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Abstract

The article analyzes the results of two years field trials carried out in 2016- 2017 in the dry steppe zone of Northern Kazakhstan, with the aim of determining the influence of weather conditions on yield 16 different types at the time of maturity (early, medium early and mid-season) hybrids of sunflower. In studies it was found that for the formation of high-yield seeds, in addition to an optimal
temperature, a very important number and distribution of precipitation caused by pre-sowing period and the vegetation period. Sunflower makes good use of soil moisture reserves, which are created by autumn-winter rainfall. The conditions of moisture, the seed layer at the time of seeding were satisfactory for future seed germination and the emergence of amicable shoots (stocks of productive moisture from 11,6 to 13,8 mm). Germination of plants averaged over the two years of 77– 87 %, and good rooting of plants in the early growing season allowed us to get to cleaning good plant survival in the range of 90,3–94,6 %. The magnitude of these figures it can be noted that all hybrids are well adapted to the conditions in the area. Years of research significantly differed on weather conditions at different levels of water supply plants, the yield of sunflower hybrids was significantly different: in the wet 2016 year with the abundant rains in june–july months (on 113% higher than the average annual norm) it ranged from 28,5 to 41,2 с/ha; in the absence of precipitation during the critical phase of plant development in 2017 year (rigid drought in the second half of the growing season) is from 6,5 to 9,0 с/ha. Comparative evaluation of sunflower hybrids for productivity on the background of the influence of agroclimatic resources of the dry steppe zone showed, that on dark-chestnut soils are promising for cultivation are: from early maturing group hybrid – Rocky and Tristan, from the middle-early group – Sanay, Delfi, Cadix, from the group of medium ripening – Diamantis, Bacardi, Neostar.