大麦芒对籽粒产量的作用

Effect of Barley(Hordeum vulgate)Awns on Grain Yield

Awn-cutting and defoliation experiments in barley made from 1982 to 1987 showed that the effect of different photosynthetic organs on grian yield followed the fol- lowing order:awn>flag leaf blade>second leaf blade from the top>third leaf blade from the top.The effect of awn varied with barley types and ecoclimatic conditions during kernel filling stage.It was greater in six-rowed barley than in two-rowed bar- ley.The contribution of awn to grain weight in the years with higher temperature, abundant sunlight and less rainfall is greater than that in the years with lower tempera- ture.insufficient sunlight and more rainfall.At the kernel filling stage.spraying liquid fertilizer of urea mixed with KH_2PO_4 onto awns could improve photosynthetic capacity considerably.with an increase of 1.3-3.4g per 1000 grains.The principal machanism of the excellent contribution of awn to grain yield lies in their complex structure of assimilation cells.larger photosynthetic area and higher content of chlorophyll.