Sunflower (Helianthus annuus L.) productivity under the effect of akm plant growth regulator in the conditions of the southern steppe of Ukraine

Abstract

Aim. The goal of this research was to determine the infl uence of AKM plant growth regulator on the perfor- mance of large-seed Lakomka sunfl ower variety, sowing and yielding properties of seeds. Methods. Agro- chemical and biometric methods. Mathematical analysis of the results was carried out by Student’s test and licensed Agrostat computer program. Results. The results of the study on the impact of AKM plant growth regulator (PGR) on growth, development and yield formation of sunfl ower in low moisture conditions of Southern Steppe of Ukraine are presented. Pre-sowing seed treatment of Lakomka sunfl ower variety with AKM plant growth regulator causes an increase in leaf surface area by 22 %; pollen fertility – by 27 %; reduces the phenological phases by 2−4 days on average, increases the resistance of sunfl ower plants to abiotic stress and increases yield by 26 %. It is proven that the proportion of the impact of water stress of the studied year (58.4 %) is signifi cantly higher than that of the impact of PGR (32.7 %). Conclusions. AKM plant growth regulator is recommended for the use on sunfl ower in 0.015 g/l concentration.