EFFECT OF TERMINAL DROUGHT ON THE PERFORMANCE OF TRANSPLANTED AMAN RICE

Abstract

An experiment was carried out to evaluate the effect of terminal drought on performance of T. aman varieties at the Crop Physiology and Ecology Research Field, Hajee Mohammad Danesh Science and Technology University (HSTU), Dinajpur during the period from July to November 2018. The experiment was laid out in a split plot design with three replications. The experiment comprised of two sets of treatments such as: Main plot treatment: Two water regimes (Rainfed condition and terminal drought condition) and Sub-plot treatment: Four rice varieties (BRRI dhan71, BRRI dhan62, BRRI dhan56 and BRRI dhan72). Half of the experimental plots were exposed under rainfed condition i.e. it is completely depended on rain water and the remaining plots were protected from rain by rainout shelter after anthesis to expose terminal drought stress. Data were collected on plant height, number of leaves per hill, number of tillers per hill, SPAD value, leaf area, leaf dry weight, number of filled and unfilled grains per panicle, panicle length, 1000-grain weight, grain and biological yields. All the growth and yield contributing characters and yield of all T. aman rice were reduced due to terminal drought over rainfed condition. Among the varieties yield contributing characters and yield of BRRI dhan71 and BRRI dhan62 affected least but yield characteristics and grain yield of BRRI dhan56 and BRRI dhan72 were reduced drastically under terminal drought over rainfed condition. Based on susceptibility tolerance index the order of tolerance of four T. aman varieties is BRRI dhan71> BRRI dhan62 >BRRI dhan56 > BRRI dhan72.