Effect of spacing of transplanting on the performance of short duration aman rice varieties

An experiment was conducted at the Agronomy Field Laboratory, Bangladesh Agricultural University, Mymensingh from July through October 2015 to evaluate the effect of spacing of transplanting on the performance of four short duration aman rice varieties. The experiment consisted of four rice varieties viz. BRRI dhan56, BRRI dhan57, BRRI dhan62 and Binadhan-7 and three spacings viz. 25 cm × 15 cm, 20 cm × 15 cm, 20 cm × 20 cm. The experiment was laid out in a randomized complete block design with three replications. Growth, yield attributes and yield of transplant aman rice were significantly influenced by variety and spacing of transplanting. Plant height and total tillers hill-1 were significantly affected by rice varieties and spacing of transplanting at 40 and 60 DATs. At 60 DAT, the tallest plant (90.04 cm) and the highest number of tillers hill-1 (11.76) were found in BRRI dhan56. At harvest, the tallest plant was recorded in the variety BRRI dhan56 and the shortest one in BRRI dhan57. The highest number of total tillers hill-1 , effective tillers hill-1 , longest panicle (25.60), highest number of grains panicle-1 , heaviest 1000-grain weight, highest grain, straw and biological yields were found in BRRI dhan56. The highest number of sterile spikelets panicle-1 was found in BRRI dhan57. The plant spacing exerted significant effect on the growth parameters, yield and yield components of rice varieties. At 60 DAT the tallest plant and the highest number of total tillers hill-1 were found in 25 cm × 15 cm spacing. At harvest, the tallest plant, highest number of total tillers hill-1 , effective tillers hill-1 , highest number of grains panicle-1 , highest grain, straw and biological yield were obtained from the spacing of 25 cm × 15 cm. The highest grain yield (5.25 t ha-1 ) was recorded from the cultivar BRRI dhan56 with 25 cm × 15 cm spacing which was statistically similar (5.11 t ha-1 ) with rice cultivar BRRI dhan62 with 25 cm × 15 cm spacing and BRRI dhan56 with 20 cm × 15 cm spacing. From the results of the study, it may be concluded that BRRI dhan56 with 25 cm × 15 cm spacing was the best combination for obtaining highest yield of T. aman rice.

Key words: Growth, Plant spacing, short duration varieties, yield.