The Effect of Drought Stress on Grain Yield, Yield Components and Some Quality Traits of Durum Wheat (Triticum turgidum ssp. durum) Cultivars

Abstract

Drought, one of the environmental stresses, is the most significant factor restricting plant production in the majority of agricultural fields of the world. Wheat is generally grown on arid-agricultural fields. Drought often causes serious problems in wheat production areas. A field study was conducted on clay-silt soil, in the Research Field, Southeastern Anatolia Agricultural Research Institute, in Diyarbakır during 1999-2000 growing season in order to evaluate genotypes for yield, yield components and some quality traits. Fourteen wheat (Triticum turgidum ssp. durum) cultivars were grown under well watered and natural drought conditions. Morphological traits were measured at anthesis and yield, yield components and quality traits were evaluated at ripening time. The flowering period was negatively associated with grain yield, while grain filling period, chlorophyll content, number of grains per spike and spikelets per spike were positively associated with grain yield under drought conditions. Moreover, the number of days to maturity was negatively associated with Drought Susceptibility Index (DSI), while Spike length was positively associated to DSI in drought conditions. DSI and relative yield (RY) values for grain yield were used to describe yield stability and yield potential. There were high variations in DSI and RY values within genotypes. DSI values for grain yield ranged from 0.82 to 1.07 and the mean RY values were 0.82 for well-watered plots and 0.87 for water stressed plots. The varieties ‘Gidara-II’, ‘Sarıçanak-98’, ‘Balcalı-2000’, ‘Altıntoprak-98’, ‘Aydın-93’ and ‘Harran-95’ showed high yield potential and stability (DSI<1 and RY>mean RY).