Evaluating the potentials of boro and aus rice varieties as a substitute to the short duration rice varieties in aman season

Timely sowing/planting of rabi crops in T. aman rice – Rabi crop – Boro rice pattern is very important. Short duration rice varieties are cultivated in aman season to facilitate timely sowing of rabi crops. Most of the short duration aman rice varieties are sensitive to early transplanting and thus, early vacating of land for subsequent rabi crops planting does not happen. This experiment was conducted at the Agronomy Field Laboratory of Bangladesh Agricultural University to investigate the yield performance of some boro rice varieties in response to date of transplanting in aman season. Five rice varieties viz. BRRI dhan28, BRRI dhan48, BRRI dhan55, BRRI dhan58 and Binadhan-7 were transplanted at four dates viz. 21 June, 11 July, 1 August and 22 August 2016 in a split-plot design with three replications. The variety and date of transplanting had significant interaction effects on grain yield and most of the crop characters of rice. BRRI dhan58 produced the highest grain yield (5.45 t ha-1), straw yield (6.17 t ha-1), biological yield (11.62 t ha-1) with in the lowest field duration (96 days) among the different varieties transplanted at different dates. Short duration aman rice variety Binadhan-7 gave the highest yield of 5.10 t ha-1 when planted on 1 August and required field duration of 109 days while BRRI dhan48 gave the highest yield of 5.10 t ha-1 and required 107 days when transplanted on 22 August. The present study concludes that BRRI dhan58 could be used as a short duration rice variety for obtaining high yield in early aman season and for vacating the land for facilitating early sowing of rabi crops.