The physiological response of winter wheat to reductions in plant density

作者：Jeffrey Whaley, Debbie L. Sparkes, John Michael Foulkes, John Spink, T SEMERE, R. K. Scott · 发表于：Annals of Applied Biology · 年份：2000 · DOI：10.1111/j.1744-7348.2000.tb00048.x · 被引用次数：179 · 研究领域：Crop Yield and Soil Fertility、Plant responses to elevated CO2、Wheat and Barley Genetics and Pathology

Summary The effects of reducing the plant density of winter wheat (cv. Haven) on canopy formation, radiation absorption and dry matter production and partitioning were investigated in field experiments in 1996/97 and 1997/98. Crop densities established ranged from 19 to 338 plants m −2 . Grain yield was maintained with large reductions in plant density. At low plant densities the relative growth rate of the crop increased allowing a maintenance of crop dry matter production. An 18 fold reduction in plant density led only to a six fold reduction in green area index at the beginning of stem extension and by anthesis the difference was less than two fold. Crops grown at low plant densities increased green area per plant through increased duration of tiller production, green area per shoot and shoot survival. Main stem leaf number, phyllochron and tiller production rate were not significantly affected by plant density. Radiation use efficiency was greater at the low plant densities. We propose that better radiation distribution through the canopy and increased canopy nitrogen ratio were the causative mechanisms for this increase in RUE. As a result of increased green area per shoot and a decrease in ear production, more radiation was absorbed per shoot at the low plant densities, allowing an increase in grain number per ear from 32 to 48.