EFFECT OF TRANSPLANTING DATE ON THE GROWTH AND YIELD OF AMAN RICE IN POLDER ECOSYSTEM OF THE SOUTH-WESTERN COASTAL ZONE OF BANGLADESH

Abstract

A field experiment was conducted on the farmers’ fields in polder 30, Batiaghata, Khulna during July 2017 to January 2018 in order to study the influence of different transplanting dates on the performances of aman rice under tidal ecosystem prevailing in the polders of the south-western coastal zone of Bangladesh. The experiment consisted of two level of treatments viz. variety and transplanting dates. The experiment was comprised with two rice varieties viz. BRRI dhan52 and Kumragor (local T. aman rice) and seven transplanting dates viz. 1 July, 10 July, 20 July, 30 July, 10 August, 20 August, 30 August. The experiment was laid out in Randomized Complete Block Design (RCBD) with five dispersed replications. Results indicate that variety and date of transplanting exerted significant influence on the crop characters of aman rice. BRRI dhan52 produced the highest grain yield (3.51 t ha ), straw yield (3.72 t ha -1 ), biological yield (7.24 t ha ii -1 ), and harvest index (48.30%). The lowest grain yield (2.71 t ha -1 ), straw yield (4.40 t ha -1 ) and biological yield (6.57 t ha -1 ) and harvest index (32.88%) were obtained from Kumragor. Kumragor took longest duration 152 days to mature while BRRI dhan52 took 133 days to mature. Plant height (140.12 cm), number of total tillers m- 2 (240), number of grains panicle -1 (132.19), grain yield (3.63 t ha -1 ), straw yield (4.60 t ha -1 ), biological yield (8.27 t ha -1 ) and harvest index (44.01%) were highest with 10 August transplanting and decreased gradually after mid-August transplanting but drastically declined with 30 August transplanting. Drastic decrease of yield was showed on both of the transplanting date 1 July and 30 August. The present study indicates early August to be the most suitable transplanting date for aman rice in polder ecosystem of coastal zone.