种植密度对机械化收获大豆底荚高度的影响

针对山西和黄淮海大豆主产区大批育成品种品系难以适应机械化收获的现状,通过种植密度调控,研究大豆底荚高度的变化规律,分析密度与底荚高度、相关产量性状的动态关系,为育成的品种品系适合机械化收获提供理论依据。结果表明：在欧氏距离OD=8.23处将18份种质分为3类：第一类为中等分枝类型；第二类为多分枝类型；第三类为寡分枝类型。不同分枝类型品种的底荚高度随着种植密度增加变化趋势不同。底荚高度与产量最佳密度结合点：中等分枝类型为14万株/公顷和27万株/公顷；寡分枝类型12万株/公顷和27万株/公顷；多分枝类型为24万株/公顷。

Effect of Planting Density on the Bottom Pod Height of Soybean Under Mechanized Harvesting

In view of the present situation that large quantities of soybean varieties or lines in Shanxi soybean production area were difficult to adapt to mechanized harvesting, the bottleneck problem of mechanized harvesting, the height of bottom pod, was studied, to provide a theoretical basis for mechanized harvesting of soybean. By using the method of cluster analysis and correlation analysis, the variation law of soybean pod height was summarized with the regulation of planting density, and the dynamic relationship between the density and the bottom pod height and the related yield traits was analyzed. The results showed that 18 accessions of germplasm were divided into 3 categories by cluster analysis at the Euclidean distance OD=8.23: the first kind was medium branched soybean, the second was multi branched soybean, and the third was few branched soybean. The changing trend of the bottom pod height of different branch type varieties was different along with the increasing planting density. When the bottom pod height was suitable for mechanized harvesting, the best combination point of density and yield was that, the density of medium branched type was 140000/hm2 and 270000/hm2, the density of few branched type was 120000/hm2 and 270000/hm2. The density of multi branched type was 240000/hm2. The density regulates the bottom pod height, increases the yield, and makes the mechanized harvesting feasible.