适期晚播对不同密度冬小麦产量和茎秆抗倒性能的调控效应

(方法)本试验在宽幅播种条件下,以大穗型冬小麦品种泰农18为材料,设计常规播期10月10日和适期晚播10月20日2个播期处理,各播期下分别设置225、375和525万/公顷3个种植密度,(目的)研究了播期和密度互作对冬小麦产量及产量形成、茎秆重心高度、基部节间机械强度和茎秆抗倒指数的影响,以期明确适期晚播对密植高产冬小麦产量和茎秆抗倒性能的调控效应。(结果)研究结果表明,播期和种植密度显著影响冬小麦的产量和抗倒性能。各播期间适度密植(375万/公顷)可通过提高穗数获得高产,且在两播期间无显著差异。适度晚播显著提高各密度冬小麦抗倒指数；在晚播条件下,随种植密度增加,小麦重心高度提高的幅度、基部节间机械强度降低的幅度显著低于常规播期,从而使得适期晚播密植小麦的抗倒能力仍可维持在较高水平。(结论)适度密植小麦可通过适期晚播平衡其产量和抗倒能力,本试验条件下,采用375万/公顷的种植密度,在10月20日播种,可协同实现高产、稳产。

Effect of Late Sowing on Lodging Resistance and Grain Yield of Winter Wheat at Different Densities

Regular sowing date (October 10) and moderate late sowing date (October 20) were designed in this study using a large-spike winter wheat variety‘( Tainong 18’) as the experimental material. Furthermore, on each sowing date, three planting densities were designed at 2.25, 3.75 and 5.25 million plants/hm2 respectively. The interactive effects of sowing date and planting density and their interactions on the grain yield, culm height at the center of gravity (CHCG), culm mechanical strength of the second base internode (CMS) and the culm lodging resistance index (CLRI) of winter wheat were studied to clarify the regulation of late sowing on grain yield and culm lodging resistance of high-yield winter wheat. The results showed that the interactive effect of sowing date and planting density significantly influenced the yield and lodging resistance of winter wheat. Properly increasing planting density to 3.75 million plants/hm2 could achieve high yield by improving the number of spikes during each sowing period, and there was no significant difference between the two sowing dates. Moderate late sowing increased the CLRI of the winter wheat enormously in various plantingdensities. Under the late sowing condition, with the increase of planting density, the improvement of the CHCG and the reduction of the CMS were obviously lower than those of the conventional sowing date. Therefore, the CLRI of winter wheat at relatively high density could still be maintained at a high level. The winter wheat planted at a relatively high density could balance its high grain yield and high lodging resistance by means of sowing relatively late. In this research, the high yield and the stable production could be achieved simultaneously when sowing on October 20 at the planting density of 3.75 million plants/hm2.