密度和施肥水平对双低油菜苏油1号产量及分枝习性的影响

密度和施肥水平两因子对苏油1号产量及分枝习性影响的研究结果表明：（1）移栽11．25万株/hm2，施纯氮270kg/hm2是适宜苏油1号的种植密度和施肥处理，产量达到3452.0kg/hm2.(2)产量结构因子以单位面积有效角果数对产量的影响较大，其次为千粒重和每角粒数。（3）随密度和施氮量增加，单位面积有效果数呈先增后减的趋势，千粒重与施氮量关系密切，但过量施氮则降低千粒重，（4）单位面积为枝数多，分枝角果数多和分枝籽粒多是苏油1号的高产表现。

Effect of density and nitrogen on the yield and branch characteristics of double-low rapeseed (Brassica napus L.) Suyou No.1

This experiment was conducted to investigate the effect ofplantation density and nitrogen application on the yield and branch characteristics of double-low rapeseed Suyou No.1. The results showed as follows: (1) The highest yield in this experiment appeared in the treatment with density of 11.25×104 plants per hectare and nitrogen of 270kg per hectare. (2) Yield components showed that number of effective pods per hectare was more important than 1000-seeds weight and number of seed per pod. (3) The number of effective pods increased firstly and then decreased as density and nitrogen increased. There were close relationship between 1000-seed weight with amount of nitrogen applied, the 1000-seed weight was decreased when nitrogen applied over 225kg／hm2. (4) High yielding population of Suyou No.1 had more branches, more pods per branch and more seeds produced by each branch.