GRAIN YIELD OF SOYBEAN VARIETIES OF DIFFERENT MATURITY GROUPS IN THE FOREST-STEPPE ZONE OF THE MIDDLE VOLGA REGION

Abstract

The experiments were carried out in non-watering conditions of the forest-steppe of the middle Volga region in the fields of Samara Research Institute in 2016-2018. The purpose of the research is to study the features of grain yield formation in soybean varieties of different maturity groups in order to create new varieties of Volga ecotype with high and stable grain yield. The material for the study was 29 soybean varieties of different agroecotypes and maturity groups. Standard is Samer 3. Observations and records were carried out according to the generally accepted methodology. Meteorological conditions in 2016-2018 characterized as arid, the hydrothermal coefficient varied from 0.5 to 0.7. On average, over the years of testing, the studied varieties were classified as very early – with a vegetation period of 86…90 days (8 varieties) and early 91…109 days (21 varieties), including the Samer 3 standard, ripeness groups. The high grain yield over the years of testing was in the early ripeness group - 1.95 t/ha. The sum of active temperatures above 10°C (r=+0.993…+0.999) and the amount of precipitation (r=+0.845…+0.939) had a significant impact on the duration of vegetation of both groups of ripeness in all years. A significant influence of the hydrothermal coefficient and the average daily temperature on the duration of vegetation was, revealed in 2017 and 2018. The correlation of vegetation duration with the hydrothermal coefficient was r=-0.767…-0.977, and with an average daily temperature of r=-0.902…-0.970. Among the varieties of different groups of ripeness, high seed yields (2.00…2.21 t/ha) on average over the years of testing had: Oressa, Swapa, Samer 1, Lira, Cordoba, Lisbon, Malaga