The influence of hybrids and sowing term on yield and dry down of corn grain

The dry down rate of corn grain during maturation is influenced by a large number of environmental factors and properties of hybrids, and has a major effect on corn, reaching its full maturity. This is especially important for the timely soil tillage and planting of the next culture. The aim of this research was to determine the yield and dry down rate from corn grains depending on the hybrid and the sowing term, in the agro ecological conditions of South Serbia (Leskovac). For this purpose, an experiment was made during 2016 and 2017 on the territory of the municipality of Leskovac. Soil type was alluvium. The trial was planned according to the schedule of divided land plots, set up in three repetitions. This included 6 hybrids of different FAO maturity groups and three differing sowing terms. The results of the study show that the average content of water in the grain in physiological and technological maturity, at all the hybrids and sowing terms were in 2016 significantly lower than in 2017. The highest average yields in 2016 were achieved with hybrids of the FAO maturity group 600, in the 2nd and 3rd sowing term, while in 2017, the highest yields were recorded with hybrids of the FAO maturity group 500, during the 1st and 2nd sowing term. The average rate of dry down in 2016, in all hybrids, was the highest recorded in the 1st sowing term, and in the year 2017, in 2nd and 3rd sowing term. The most intense dry down rate period in both years, at the hybrids of the FAO maturity group 400 was in the second and third week of physiological maturity, while in FAO maturity hybrids groups 500 and 600 in the third and fourth week of physiological maturity