Effects of deficit irrigation on grain yield and some morphological traits of wheat cultivars in drought - prone conditions

This study was conducted to determine the influence of deficit irrigation on grain yield and some morphological traits of wheat cultivars. The experiment was a split plot randomized complete block design in four replications over two successive cropping seasons (2006-2008) at the Agricultural Research Station in Zahak, Iran. In the main plots were the different levels of deficit irrigation: T1= irrigation at all stages (full irrigation), T2= no irrigation before stem elongation, T3= no irrigation before flowering and T4= no irrigation before grain filling. Sampled in the sub plots were the four wheat cultivars: Hamoon, Kavir, Dez and Peethee nr2. The results of combined analysis of variance showed that the effect of irrigation in both seasons was significant on grain yield and morphological traits. The highest grain yield resulted from irrigation at all stages with a yield of 6275 kg/ha. Deficit irrigation was found to decrease grain yield by 5% at no irrigation before stem elongation, by 32% at no irrigation before flowering and by 52% at no irrigation before grain filling. Deficit irrigation affected the characteristics of; spikes/m 2 , biomass and harvest index. Grain yields were significantly different between the cultivars: Hamoon and Kavir cultivars produced the highest (5540kg/ha) and the least (4326kg/ha) grain yields, respectively. Hamoon had a higher drought tolerance therefore greater grain yield than the other cultivars in conditions of a drought-prone environment.