Effect of irrigation on Indian mustard (Brassica juncea) sown on conserved moisture

A field experiment was conducted during the winter (rabi) season of 1995–96 and 1996–97 on loamy sand soil of Regional Research Station, Bawal, to study the response of Indian mustard [Brassica juncea (L.) Czernj & Cosson] to irrigation scheduling. In Indian mustard sown on conserved moisture, application of 2 irrigations, one essentially at initiation of branching (40 days after sowing) and the other either at flowering (60 days after sowing) or pod-development stage (100 days after sowing) resulted in statistically equal yields to 3 irrigations. Water stress during initiation of branching through pod-development stage caused 28% reduction in yield, while stress throughout crop season reduced yield by 35% as compared to no-water stress. The mean net returns were maximum (Rs 14,986/ha) when 2 irrigations were applied at initiation of branching and flowering stages. The benefit: cost ratio in this treatment (2.56) was statistically at par with the maximum value of 2.59 obtained with irrigation applied at initiation of branching. The increasing number of irrigations increased the consumptive use of water but decreased the water-use efficiency.