The duration of the growing season is an important, adaptively significant indicator for any crop variety. In wheat breeding, a reliable criterion for determining the maturity group of a variety is the ear formation period. The purpose of the study was to determine the ear formation period of soft winter wheat varieties of various ecological and geographical origins in the conditions of the forest steppe of the Middle Volga region, and also to determine its effect on yield. Among the studied

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... ieties of wheat from the world collection, German varieties were characterized by late ripeness, wheat from China, Japan, Bulgaria and the North Caucasus region of Russia by early ripeness and mid-ripeness, - varieties from the Siberian region of the country by mid-ripeness. Ukrainian cultivars were represented by wheat of different maturity groups. It has been found in the studies that under varying environmental conditions in different years early ripening, mid-early, mid-ripening and mid-late wheat can be highly productive. A well selected system of ripening varieties of soft winter wheat (65–70 % mid-ripening, 25 % mid-early and early-ripening, 5–10 % mid-late) will make it possible to use favorable environmental factors with great efficiency and withstand environmental stresses.