倒伏是当前玉米增密增产栽培的重要制约因素之一。以玉米杂交种隆平206和凤玉906为供试材料，设置60 000株?hm-2、75 000株?hm-2、90 000株?hm-2三个密度处理，研究不同种植密度条件下夏玉米基部节间相关性状和倒伏之间的关系。结果表明，隆平206生育后期植株倒伏率随密度增加而增大，凤玉906在低密度条件下倒伏率为0，其他2个密度条件下倒伏率均小于5%。随着种植密度的增加，玉米植株基部节间直径逐渐变小，茎粗系数减小，同时基部节间鲜重、干重逐渐减少，基部节间抗折力逐步降低，两品种三个基部节间均表现类似趋势。品种间比较，在同一密度处理下，虽然凤玉906基部节间抗折力显著低于隆平206，但茎秆基部节间干重显著高于隆平206。说明与其它基部节间性状相比，玉米茎秆基部节间干重对植株倒伏有重要影响。结合玉米产量水平，隆平206较适种植密度为60 000 ~ 75 000株?hm-2，凤玉906较适种植密度为75 000 ~ 90 000株?hm-2。
英文摘要:
The lodging is one of the major determinants of the high-yield cultivation of summer maize under high density currently. Two maize hybrids, Longping 206 and Fengyu 906 were grown in this study. To investigate the relationship between lodging and characteristics of basal internodes, a density experiment was designed with three levels of 60 000 plants?hm-2, 75 000 plants?hm-2 and 90 000 plants?hm-2. The results showed that the lodging rate increased significantly with increasing plant density in Longping 206. The lodging rate of D1 treatment was 0, and the lodging rates of D1 and D2 treatments were less than 5% in Fengyu 906. With the increase of planting density, the stem diameter coefficient decreased significantly. Fresh weight, dry weight, diameter and the snapping resistance of basal internodes decreased gradually at the same time. Three basal internodes showed a similar trend in two hybrids. Under the same density treatment, the snapping resistance of basal internodes of Fengyu 906 were significantly lower than that of Longping 206. However, the dry weight of stem internodes of Fengyu 906 were significantly higher than that of Longping 206. The results suggested that the dry weight of basal internodes had great effect on the lodging of summer maize compared with other basal internodes characters. Combined with the yield of maize hybrids, the suitable planting densities were from 60 000 plants?hm-2 to 75 000 plants?hm-2 of Longping 206 and from 75 000 plants?hm-2 to 90 000 plants?hm-2 of Fengyu 906, respectively.
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