Effect of drought on yield and yield components of durum wheat and triticale in a Mediterranean environment

Abstract

Field experiments were carried out with durum wheat and triticale under different moisture levels, in a typical Mediterranean climate. Yield of wheat showed significant reductions (by 25, 54 and 87%) under drought stress, while triticale showed only a slight and non-significant decrease (by 8%) in comparison to the irrigated control. The most severe stress (treatment S) caused a reduction in all the yield components of wheat, but particularly in the number of fertile ears per unit area (by 60%) and in the number of grains per ear (by 48%). In contrast, the reduction in yield under the mild stress was solely due to a lower grain weight. Harvest index and nitrogen harvest index were significantly decreased (going from 48 to 24% and from 64 to 42% respectively) in cases of severe drought in wheat. Male sporogenesis was only studied in the case of mild drought, which was not severe enough to delay it or to induce male sterility, and only caused sporogenesis to begin earlier. The greater drought resistance of triticale can be attributed to the earliness of its heading date and to the greater capacity of its roots to extract water from the soil.