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.
