The responses of maize genotypes to growth conditions

Studies on the effects of sowing densities on maize grain yields under irrigation were performed with the aim of creating favourable conditions for plant growth and development, under which the genetic yield potential would be maximally exploited. A two-factorial trial was performed in the period 2006–2009 on chernozem, according to the splitplot method with four replicates. Four maize hybrids of different FAO maturity groups (ZP 341, ZP 434, ZP 684 and ZP 704) were observed in combination with seven sowing densities (G1 – 40,816 plants/ha, G2 – 50,125 plants/ha, G3 – 59,524 plants/ha, G4 – 69,686 plants/ha, G5 – 79,365 plants/ha, G6 – 86,286 plants/ha and G7 – 98,522 plants/ha ). The obtained results showed statistically very significant differences in maize grain yields between the studied hybrids and the sowing densities. The lowest yields were recorded for all studied hybrids at the lowest sowing density (40,816 plants/ha). The regression analysis indicated that, depending on a maize hybrid, the following maximum yields could be expected: ZP 341 - 13.25 t/ha at a sowing density of 81,000 plants/ha, ZP 434 - 13.00 t/ha at a sowing density of 75,000 plants/ha , ZP 684 - 13.83 t/ha at a sowing density of 82,000 plants/ha and ZP 704 - 12,83 t/ha at the sowing density of 77,000 plants/ha. In accordance with the rational use of seeds, high yields are obtained by sowing that provides 50,000 plants of ZP 434 /ha, 60,000 plants of ZP 341/ha and ZP 704/ha and 70,000 plants of ZP 684/ha.