Е. К. Барнашова The aim of the work was to study the effect of precipitation and temperature during the vegetative season on the oil content of the studied sunflower cultivars. The article examines the dynamics of changes in the oil content of the sunflower cultivars selected by the Federal State Budgetary Scientific Institution “Federal Center of Agriculture Research of the South-East Region” for 2010–2019. It was revealed that the most favorable conditions for oil accumulation were observed in 2013, 2017 and 2019. The cultivar Stepnoy 82 showed the most constant high oil content (49.45%) compared to other cultivars during the 9-year research period. The method of two-factor analysis of variance determined the share of the effect on the oil content of cultivar factors (A) – 14.7%, year conditions (B) – 66.59% and their interaction (AB) – 12.9%. An average correlation between the amount of precipitation and the oil content in the germination-budding period (June – first half of July) was observed in the cultivars Stepnoy 81, Stepnoy 82, Saratovsky 86 and Saratovsky 82. During flowering (second half of July) there was an average correlation (r = 0.31–0.65) between these indicators in most of the cultivars studied; during seed filling (August) there was a weak negative correlation in all cultivars. During the period of physiological seed maturity (September), the cultivars Saratovsky 21, Stepnoy 82, Saratovsky 85 and Saratovsky 86 showed an average correlation between the amount of precipitation and the oil content. There was a negative correlation between the temperature regime and the oil content of the seeds of the cultivars studied throughout the vegetative season. The greatest contribution of precipitation to the oil formation process was observed in July in the cultivars Skorospely 87 (41%) and Saratovsky 20 (42%), and the greatest contribution of temperature was observed in July and August in the cultivar Slastena (71 and 48% respectively). There was a slight variation in the oil content between cultivars over the years, ranging from 4.7% in Skorospely 87 to 6.55% in Slastena.
Научная статья 
вегетационный период