冬前高温和播期密度对小麦苗期个体及群体生长的影响

在山西临汾采用连续递增密度试验小区设计法,开展了播期密度对小麦苗期个体和群体生长的影响研究。结果表明,在冬前气温偏高的年型条件下,播种密度在225￣450万粒/hm2范围内,随着播种密度的增加株高增加,单株茎数、单株次生根数、单株绿叶数减少并存在显著性差异,而主茎叶龄则无显著性差异;播种期在9月24日￣10月4日范围内,株高、主茎叶龄和单株次生根3个性状均随播种期的推迟株高降低、主茎叶龄和单株次生根减少,单株茎数和绿叶均为9月29日播种的居多;播种期和播种密度对株高、主茎叶龄、单株茎数、单株次生根数和单株绿叶性状的变异系数影响不同。9月24日和9月29日播种的4个播种量冬前群体均分别不足1200万/hm2和超过了1200万/hm2。本试验达到壮苗和合理群体指标的组合为播期10月4日、播种量225万/hm2。

Influence of high temperature before winter and Sowing time and Density on Dynamic Growth of Individual and Population at seedling stage of wheat

Study of influence of sowing time and density on dynamic growth of individual and population was conducted in seedling stage of wheat by using the design of continuous increase in sowing density in Linfen Shanxi. The result showed: in the years with high air temperature before winter, with the increase of sowing density which is from 225 to 450 ten thousands grains /hm2, plant height increased, but Tillering per plant, Secondary root per plant and green leaves per plant decreased, there was notable difference among every densities in every traits used in this test but stem leaves, during September 24~October 04, with the deferment of seedtime, plant height, stem leaves and secondary root per plant diminished, there were more Tillering and leaves per plant when wheat was sowed on September 29. the influence of variation coefficient of per plant, stem leaves, secondary root per plant and green leaves per plant was different between sowing time and density. The population before winter was under 12 millions/hm2 sowed on September 24 and over 12 millions/hm2 sowed on September 29 in all 4 sowing quantities. The cross sowed on October 4 and with 2250 thousands /hm2 sowing quantities was ideal in this test.