Wheat Information Service
Number 70: 1 - 3 (1990)

A note on drought resistance in wheat

R. K. Chowdhury

Department of Plant Breeding, Haryana Agricultural University, Hisar-125004, India

Breeding major food crops for stable yields under drought/rainfed stress environments has become a subject of major interest (Fischer et al 1982). Various mechanisms imparting drought resistance like : escape, endurance avoidance and tolerance etc. have been put forward by various workers. However, still plant breeders are largely guided by the grain yield response in selecting for drought resistance due to lack of well defined informations on the above mechanisms. The black box approach i.e. testing of performance of genotypes under stress situation is a very useful step in breeding programmes mainly because it allows a direct estimate of drought resistance or susceptibility of individual genotypes.

Though stricking increases have been achieved in the wheat yields all over the world with the development of modern high yielding and high input responsive varieties after the introduction of dwarfing genes (Norin 10), however, yields under drought/rainfed conditions are still low/stagnant. The rainfed wheats accounts for about 35 per cent of the total acreage of wheat in India, therefore, it would be desirable to screen the genotypes under rainfed conditions so that the best/better genotypes could be identified and utilized in future breeding programes.

Having this in mind, a total of 115 genotypes of wheat including T. aestivum and T. durum mostly taken from "National Drought Screening Nursery" were screened for their yield performance at Haryana Agricultural University, Regional Research Station, Bawal for three years; 1979 - 80, 1980 - 81 and 1981 - 82 to identify varieties best suited under drought/rainfed conditions. Bawal is situated in South-Western part of Haryana State. The climate in this zone is semi-arid with very erratic rainfall. The soil is loamy sand, weakly alkaline (pH 7.8), bulk density 1.45g cm³ having 84.6 per cent sand, 6.7 per cent silt and 8.7 per cent clay. The data were recorded on grain yield/m row length (g) and total dry matter produced i.e. biological yield/m row length (g). The harvest index (%) was calculated by dividing grain yield with total biological yield.