EFFECT OF PLANTING DENSITY OF DIFFERENT MAIZE HYBRIDS ON CROP GROWTH AND YIELD

Three hybrids of maize of Pioneer Company (P9241, P9900 and P0023) grown at different plant densities (40000, 46000, 56000, 69000 number per ha) were studied in the experimental field of Agricultural University of Plovdiv in 2015 and 2016. The purpose of this study was to trace the influence of sowing density of maize hybrids on growth and yield. The experiments were carried out by split-plots method. The experimental areas were fertilized with a nitrogen fertilizer rate of 240 kg/ha - 1/2 CO(NH2)(2),applied in the 5-6 leaf stage of the plant and 1/2 NH4NO3 ,applied into the 10th leaf stage. A hybrid P9900 has the highest plants at the end of vegetation. There was no significant difference between variants with plant densities - from 279.4 cm (40000 plants/ha) to 284.4 cm (56000 plants/ha). Height of plants of hybrid P9241 was the smallest - 260.5 cm at a sowing density of 40000 plants/ha. The highest yield between 3 hybrids was obtained at a sowing density of 69000 plants per ha. Hybrid P9241 showed yield of 13800 kg/ha, while hybrid P9900 - 14257 kg/ha.