effect of sulfur (S) and nitrogen (N) on growth and yield attributes of oilseed crops [Brassica campestris L. (V1) and Eruca sativa Mill. (V2)] differing in yield potential. Two combinations of S and N (in kg ha-1): 0S + 100N (-S+N;T1) and 40S + 100N (+S+N;T2) were used. Biomass accumulation, leaf area index (LAI), leaf area duration (LAD), and photosynthetic rate in the leaves were determined at various phenological stages. The results showed that the combined application of S and N (+S+N) significantly (P<0.05) improved the growth and yield attributes of both the genotypes compared with N applied alone (-S+N). Genetic variability was observed between the two genotypes in response to combined application of S and N (T2). Genotype V1 had higher biomass accumulation, photosynthetic rate, seed yield, oil yield, biological yield, and harvest index when compared with genotype V2. Treatment T2 resulted in 142, 95, 56, and 349% enhancement in biomass accumulation, leaf-area index (LAI), leaf-area duration (LAD) and photosynthetic rate, respectively in comparison with treatment T1 in genotype V1. Seed yield, oil yield, biological yield, and harvest index were improved by 141, 171, 85, and 30%, respectively, by treatment T2 in comparison with T1. In the case of genotype V2, increase in biomass accumulation, LAI, LAD, and photosynthetic rate due to application of treatment T2 were 156, 137, 125 and 467%, respectively, over the results of T1. Seed yield, oil yield, biological yield and harvest index improved by 193, 251, 98, and 48%, respectively, with this treatment. On the basis of results obtained in this study, it can be concluded that sulfur must be included in the nutrient management package for optimum growth and yield attributes of oilseed crops. Furthermore, the yield potential of oilseed crops with low seed and oil yield can be improved using this treatment as achieved in our study in case of taramira (Eruca sativa Mill.), a genotype with low seed and oil yield.