EFFECT OF LATE SOWING HEAT STRESS ON GROWTH AND PRODUCTIVITY OF MAIZE VARIETIES

Abstract

An experiment was conducted at the Research field of Crop Physiology and Ecology of Hajee Mohammad Danesh Science and Technology University, Dinajpur during the period from December 2017 to April 2018 to evaluate the growth and productivity of four maize varieties under late sowing heat stress condition. The experiment was laid out in a Split plot design with three replications. The experiment consisted of two factors: Factor A: Two growing conditions (Normal and late sowing heat stress) and Factor B: Four maize varieties (BARI Hybrid Maize-5, BARI Hybrid Maize-7, BARI Hybrid Maize-12 and BARI Hybrid Maize-14). The combined effect of sowing times and maize varieties significantly influenced plant height, leaf length, cob length, cob girth, tassel length, number of grains cob-1 , grains weight cob-1 , 100-grain weight, straw yield and grain yield. Late sowing heat stress caused reduction in all growth and yield contributing traits of maize and the degree of reduction was different to different varieties. In respect to all growth and yield contributing traits, BARI Hybrid Maize-14 showed comparatively better tolerance under late sowing heat stress condition. Both under normal and late sowing heat stress condition, the maximum grain yield (10.55 and 9.32 t ha-1 , respectively) was observed in BARI Hybrid maize-14, whereas BARI Hybrid Maize-12 produced the minimum grain yield (3.38 t ha-1 ) under late sowing heat stress condition. However, the order of heat tolerance based on grain yield was BARI Hybrid Maize-14 > BARI Hybrid Maize-5 > BARI Hybrid Maize-7 > BARI Hybrid Maize-12.