The effect of irrigation water on the yield and on individual yield components was examined for 19 durum wheat varieties by continually recording weather data and carrying out measurements on the moisture content, temperature, electrical conductivity and tension of the soil. Dry (rain-fed) and irrigated treatments were included in the experiment, which was carried out in the framework of the EU FP7-244374 DROPS project.During the rainless spring of 2011 the soil moisture content of the non-irrigated area dropped to 21–22 vol% and the effect of drought stress was still felt at harvest. The quantity of irrigation water applied during the growing season ensured normal conditions for generative development and a significant difference could be detected between the yield components in the two treatments. The thousand-kernel weight of the varieties was identical in the dry and irrigated plots, but in response to irrigation there was an increase in the number of grains per ear and the grain weight, and an improvement in fertilisation, resulting in higher yields.