Effect of sulphur and zinc on growth and yield of Indian mustard (Brassica juncea)

Abstract

A field experiment was conducted to assess the effect of graded levels of sulphur and zinc on the growth, phenology, yield attributes, and yield of Indian mustard (Brassica juncea L.). The study evaluated four levels of sulphur (0, 20, 40, and 60 kg ha⁻¹) and four levels of zinc (0, 2.5, 5.0, and 7.5 kg ha⁻¹) in a factorial arrangement. The results demonstrated that sulphur application significantly enhanced plant height, leaf area index (LAI), number of siliques per plant, seeds per silique, biological yield, seed yield, and stover yield, with maximum values observed at 60 kg S ha⁻¹. Zinc nutrition also significantly influenced these parameters, with the highest levels recorded at 7.5 kg Zn ha⁻¹. Interaction effects between sulphur and zinc were significant for key traits such as plant height, LAI, siliques per plant, and yield, indicating a synergistic relationship. Phenological stages, including days to 50% flowering and maturity, were slightly prolonged with higher nutrient levels but remained statistically non-significant. The harvest index showed minimal variation across treatments. These findings highlight the critical role of balanced sulphur and zinc fertilisation in improving the growth and productivity of mustard. The study confirms that integrated nutrient management, involving optimal sulphur and zinc levels, can effectively enhance both vegetative and reproductive performance in mustard under field conditions.