Selection of spring soft wheat (Triticum aestivum L.) varieties for the adaptability in the conditions of steppe zone of the Akmolinsk region, Kazakhstan

The spring soft wheat (Triticum aestivum L.) planting acreage makes 78 % of the crops of cereals grown in Akmolinsk region, the North Kazakhstan. The wheat productivity can reach 1.4-1.8 t/ha which makes it possible to harvest high yield with high grain quality and high protein level. That is important when cultivating strong wheats, the so called improvers. At the present time, searching for the reserves to increase yield and to improve grain quality in wheats is of interest. Here, the key role is given to a variety because over 20 % of an increase in the crop yield is due to varietal features. This article presents data on phenology, nodal root formation, the main yield elements, and the total yield of spring wheat (Triticum aestivum L.) promising varieties Karagandinskaya 22, Karagandinskaya 29, Karagandinskaya 70, Seke, Sary-Arka, and Stepnaya 60. The estimations have been carried out according to the Kazakhstan State Crop Variety Testing protocol. Field trials were carried out in 2011-2013 using fallow land as a predecessor in the test field of Ualikhanov Kokshetau state University (Kokshetau, Kzakhstan). The conditions of the steppe zone were favorable for nodal root development which number per plant reached 5.5 for Karagandinskaya 22, 4.5 for Stepnaya 60, and 5.2 for Seke. The number of nodal roots during plant growth increased from tillering to full grain ripeness. In the arid conditions of the steppe zone the length of growing season is of importance. Among the varieties, the vegetation period was optimal in Karaganda 22 (94 days), with an average 96 day period for all the varieties studied. The main components of wheat yield were shown to be beneficially influenced by the climate conditions. The plant number per 1 m2 at harvesting was 230-282, the productive tiller number per 1 m2 was 201-333, the seed number per ear was 20-30, and the 1000 seed weight was 36.4-49.6. Grain productivity of the varieties Karagandinskaya 22, Sary-Arka, and Stepnaya 60 was 4.0, 3.6, and 3.4 t/ha, respectively. So their yielding was higher compared to only 1.8 t/ha for the standard variety Svetlanka. During selection for adaptability in the conditions of steppe zone of the region, the main emphasis should be given to the number of kernels per ear (r = 0.86±0.13) and the 1000 grain weight (r = 0.76±0.12). In a model variety for the steppe zone of the region, the main yielding parameters must be as follows: 96 day-length of vegetation, 25 to 30 seeds per ear, productive tillering of 1.1 to 1.2, and the yield of 3.0-4.0 t/ha. The 1000 seed weight should be 33-36 g for the fraction of mid-size seeds, and more than 38-45 g for larger seeds.