Effects of age of seedling and nitrogen rates in the nursery bed on growth, yield and yield components of BRII dhan52 under submerged condition

Abstract

The experiment was conducted at the Agronomy Field Laboratory, Bangladesh Agricultural University, Mymensingh during July to December 2013 in the aman season to investigate the effect of age of seedling and nitrogen rates in the nursery bed on growth, yield and yield components of BRRI dhan52. The experiment comprised of three ages of seedlings viz., 30, 35 and 40 day old and four nitrogen rate N₁-N@50 kg ha^-1, N₂-N@75 kg ha^-1, N₃-N@100 kg ha^-1, N₄-N@125 kg ha^-1. The experiment was laid out in a split plot design with three replications. Age of seedling showed significant differences for shoot weight, survivor, no. grains panicle^-1, panicle length, grain yield and straw yield. The highest root weight (0.072 gm^-2), plant height (108 cm), total tillers hill^-1 (8.22), effective tillers hill^-1 (7.03), non-effective tillers hill^-1 (1.19), survivor (95.1%), grains panicle-1 (106.2), grain yield (5.57 t ha^-1), straw yield (6.26 t ha^-1) and harvest index (0.47%) were found by transplanting 40 day old seedlings. The highest shoot weight (0.53 gm^-2), 1000 grain wt. (25.3g) was found by transplanting 35 day old seedlings and 30 day old seedlings produced highest sterile spikelets (28.9) and panicle length (23.8 cm). Nitrogen rate in the nursery showed significant differences for shoot weight, root weight, survivor, plant height, total tillers hill^-1, effective tillers hill^-1, non-effective tillers hill^-1, panicle length, grains panicle^-1, grain yield and straw yield. Application of 50 kg N ha^-1 gave higher plant height (108 cm) and harvest index (0.47%). On the other hand, application of 75 kg N ha^-1 produced highest noneffective tillers hill^-1 (1.0), grains panicle^-1 (100.7), 1000 grain weight (25.3 g) and harvest index (0.47%). Application of 100 kg N ha^-1 gave highest total tillers hill^-1 (7.85), effective tillers hill^-1 (6.85), noneffective tillers hill^-1 (1.0), survivor (90.5%) and grain yield (5.01 t ha^-1). Application of 125 kg N ha^-1 gave highest panicle length (23.75 cm), grains panicle^-1 (100.7), noneffective tillers hill^-1 (1.0) and sterile spikelets (30.1). Forty day old seedlings grown with 100 kg N ha^-1 at nursery found to be better in respect of grain yield. The result of the experiment also showed that aged seedlings regenerated quickly after desubmerge of water.

Res. Agric., Livest. Fish.2(2): 261-269, August 2015