施氮量和施氮时期对冬小麦幼穗小花发育及产量的影响

以兰考矮早八(大穗型)和豫麦49-198(多穗型)2种冬小麦品种为材料,研究大田种植条件下3个施氮量和5个施氮时期(基追肥质量比为5∶5)对2种穗型冬小麦幼穗总小花和完善小花发育及产量构成因素的影响。结果表明,与N0和N360处理相比,N180处理的小花发育进程较为平缓。在全生育期施纯氮180kg/hm2条件下,多穗型品种由于幼穗小花发育快、周期短,故延迟追氮有利于完善小花的发育;大穗型品种则由于幼穗小花发育周期较长表现规律不明显。随氮肥施用量增加,2种穗型冬小麦品种的籽粒产量均呈先增加后减少的趋势,2品种均表现施纯氮180 kg/hm2处理籽粒产量最高,且均以返青后20 d追氮效果最好。在较高土壤肥力条件下,施纯氮180 kg/hm2,基施氮肥50%,并于返青后20 d追施50%,能够显著增加冬小麦的完善小花数目,提高穗粒数和千粒质量,进而获得较高籽粒产量。

Effection of Rate and Period of Nitrogen Application on the Floret Development and Grain Yield of Winter Wheat

Under the field conditions,three pure nitrogen rates(0,180 and 360 kg/hm2) and five application stages during the whole growth period(50% basal fertilizer and 50% postponing topdressing) were designed in this experiment to study the effects of nitrogen application rates and periods on the floret development and grain yield of large-spike cultivar Lankaoaizao 8 and multi-spike cultivar Yumai 49-198.The results showed that the process of the floret development of two spike-type cultivars under 180 kg /hm2 nit...