Ecological adaptability of sunflower hybrids to different soils and climatic conditions depending on some elements of agricultural technology

Ecological tests of sunflower hybrids of different maturity groups of «Limagrain» breeding - LG 5400 HO, Goldsun, LG 5580, LG 5662 were carried out in farms of Volgograd, Saratov, Rostov and Krasnodar regions in 2013. The test results showed that the highest average yield was observed on middle early sunflower hybrids Goldsun (3.10 t/ha) and LG 5580 (3.07 t/ha). It was found that under adverse weather conditions it is advisable to cultivate hybrid LG 5580, and if it’s possible to provide in these conditions good agricultural techniques - Goldsun is the best. Early hybrid LG 5400 HO has almost full compliance of changes in yields with changes in environmental conditions, so it is preferable to use it in favorable conditions but it can form a high yield in stressful conditions due to the short growing season, by which a hybrid can avoid critical period and maximum impact of negative environmental factors (high average daily temperature, soil and air drought). Hybrid LG 5662 is characterized by an average level of yield, it’s poorly responsive to changes of environmental conditions and, therefore, it can be cultivated on extensive technology, where it will provide a good level of yield with minimal efforts. Investigations of the influence of plant population density and seedbed dressing (N 30P 30K 30) on yield and oil content in seed of sunflower hybrids of the different maturity groups were carried out on the leached black soil in Kursk and Krasnodar regions. It was found that the usage of seedbed dressing is helpful in Krasnodar region (yield increase was 0,16 t/ha, oil content increase was 0,9 %) and in the Kursk region this element of agrotechnology doesn’t cause a positive reaction of represented genotypes, except of hybrid of an early maturity group LG 5400 HO with seed sowing rates of 60 and 80 ths/ha (yield increase of 0,39 and 0,24 t/ha, oil content increase of 1,8 and 2,3 % respectively). The optimum seed sowing rate has been found for the studied hybrids (60-80 ths/ha), where the maximum realization of their potential is obtained in the soil and climatic conditions of Krasnodar and Kursk regions.