Abstract:

Two maize varieties of different plant types were used to explore the effects of planting density on yield, plant agronomic traits, lodging rate and stalk puncture intensity, by setting up seven planting densities. The results showed that ‘Quanyu 217’ had the highest yield under the condition of 60000 plants/hm ² (9325.5 kg/hm²), and ‘Yuyu 30’ had the highest yield under the condition of 75000 plants/hm ² (9640.5 kg/hm²). With the increase of planting density, the number of ear rows and thousand-grain weight decreased; the plant height, ear height, and the 3^rd internode length at the base first increased and then decreased, and the 3^rd internode diameter at the base decreased. The yield of ‘Quanyu 217’ was extremely and significantly positively correlated with internode diameter, the number of ear rows, and number of grains per row, and significantly positively correlated with thousand-grain weight; the lodging rate was extremely and significantly positively correlated with the internode length, and extremely and significantly negatively correlated with internode diameter, number of ear rows, number of grains per row, thousand-grain weight and yield. The yield of ‘Yuyu 30’ was significantly positively correlated with thousand-grain weight; the lodging rate was extremely and significantly negatively correlated with internode diameter, number of ear rows, number of grains per row, and thousand-grain weight. The lodging rate increase was closely related to corn stalk puncture intensity. With the increase of planting density, the puncture intensity of the rachisinternode and the 3 ^rd internode gradually decreased, and the puncture intensity of the 3^rd internode was significantly higher than that of the rachisinternode. At the same planting density, the puncture intensity of the rachisinternode of ‘Quanyu 217’ was significantly lower than that of ‘Yuyu 30’. Therefore, the optimum planting density of the flat corn variety ‘Quanyu 217’ in this region was 60000 plants/hm ², and the optimum planting density of the compact corn variety ‘Yuyu 30’ was 75000 plants/hm ². In corn production, the appropriate planting density should be selected according to the plant type of the variety, the flat corn variety should be properly sparsely planted, and the compact corn variety can be properly densely planted.

Key words: Maize, Planting Density, Agronomic Traits, Yield, Lodging Resistance