Abstract:

In this study, two corn hybrids, Yuan Yu 3 of mid-maturing and medium-stem, Zheng Hong 311 of late-maturing and high-stem, were used to study the effects of agronomic traits (such as stem diameter, plant height, ear height and lodging discount rate) and yield components (such as ears number, kernels per ear, 1000-kernel weight) under different planting densities (52500, 60000, 67500, 75000, 82500 plants/hm2). Treatments were arranged in a wide-narrow-row cultivation model in high elevation region. The results showed that with the increasing of density, plant height, ear height, spike position height coefficient and lodging discount rate increased; however stem diameter, kernels per ear, 1000-kernel weight decreased; ears number and yield showed a parabola curve of first increase and later drop. In this experimental condition and similar ecological zones, Yuan Yu 3 planting density was 72000 plants per hm2, the yield reached the highest was 12430.9 kg/hm2; Zheng Hong 311 planting density was 68400 plants per hm2, the yield reached the highest was 12773.39 kg/hm2.