RELATIONSHIP BETWEEN AGRO-METEOROLOGICAL INDICES AND YIELD OF RICE AT VARYING TRANSPLANTING DATES IN BORO SEASON

Abstract

Executive Summary The experiment was conducted at the Research Farm of Sher-e-Bangla Agricultural University, Dhaka-1207, Bangladesh, during December, 2022 to May, 2023 to evaluate the effect of variety and their transplanting dates on the growth, pheno-phases, yield attributes, yield and the agro-climatic indices of modern rice varieties. Three rice varieties; (BRRIdhan89, BRRIdhan96 and BRRIdhan100) and three transplanting dates (05 January, 25 th January, and 15 th February) were used in this study. The experiment was laid in splitplot

design with three replications. Variety and different transplanting dates exhibited significant variation in crop phenology, yield, yield attributes, and agro-climatic indices. Variety BRRIdhan100 attained early booting, panicle initiation, heading and flowering followed by BRRIdhan96 and BRRIdhan89, respectively. The highest panicles m (243.5), grains panicle -1 (203.64) and grain yield (9.75 t ha -1 ) were obtained from BRRIdhan89. Early transplanting (05 th January) brought the phenological stages late as compared to mid (25

January) and late (15 th February) transplanting. Accumulated growing degree days (AGDD), Helio-thermal units (HTU) and Heat use efficiency (HUE) were significantly higher in BRRIdhan89 being 2069.5 and 4.75, respectively, whereas BRRIdhan100 showed the highest Pheno-thermal index PTI (15.92), irrespective of transplanting dates. Early transplanting exhibited the highest AGDD (2252.77), PTI (16.36) and HUE (4.25). Early transplanting of BRRIdhan89 gave the highest AGDD (2411.71) and HUE (5.23) while the highest PTI (16.53) was recorded in early transplanting of BRRIdhan100.