播期播量对小麦越冬死苗的耦合效应

目的]为易发生冻害地区的冬小麦防冻提供科学依据。方法]以鲁麦6号为试材,采用D-饱和最优设计法研究播期和播量耦合与小麦越冬死苗的关系,建立了小麦越冬死苗的数学模型。结果]10月25日播种,基本苗120万/hm2小麦的越冬死苗率最低,为10.8%。播期(冬前积温)、基本苗对鲁麦6号越冬死苗率的作用均为正效应,且播期为第一位,播量为第二位。10月1日播种,基本苗390万/hm2,死苗率最大为93.19%;10月6日播种,基本苗344.1万/hm2,死苗率最大为65.97%。10月16日播种,基本苗302.6万/hm2,死苗率最大为49.65%。10月25日播种,基本苗229.1万/hm2,死苗率最大为37.46%。结论]播期对小麦越冬死苗率的作用占第一位,播量的影响不容忽视。在栽培上首先要适当晚播,再就是适当降低播量。

Coupling Effect of Sowing Date and Sowing Rate on the Wheat Seedlings Death in Overwintering

Objective] The purpose of this study was to supply scientific foundation for freezing prevention of winter wheat in the area where freezing damage easily occurred. Method] With Lumai6 as tested material, D-saturation optimum design was used to study the relationship between coupling of sowing date and sowing rate and wheat seedlings death in overwintering, and the mathematic model of wheat seedlings death in overwintering was established. Result] The seedlings death rate in overwintering of wheat with 1.2×106/hm2 basic seedlings sowed on 25th October was lowest, being 10.8 %. The effects of both sowing date (accumulated temperature before winter) and basic seedlings on the seedlings death rate in overwintering of Lumai6 were positive, and the first was sowing date and the second was sowing rate. The maximum seedlings death rate was 93.19 % for 3.90×106/hm2 basic seedlings sowed on 1st October, 65.97 % for 3.441×106/hm2 basic seedlings sowed on 6th October, 49.65 % for 3.026×106/hm2 basic seedlings sowed on 16th October, and 37.46 % for 2.291×106/hm2 basic seedlings sowed on 25th October. Conclusion] The effect of sowing date on wheat seedlings death in overwintering occupied the 1st position and that of sowing rate was unnegligible. The suitably late sowing and reduced sowing rate should be used in cultivation.