Influence of seeding time and density of plants on growth and productivity of the sunflower

Abstract

With the advent of new sunflower hybrids in manufacturing determining of optimal parameters of major growing agrotechnical practices for them, including plant density at different seeding time has a significant urgency. Analysis of literary sources shows that for this purpose new hybrids listed in the State Register of Plant Varieties of Ukraine in conditions of Right-Bank Forest-Steppe have not been investigated although they differ in the duration of the growing season, morphotype, response to agrotechnical measures and resistance to diseases and drought. Therefore the purpose of our research was studying these issues. The study was carried out during 2012−2014 in the field crop rotation of Department of Crop Production. Two-factor field experiment provided the following: term of sowing depending on the soil temperature at a depth of seeding – respectively 6−8°C (control), 10−12 and 14−16°C and plant density – 40 (control), 60 and 80 thousand of plants/ha. As a result of studies it is found that increasing plant density from 40 to 60 thousand of plants/ha as well as postponement of sowing from the second decade of April to the second decade of May contributes a considerable enhancing of growth processes. To have the highest yield level the early sowing period was the most optimal when at the depth of seeding the soil temperature was 6−8°C which provides obtaining seed yield over 2.0 t/ha.