Effect of Different Levels of Nitrogen and Sulphur on Growth and Yield of Indian Mustard (Brassica juncea L.)

Abstract

Indian mustard (Brassica juncea L.) is an important oilseed crop in India, where its productivity and oil quality are strongly influenced by balanced nitrogen and sulphur nutrition. A field experiment was conducted during the Rabi seasons of 2020–21 and 2021–22 at the Agronomy Research Farm of S.D.J. Post Graduate College, Chandeshwar, Azamgarh (U.P.) to evaluate the effect of nitrogen and sulphur fertilization on growth, yield and yield attributes of Indian mustard (Brassica juncea L.). The experiment consisted of four levels of nitrogen (0, 40, 80 and 120 kg ha⁻¹) and four levels of sulphur (0, 15, 30 and 45 kg ha⁻¹), laid out in a randomized block design with three replications. Results indicated that increasing nitrogen and sulphur levels significantly enhanced growth parameters, including plant height, number of green leaves, branches, fresh and dry weight. Application of 120 kg N ha⁻¹ increased plant height by about 16%, number of green leaves by 56%, and biomass by 13–15% over control. The highest growth values were recorded under 120 kg N ha⁻¹ and 45 kg S ha⁻¹, which were statistically at par or significantly superior to lower treatments. Yield attributes such as number of siliquae per plant, siliqua length and seeds per siliqua also improved significantly with increasing nutrient levels, although the interaction effect (N × S) was non-significant. Maximum seed yield (23.11 and 23.15 q ha⁻¹) and stover yield (78.79 and 79.20 q ha⁻¹) were obtained with 120 kg N ha⁻¹, showing increases of about 45–46% and 40–41% over control, respectively. Sulphur application at 45 kg ha⁻¹ also produced higher yields. The yield improvement may be attributed to enhanced nutrient uptake, improved photosynthesis and better source–sink relationship. The combined application of 120 kg N and 45 kg S ha⁻¹ is optimum for maximizing mustard productivity under eastern Uttar Pradesh conditions.