Screening of Bread Wheat Genotypes on Physiological and Agronomical Traits in High Temperature at Different Planting

Abstract

The most crucial factors that reduce developments of plants are the Abiotic stresses. Among abiotic stresses, high temperature is the imperative factor that causes a reduction in crop growth and effect yield. Nowadays, the temperature of Pakistan has raised with approximately <50⁰C, affecting the wheat crop from anthesis stage till maturity and hence, limiting the productivity of wheat. This study focuses on examining the effects of high temperature on wheat genotypes when planted with different sowing date viz. 10^th November and 20^th December of the year 2017-18, using Randomize Complete Bloch Design (RCBD). Product yield from both sowing dates (early and late) were observed with significant difference in all types of genotypes; for days 75% maturity, 1000-grains yield, grain yield (kg/ha^-1), biological yield (kg/ha^-1) and in some physiological characters such as area (cm²) of flag leaf, relative percent of water content ( %) and chlorophyll content % at the probability level P≤0.01 and probability level P≤0.05. The early and late planting revealed significant different recorded in RWC (%) and Leaf Area. The late sowing date, the trait RWC (%) shown non-significant result. The maximum reduction recorded in HYT 10 advance line for grain yield kg/ha^-1, leaf area and RWC and in HYT 09 more reduction of chlorophyll content was observed. Hence, it was due to delayed planting effect and heat stress.