Effects of date of sowing on the yield and yield components of spring wheat and their relationship with solar radiation and temperature at Ludhiana, Punjab, India

Abstract

This Wheat Special Report analyzes the effects of radiation and temperature on the date of flowering and grain yield of spring bread wheat cropped under optimum conditions. The experiments were conducted at Ludhiana, Punjab, India, over 7 years and using a range of genotypes. The optimum flowering date for maximization of wheat grain yields is confirmed to be when the ratio of radiation to temperature (PTQ) is at its maximum. The individual effects of radiation and temperature on yield and yield components at various stages of crop development are also examined. We hope that the concepts validated here will be useful elements of wheat component agronomy in the development of new spring wheat varieties and better agronomic practices for wheat grown under irrigation (Mega-environment 1). This long version (No. 23b) has four additional appendices that contains raw data collected during the experiments, which may be of interest to some reseachers. S.S. Dhillon is an agronomist with the Department of Plant Breeding, Punjab Agricultural University, Ludhiana, India, and J.1. Ortiz-Monasterio R. is an agronomist, with the Wheat Program, Crop Management and Physiology Subprogram, CIMMYT, Mexico