Influence of planting density on the yield,lodging rate and mechanical harvesting quality of summer corn Shangdan 1967
In order to clarify the suitable planting density of corn variety Shangdan 1967 in the eastern Henan Province,as well as the impact of planting density on lodging and mechanical harvesting quality,3 planting densities of 60 000 plants/hm2(D1),75 000 plants/hm2(D2),and 90 000 plants/hm2(D3)were set up in the experiment,the effects of planting density on the yield,lodging,and mechanical harvesting quality indicators of Shangdan 1967 were analyzed.The results showed that with the increase of planting density,the yield of Shangdan 1967 showed a trend of first increasing and then decreasing.When the density increased from 60 000 plants/hm2 to 75 000 and 90 000 plants/hm2,the yield growth rates were 12.4%and 9.7%,respectively.The stem bending rate and total lodging rate increase with the increased of density.The crushing rate,impurity rate,and total loss rate of mechanical harvesting quality indicators all showed an increasing trend with the increase of planting density.Through the correlation analysis between lodging rate and mechanical harvesting quality indicators,it was found that there was a positive correlation between total lodging rate and crushing rate(P<0.01),a positive correlation with total loss rate(P<0.05),and no statistically significant correlation between total lodging rate and impurity rate(P>0.05).Taking into account factors such as yield,lodging,and mechanical harvesting quality,the suitable planting density for Shangdan 1967 in the eastern Henan region was 75 000 plants per hectare.