The effect of sowing date on productivity of soybean varieties developed by the ARC “Donskoy" in the south of the Rostov region

Abstract

Soybean is the most important food protein and oil grain crop in the world. However, in the Rostov region, the areas under this crop are insignificant (12.3 thousand hectares or 0.21% of the arable land in 2015). As the Rostov region is the zone of insufficient and unstable moistening, soybean is a promising leguminous crop, which is resistant to lodging and to damage by diseases. The studies were conducted in 2016-2017 to determine soybean response to different sowing time. The research work was carried out on the fields of the FSBSI “Agricultural Scientific Center “Donskoy” (the laboratory of cultivation technologies of row crops) located in the southern soil-climatic zone of the Rostov region. The soil of the test plot is ordinary blackearth (chernozem), heavy loamy, carbonate on forestry loam, with such agrochemical indicators of soil as 3.36% of humus; 7.0 of pH; 24.4 of P2O5; 360 mg of K2O per kg of soil. The object of research was the soybean varieties “Don 21” and “Diva” approved for use in the Rostov region. The article presents the results on the effect of sowing dates on the length of the vegetation period, the elements of yield structure and productivity of soybean seeds. The length of the vegetation period varied depending on the sowing time and was the shortest in the fourth term of sowing, viz. 110 and 116 days for the varieties “Don 21” and “Diva” respectively. The highest values of the elements of the yield structure (the number of beans per plant (21.7 and 19.5 pcs.), seeds' weight per plant (3.87 and 3.58 g) and 1000-seeds weight (146.9 and 146.7 g) were identified in the variety “Diva” (the third sowing term) and in the variety “Don 21” (the second sowing term). In the same variants of the trial, the maximum yields were produced by the varieties “Diva” and “Don 21” (1.38 and 1.25 t/ha respectively).