Sunflower yield depending on weather conditions and hybrid composition

Abstract

Purpose. Investigate new sunflower hybrids to assess yield in Poltava region.Methods. Field, laboratory and statistical.Results. The article presents the results of studies on the influence of the weather of the growing season on the formation of yield of district sunflower hybrids in the conditions of the Left Bank forest-steppe. Hybrids were evaluated on the experimental field of Poltava State Agricultural Experimental Station named after M. I. Vavilov, Institute of Pig Production and Agro-Industrial Production of the National Academy of Sciences of Ukraine during 2014–2018 years. The subject of research – hybrids of sunflower of domestic and foreign breeding. The relationship between yields and weather conditions was performed by multivariate regression using time series with the exception of non-yielding members; between rainfall during the growing season and yield – a method of parabolic dependence approximation. According to the results of the calculations, it was found that the amount of rainfall in June and July and the sum of active temperatures in May and July have a great influence on the level of harvest under conditions of unstable and insufficient humidity. The weather conditions during the years of the researches differed in terms of thermal regime and humidity level. So the most optimal conditions were in 2015 year and the highest yield was obtained on all hybrids – 3,86–4,02 t/ha, the worst in 2017 year – 2,84–2,87 t/ha, according to the ripeness group. Analyzing the rainfall during each growing season and the yield of sunflower hybrids by the parabolic dependence method, it was noted that the 70 % yield (R2 = 0,7) depends on the rainfall in June, which makes it possible to predict the future harvest. It was found that in the conditions of insufficient and unstable moistening the highest average yield, at the level of 3,44 t/ha, during the years of research was formed by hybrids of the middle-aged group. Thus, in the conditions of the Left Bank forest-steppe, to obtain stable sunflower crops, preference should be given to hybrids of the middle-aged group.