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.
