THE GRAIN YIELD OF MAIZE HYBRIDS DEPENDING ON THE RIPENESS GROUP AND STAND DENSITY IN THE CONDITIONS OF THE FOREST STEPPE OF UKRAINE

Abstract

Corn grain production is a complex and costly process with timely and high-quality execution of all technological operations. In production conditions, the cultivation of new hybrids with high productivity potential is the key to stabilizing grain production. The studies have shown that the duration of the interphase periods of corn plants was significantly influenced by the hybrid composition and much less by the stand density. The shortest vegetation period was noted in the hybrid DKC 3050 – 111 days. In the hybrid DKC 3730 and DKC 4351 with the FAO number 280-350, the growing season was 118-119 days. The longest vegetation period was in the hybrid DKC 4608 (FAO 380) – 122 days. The conducted studies showed that the pre-harvest moisture content of the grain depended on the hybrid and the density of the plants. In particular, it was established that grain moisture increases with an increase in the number of FAO. Thus, the lowest humidity during the years of the research was the hybrid DKС 3050 with the FAO number 200 – 20,4-21,2%. The pre-harvest humidity in the hybrid DKС 3730 (FAO 280) was 21,6-22,5%, in the hybrid DKС 4351 (FAO 350) – 25,1-25,7%. The highest pre-harvest humidity was recorded in the hybrid DKС 4608 with FAO number 380 – 28,7-29,5%. It should be noted that the pre-harvest moisture content of the grain increased as the crop thickened and was the lowest one at a density of 60,000 pieces per ha and increased by 0,6-0,9% when thickening up to 90,000 pieces per ha. According to the research results, it was established that the yield of corn hybrids ranged from 8,76 to 11,44 t/ha. The highest yield of the DKC 3050 hybrid was obtained at a density of 90,000 pieces/ha – 9,29 t/ha. Hybrid DKC 3730 had the highest yield at a density of 80,000 pieces/ha – 10,78 t/ha. In the hybrid DKC 4351, the highest yield was obtained at a density of 90 thousand pieces/ha – 11,10 t/ha. It should also be noted the low plasticity of this hybrid to changes in stand density, since the yield at a density of 70-90 thousand pieces/ha was approximately the same in all years of the study. The maximum yield of corn grain was obtained in the hybrid DKC 4608 at a density of 90 thousand pieces/ha – 11,38 t/ha. The analysis of the conducted studies indicates the feasibility of growing mid-ripe corn hybrids DKC 4531 (FAO 350) with a density of 70 thousand units/ha and DKC 4608 (FAO 380) with a density of 80-90 thousand units/ha.