Aim – to determine the adaptive characteristics of winter wheat varieties of the selection which was developed in the Irrigated Agriculture NAAS, suitable for cultivation in conditions of irrigation and waterless valleys in conditions of the drought South Steppe of Ukraine. Methods – the field, laboratory, genetic-selection, statistical and retrospective methods were used. Оver the 130-years period the retrospective yield analysis of the main grain crops in the arid Steppe zone showed that the annual yield increase of the main grain crops ranged from 5 kg/ha to 21 kg/ha. The most noticeable increase in yield was recorded in the winter wheat – it has gone up 5.65 times, and increased from 6.00 to 33.9 centner/ha, and on the irrigated lands – to 52.1 centner/ha, which exceeds the figures of the nineteenth century beforе by a factor of 8,7 times. The annual yield increase amounted to 0.34 centner/ha as a result of the usage of the new varieties and the improvement of the cultivation technologies. The new wheat varieties Kohana, Kosheva, Maria, Soborna, XN Akvarel have a high yield potential under the irrigation conditions of 9.25–10.35 t/ha. However, fluctuations in the grain yield without irrigation are quite high. The drought hardness coefficient of these varieties was significantly different – from 0.29 (XH Akvarel) to 0.43 (Kosheva), which indicates the different reaction of these varieties to improvement (or deterioration) of growing conditions. To distributе the varieties according to their suitability for certain growing conditions, the parameters of environmental plasticity (bi) and stability (S2 di) were calculated. The homeostatic varieties have been established, which are characterized by a weak response to changes in the growing conditions and they provide stable yields under irrigation conditions and without irrigation. This group includes the Anatolia, Ledya, Rosinka, Burgunka varieties. The varieties Konka, Maria, Sobornaya, XN Akvarel are classified as an intensive type with a high genetic potential but with a low stability of yield manifestation. These varieties have a very high potential yield (over 10 t/ha), but they require careful and timely implementation of the technological operations under the irrigation conditions. The varieties Kohana, Kosheva, Kherson 99, Ovidii have a suitable reaction rate for improving the growing conditions, and a restrained reaction to the unstable weather conditions and the agricultural background fluctuation. These varieties have the highest demand in proceedings and can be sown both during irrigation and without irrigation. The most stable and predictable increases (decreases) of a yield have the Burgunka, Anatolia, Maria, Rosinka, Khersons awnless, XN Akvarel varieties in the various of agro-ecological gradients
wheat, irrigation, selection, yield, drought resistance, plasticity