Effect of Transplanting Dates, Cultivars and Irrigation Regimes on Microclimate and Yield of Rice

Abstract

A field experiment was conducted at BCKV, Kalyani, West Bengal (Latitude 22°59’13’’ N, Longitude 88°27’20’’ E) to evaluate the performance of different rice cultivars grown during kharif season of 2017. The experiment was laid down in a split split-plot design where four dates of transplanting (16^th June, 30^th June, 14^th July and 28^th July) were allotted in main plot, three rice cultivars (Nayanmani, Satabdi, Swarna) in sub-plot and two irrigation regimes (Optimum and Deficit) in sub-sub plot. Result revealed that the grain yield (4365 kg ha^-1) was recorded in 16th June transplanting, highest which significantly declined by 15%, 31% and 36% respectively with delay in transplanting. Deficit irrigation resulted 851 kg ha^-1 less grain yield compare to optimum irrigation condition (3915 kg ha^-1). Grain yield under different variety was in the order of Nayanmani (4495 kg ha^-1) > Swarna (3008 kg ha^-1)>Satabdi (2965 kg ha^-1).The highest magnitude (0.98 g MJ^-1) of radiation use efficiency was noted under D₁, which decrease gradually with delay in transplanting time (0.79 g MJ^-1>0.64 g MJ^-1>0.58 g MJ^-1). The highest magnitude (0.87 g MJ^-1) of RUE was noted under optimum irrigation_, which was 0.15 g MJ^-1 less under deficit irrigation. Among the varieties, the highest magnitude (1.10 g MJ^-1) of RUE was recorded under Nayanmani, which was 0.40 g MJ^-1 less under Satabdi. The lowest RUE (0.48 g MJ^-1) was noted under Swarna.