气候条件对冬小麦穗数的影响研究

田间试验研究气候条件对冬小麦穗数的影响结果表明,初冬剧烈降温或越冬期负积温多、极端最低气温低、降水量少,冬小麦遭受严重冻害而影响其穗数,且其影响程度取决于返青后分蘖生长发育状况。高产栽培条件下有的年份间冬小麦单位面积穗数相差较大,这与年后幼苗阶段生长时间长短、积温多少有关。生长时间长、积温多则穗数多,反之则少。穗数多的年份,适时播种的小麦是通过促进中等分蘖生长发育,进而提高成穗率而增加其穗数;晚播冬小麦则补偿了冬前积温不足,延长了幼苗阶段生长时间,巩固冬前分蘖,增加春季分蘖,并使其提前通过春化阶段,进入光照阶段,幼穗分化开始早、时间长,促进冬小麦分蘖生长发育而提高其穗数。故年后幼苗阶段生长时间长、积温多的年份,应推迟第一肥水时间,防止冬小麦群体过大、基部节间过长而造成倒伏。

Influence of climatic condition on the spike number per plant of wheat

The influence of climatic condition on the spikes number per plant of wheat in field experiments was studied.The results show that when the temperature reduces largely in early winter,the extreme temperature is low and the rain is little,the wheat will suffer from freeze injury.The influence of freeze injury on wheat is relative to the growth after it turns green.Under high-yield cultivation condition,the annual difference of spike number may be large.This is relative to the growth time of seedling after the year and the temperature.The more the growth time is,the more the number is.The right-time sowing of winter wheat can raise the rate of bearing and then raise the spike number. The late sowing of winter wheat can rise the growth time and make the verbalization come earlier.This can make the spikelet differentiation stage early and long in order to raise the spike number.If the growth time is long and the temperature is high,the fertilizer and water time should be later so as to prevent the population from growing larger,the basic joint from growing longer and the stem from lodging.