EFFECT OF NITROGEN SOURCES ON SPIKELET STERILITY AND YIELD OF BORO RICE

Abstract

A research work was carried out at the Agronomy Farm, Sher-e-Bangla Agricultural University, and Dhaka during the period from November 2012 to June 2013 in order to determine the suitable nitrogen source to observe the growth performance with a view to increasing the grain yield by reducing spikelet sterility in boro rice. The experiment comprised four sources of nitrogen viz. no nitrogen, BRRI recommended dose of prilled Urea, Govt. approved dose of mixed NPK and BARC recommended dose of urea super granule (USG), and four varieties viz. BRRI dhan29, BRRI dhan58, BADC SL8H and Heera. The experiment was set up in a split-plot design with three replications. Experimental results indicated that nitrogen sources had significant effect on plant height, tillers hill -1 ,

effective tillers hill -1 , non-effective tillers hill -1 , grains panicle , unfilled grains panicle -1 , spikelet sterility (%), grain yield, straw yield, biological yield and harvest index. The application of USG showed the highest grain yield (8.64 t ha -1 ) and the lowest spikelet sterility (%) than any of nitrogen and other sources of nitrogen treatments. All the studied characters except harvest index varied significantly due to varieties. Among the varieties, BRRI dhan29 out

-1 yielded Heera, BADC SL8H and BRRI dhan58 by 0.85, 1.13 and 1.98 t ha , respectively which is mainly attributable to the highest number of grains panicle 1 (98.57) and markedly lower level of spikelet sterility (11.13 %). The combination of the USG application and BRRI dhan29 had the higher performance in terms of producing the highest grain yield by significant reduction of spikelet sterility (%) among the interaction effects. -1 -