Influence of phosphorus, sulphur and boron on growth, yield, nutrient uptake and economics of Indian mustard (Brassica juncea) under rainfed conditions

A field experiment was conducted during the winter seasons of 2001-2003 at New Delhi, on deep sandy- loam soil analyzing medium in available P and S, to study the effect of 3 levels of phosphorus (0, 25 and 50 kg P20$ha), 3 levels of sulphur (0, 20 and 40 kg Stha) and 2 levels of boron (control and 0.2% spray of borax at 50% flowering) on rainfed Indian mustard [Brassica juncea (L.) Czernj. & Cosson]. Progressive increase in P and S levels increased yield attributes and seed yield, but the increase in seed yield was significant only up to 25 kg P205/ha and 20 kg Stha. Indian mustard removed more S than P. Owing to P and S levels, P, S and B uptake was significant only up to 25 kg P205 and 20 kg Stha. Seed-yield response to tested levels of P and S was found qua- dratic. Based on the response equation, optimum dose of P20,, responsetkg P and returnstre-investment on P,05 were 45.4 kg P20dha, 10.8 kg and Rs 4.82 respectively. Corresponding figures for S application were 30.9 kg St ha, 13.3 kg seedkg S and Rs 5.63tRe investment on S. Net returns were the maximum with 50 kg P205/ha (Rs .. 19,214tha) and 40 kg Stha (Rs 17,664/ha), whereas benefit : cost ratio was the highest with 25 kg P205 (3.30) and 20 kg Stha (3.35). Boron application also recorded marked improvement in seed yield (10.6%), uptake of P (8.3%), S (7.30%) and B (1 4.3%), and net returns (1 3.9%) and benefit : cost ratio (4.8%).