2000 Ahmed Evaluation of Urea Super Granule as a Source of Nitrogen in Transplant Aman Rice
A field experiment was conducted during the Kharif season (June to November) of 1998 at the Agronomy Field Laboratory, Bangladesh Agricultural University, Mymensingh to study the effect of point placement of urea super granule (USG) and broadcasting prilled urea (PUJ as sources of N in Transplant aman rice. One hybrid variety (Hybrid rice 6201 l and one modern inbred variety (BRRI Dhan 32) were included in the experiment. USG and PU were applied @ 40, 80, 120 or 160 Kg N ha-1. A control (no N) treatment was also included in the experiment. Hybrid rice 6201 produced significantly longer panicle and higher number of total spikelets panicle-1, but showed poor performance regarding all other yield parameters. A considerable difference was noted between these two varieties in respect of spikelet sterility where Hybrid rice 6201 produced almost the double of sterile spikelets than that of BRRI Dhan 32 which ultimately led to inferior grain yield (3.25 t ha-1). On the other hand, BRRI Dhan 32 produced taller plants, higher number of effective tillers hill-1, grains panicle-1 and heavier grains which eventually contributed tb higher grain yield (3.85 t ha–1 ). USG was more efficient than PU at all respective levels of nitrogen in producing all yield components and in turn, grain and straw yields. Placement of USG @ 160 kg N ha-1 produced the highest grain yield (4.32 t ha-1) which was statistically identical to that obtained from 120 kg N ha-1 as USG and significantly superior to that obtained from any other level and source of N.