Physiological Growth - Yield Relationships in Wheat Genotypes Under Sowing Date Mediated Heat Stress

By : Radhika, SK Thind, NS Bains, P Chhunneja

Page No: 73-79

Abstract
Twenty five wheat genotypes were classified into two groups i.e. early and late maturing on the basis of their ear emergence and maturity under sowing date mediated heat stress conditions. The early maturing group genotypes were found superior for early emergence and it had spent maximum period of total life span to grainfilling under late sown conditions, but was found poorer in yield than other genotypes of late maturing group. The correlation of grain yield with days to ear emergence and maturity shifted from negative in late maturing group (LMG) to positive in early maturing group (EMG) under both timely and late sown conditions. All plant growth parameters (RGR, LAI, NAR) were adversely affected by temperature stress which finally reflected in yield reduction. The impact of this adversity could be clearly seen to a large extent in late maturing genotypes, However there was clear cut variation among the genotypes for late planting conditions. The measurement of growth parameters LAI, RGR and NAR is important because they are positively correlated to biomass production. Final yield had strong positive association with the NAR and LAI. Their significance becomes crucial particularly under stress environment.

Authors :
Radhika and SK Thind : Department of Botany, College of Basic Sciences and Humanities, Punjab Agricultural University, Ludhiana, India
NS Bains : Department of Plant Breeding and Genetics, Punjab Agricultural University, Ludhiana, India.
P Chhunneja : School of Agricultural Biotechnology, Punjab Agricultural University, Ludhiana, India.