密度对杂交棉群体冠层及光合特性的影响

目的]探讨不同密度水平杂交棉冠层结构、光合特性及与产量的变化规律,为南疆杂交棉高产高效栽培技术提供理论依据。方法]以兆丰1号和鲁棉研30号为材料研究不同密度处理下杂交棉冠层结构、光合特性及与产量的关系。结果]随着生育进程的推移,LAI先增后减,到盛花期达到最大值,18.75×10~4、26.25×10~4株/hm~2显著高于11.25×10~4株/hm~2;冠层开度先降后升,盛铃期达最小值,透光率在盛铃期表现为11.25×10~4<18.75×10~4<26.25×10~4(株/hm~2),铃对位叶Tr先降后升而其SPAD值及Pn均呈先升后降,其中18.75×10~4>11.25×10~4>26.25×10~4(株/hm~2)的规律。从产量构成因素看,单株结铃数随着密度的增加而降低;兆丰1号的单铃重呈显著性差异,鲁棉研30号差异不显著,总铃数表现出18.75×10~4>26.25×10~4>11.25×10~4(株/hm~2)的规律,衣分无差异。其中18.75×10~4株/hm~2条件下,产量最高达9 800 kg/hm~2。结论]在南疆自然生态条件下,18.75×10~4株/hm~2密度处理既能发挥杂交棉个体优势,同时具备群体优势,最终夺得高产。

Effects of Densities on the Group Canopy and Photosynthetic Production of Hybrid Cotton

Objective]The purpose of this study was to investigate the value of the group canopy structure,photosynthesis rate and their impacts on yield components.Method]Zhaofeng 1 and Lumianyan 30 were taken as the material to study the effects of 3 planting densities on the group canopy structure, photosynthesis rate and their impacts on yield components.Result]The result showed that LAI decreased with reproductive process,which was the maximum at the flowering stage and 11.25×10~4 plants /hm~2 were significantly smaller than 18.75×10~4 plants/hm~2,and 26.25×10~4 plants /hm~2.Canopy structure first decreased and then increased,which was minimum at the boll stage.The law of light transmittance at the boll stage was 11.25×10~4 < 18.75×10~4 < 26.25×10~4(plants/hm~2).The transpiration rate of opposite leaf boll at first decreased and the increased,but the SPAD and Pn showed at first increased and then decreased,and both laws were 18.75×10~4 > 11.25×10~4 > 26.25×10~4(plants /hm~2).From the yield components,with density increased,the number of bolls per plant decreased,Zhaofeng 1 showed significant difference in weight for per boll while Lumianyan 30 did not.The total boll number showed the law of 18.75×10~4 > 26.25×10~4 > 11.25×10~4(plants /hm~2).And there was no difference in lint.Yield was up to 9,800 kg/hm~2 under the condition 18.75×10~4 plants /hm~2.Conclusion]Under the natural ecological conditions of Southern Xinjiang,hybrid cotton with the 18.75×10~4 plants /hm~2 density treatment could not only express the individual superiority,but also had the group advantage.