留苗密度对直播油菜产量及机械收获的影响

目的]找出最佳直播播量及大田留苗密度处理,为实现大面积机收推广提供科学依据。方法]对直播油菜设置4种播量及留苗密度处理,调查各处理产量构成、实产、抗逆性(如菌核病、抗倒性)、开花结荚历期。结果]随着播量的增加,油菜个体生长发育受到影响,有效降低了油菜株高,提高了油菜第1分枝节位,利于油菜分枝向上集中、油菜株型的塑造和机械化收割,但播量增加,限制了油菜个体的发育,使油菜分枝数减少,有效角果数、每角粒数变少,千粒重下降,不利于油菜产量增加。结论]在安徽沿江地区,油菜直播量为3 750 g/hm~2、大田留苗密度约37.5万/hm~2的处理,比较适合油菜机械化收割。

Effects of Seedling Density on Direct Seeding Rape Yield and Mechanical Harvest

Objective] The aim was to find out the optimal direct seeding quantity and field seedling density, to provide scientific basis for real-izing large area mechanical harvest. Method] Setting up 4 sowing rate and seedling density , yield components, actual yield, stress resistance (such as stalk break, lodging resistance), flowering and fruiting period in each treatment were investigated.Result] The increase of sowing rate could effectively reduce rape plant height, improve nodes order of the first branch, which is conducive to rape branches upward concentrat-ed, shaping of plant type and mechanized harvesting;while the increase of sowing rate restrict rape individual development , reduce branches, ef-fective pods, grains per pod, 1 000-grain weight, which is not conductive to the increase of rape production.Conclusion] In the area along the Yangtze River in Anhui Province, the rape seeding rate is 3 750 g/hm2 , and the seedling density of the field is about 375 thousand /hm2 , which is more suitable for mechanical harvest of rape .