麦茬复种饲料油菜的播种量对其生长性状的影响

Effect of planting density on growth properties of rapeseed in wheat/silage rape multiple cropping

通过田间小区试验,研究在麦茬复种条件下,不同播种量的饲料油菜株高、鲜重、干重、叶面积指数和净同化率的动态变化规律。结果表明,麦茬复种油菜地上生物产量的累积规律为幼苗期缓慢,蕾薹期最快,开花后减缓,基本符合"S"型生长曲线。高密度播种能极显著提高复种油菜地上部干重、鲜重及其日生长量,以播量11.5kg/hm2处理为最优。增加播种量能明显提高复种油菜叶面积指数以及群体同化率。不同播种密度下,油菜生长期与其生长指标数学方程拟合为:干重y=k/(1+a-ebx),叶面积指数y=a+bx+cx2,其它指标均为y=a+bx+cx2+dx3,其拟合度均达极显著水平。

In this paper,a field experiment was conducted to study the dynamic effects of different sowing density on plant height, dry and fresh weight, leaf area index and net assimilation rate of rape seed in wheat stubble multiple rape cropping. The results showed that aboveground biomass accumulation can be described by ＂S＂ developing curve that was the seedling stage slower heightening and the buds stage quickest heightening and again slower heightening after blooming stage in wheat stubble multiple rape. Increasing sowing density significantly increased dry weight and fresh weight along with their daily growth rate of multiple-cropping rape with wheat,11.5 kg/hm^2 sowing density was the optimal. Increasing sowing density obviously improved leaf area index and net assimilation rate of wheat stubble multiple cropping rape. Using mathematics equation simulated and compared the correlativity of rape growth stages and indexes in different sowing density,the results of simulated showed that dry weight was y=k/（1＋ae^-bx）, and leaf area index was y=a＋bx＋cx^2,other indexes all accorded with y=a＋bx＋cx^2＋dx^3. The model simulation degree was all extremely remarkable.