The effect of drought on the water use and yield of two spring wheat genotypes

Abstract

SUMMARYAutomatic plot covers were used in a study of the effects of drought on the yield and water use of two spring wheat genotypes. The experiment tested the effects of drought at different stages of growth on yield and yield components. There was complete control over the water supplied to the plots, and a fully irrigated control treatment was included.The yields of the two genotypes were similar under fully irrigated conditions, but the yield components differed: Highbury had more grains per ear and TW 269/9/3/4 more ears per unit ground area and a higher mean grain mass. An early drought, which began 4 weeks before anthesis, caused a reduction in number of grains per ear in Highbury, which was outyielded by TW 269. Late drought also reduced yields differentially, reducing mean grain mass, and hence grain yield, more in TW 269 than in Highbury. Total shoot dry matter and grain yield were found generally to increase as water use increased. The average water use efficiency was found to depend upon the genotype and treatment.