INFLUENCE OF AGROMETEOROLOGICAL CONDITIONS ON PRODUCTIONAL PROCESS OF THE NORTH ECOTYPE SOYBEAN

Abstract

Soybean has ecological adaptability caused by deep selection of this culture in terms of particular characteristics of growing zone. In this respect it demands higher standards of warmth and moistness, especially in particular “critical” periods. The research aim is to determine degree of impact of agrometeorological conditions of growing season on productional process of soybean varieties of the north ecotype. The experiments were carried out in 2017–2019 on experimental facilities of ISA FSAC VIM with varieties of Magev, Svetlaya and Georgia. Phenological observations were conducted; temperature- humidity conditions of growing season were measured. Limiting factor in particular critical periods of soybean growing and development in the Ryazan region is moisture problem. Lower threshold of dynamic daily mean temperature up to 15–17оС is formed to mid- May, but hereby drought conditions often take place. Biological temperature minimum keeps throughout growth and development, and if anomalous periods of drought or overwetting don’t begin, north ecotype soybean varieties ripe in August- breaking of September. North ecotype soybean varieties are able to form straight yield in the Ryazan region. In this respect Kasatka variety showed weak reaction on the change of agroclimatic conditions, which had shortest growing season and yield on the level of 1,00 t/ha. Georgia variety responded better to weather condition changes, its yield varied by year of research from 1,24 to 1,72 t/ha. Magev and Svetlaya varieties fall in between.