Study on the Yield and Yield Contributing Characters of Aus Rice Varieties in Various Soil Moisture Levels

Abstract

The experiment was conducted at the Plant Physiology Laboratory (central laboratory) and Shade house of Field Laboratory of Agricultural Botany Department, Sher-e-Bangla Agricultural University, Dhaka, Bangladesh under a field experiment was also carried out on yield contributing parameters. There were three rice genotypes namely BRRI dhan55 (V 1 ), BR6976-2B-15 (V 2 ) and tolerant check Hashikalmi (V 3 ) and seven water stress were imposed as treatments. The treatments were arranged for 0 days of water stress (control) irrigated continuously throughout the experimental period (T 0 ). When the seedlings were 20 days old, water deficit was imposed for seven days (T 1 ), when the seedlings were 35 days old, water deficit was imposed for seven days (T 2 ), when the seedlings were 55 days old, water deficit was imposed for seven days (T 3 ), when the seedlings were 75 days old, water deficit was imposed for seven days (T 4 ). When the seedlings were 95 days old, water deficit was imposed for seven days (T 5 ) and when the seedlings were 115 days old, water deficit was imposed for seven days (T 6 ). BRRI dhan55 and Hashikalmi produced the highest tillers, grains, number of spikelets and yield. The grain sterility percentage is much higher in BR6976-2B-15 due to water stress treatment compared to other genotypes. Grain yield was the highest in BRRI dhan55 and Hashikalmi and gradually decreased with increased water stress treatment compared to other genotypes. Decreased grain yield per plant under water stress treatment reduction of tillers, panicle, filled grains, root, shoot, spikelet/panicle, panicle dry matter content, and with other causes. The harvest index was decreased due to water stress conditions in all the genotypes while less affected in BRRI dhan55 and Hashikalmi.