ADAPTIVE ABILITY OF WINTER WHEAT VARIETIES IN THE CONDITIONS OF THE SOUTHERN STEPPE OF UKRAINE

Abstract

Aim – to determine the adaptive characteristics of winter wheat varieties of the selection which was devel-oped in the Irrigated Agriculture NAAS, suitable for cul-tivation in conditions of irrigation and waterless valleys in conditions of the drought South Steppe of Ukraine. Methods – the field, laboratory, genetic-selection , sta-tistical 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 technol-ogies. 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 varie-ties was significantly different – from 0.29 (XH Akvarel) to 0.43 (Kosheva), which indicates the different reac-tion of these varieties to improvement (or deterioration) of growing conditions. To distributе the varieties accord-ing to their suitability for certain growing conditions, the parameters of environmental plasticity (bi) and stabil-ity (S2di) were calculated. The homeostatic varieties havebeen established, which are characterized by a weak response to changes in the growing conditions and they provide stable yields under irrigation conditions and with-out 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 reac-tion to the unstable weather conditions and the agricultural background fluctuation. These varieties have the highest demand in proceedings and can be sown both during irri-gation and without irrigation. The most stable and predict-able increases (decreases) of a yield have the Burgunka, Anatolia, Maria, Rosinka, Khersons awnless, XN Akvarel varieties in the various of agro-ecological gradients.