摘要
夏直播棉花能够在较短生育期内获得与常规模式相当的产量,但其产量高效形成的机理及其与冠层微环境的关系仍不清楚。因此,本试验采用完全随机区组设计,设置6个种植密度(7.50株m^(–2)、8.25株m^(–2)、9.00株m^(–2)、9.75株m^(–2)、10.50株m^(–2)和11.25株m^(–2)),于2022-2023年在湖北武汉进行了大田试验。采用温湿度仪记录从现蕾到拔杆期间冠层温度和湿度,冠层分析仪测定结铃期冠层不同高度光辐射强度,手工收获计产。结果表明,棉花产量随种植密度增加先升后降,其中9.75株m^(–2)最高(籽棉3246.5 kg hm^(–2)、皮棉1203.2 kg hm^(–2)), 2年平均较7.50株m^(–2)提高(15.0%和17.8%)。冠层日均温、最高温、最低温随种植密度增加而降低,而冠层相对湿度、最高湿度、最低湿度随种植密度增加而增加。冠层透光率,水平方向呈“V”型分布,棉行中间最大;垂直方向中下部(离地10^50cm)随种植密度增加而减小,上部(离地50^70cm)随种植密度增加而增大。群体叶面积指数随种植密度增加先升后降,其中9.75株m^(–2)最高,2年平均为2.6。相关分析表明,棉花产量随冠层日均温和最高温升高而降低,随冠层相对湿度和最高湿度增加而增加;随冠层中下部透光率增大而减小,随上部透光率增加而增大。综上,棉花夏直播种植模式,适当增加种植密度(9.75^11.25株m^(–2))有利于提高单位面积成铃数,改善冠层微环境,如冠层透光率70cm处85%以上,50 cm处37%^40%,30 cm处14%^16%,10 cm处9%以下,冠层温度26.5^27.0℃,冠层湿度74%^77%,从而提高棉花产量。
The yield of cotton under summer direct seeding can be comparable to that of conventional cotton in a short growing period.However,the mechanisms behind high yield formation and its relationship with the canopy microenvironment remain unclear.Therefore,this experiment employed a completely randomized block design,with six different planting densities(7.50,8.25,9.00,9.75,10.50,and 11.25 plants m^(-2)).The field experiment was conducted in Wuhan from 2022 to 2023.Temperature and humidity within the canopy were recorded using an automated meter,while light radiation intensity at various heights of the can-opy during boll setting stage was measured using a canopy analyzer.Cotton was manually harvested to calculate the yield.The results indicated that cotton yield initially increased and then decreased with increasing planting density.Among them,the highest yield(3246.5 kg hm^(-2) of seed cotton and 1203.2 kg hm^(-2) of lint)was observed at a density of 9.75 plants per square meter,which was significantly higher than the yield at 7.50 plants m^(-2)(15.0%and 17.8%higher)over the two years.As planting density in creased,the average daily temperature,maximum temperature,and minimum temperature within the canopy decreased,while relative humidity,maximum humidity,and minimum humidity increased.Canopy light transmittance exhibited a“V”shape hori-zontally,with the maximum at the middle of the cotton row.Vertically,light transmittance in the middle and lower part(10-50 cm above the ground)decreased with increasing planting density,while the upper part(50-70 cm above the ground)showed an in-crease.Population leaf area index initially increased and then decreased with planting density,with the highest value observed at 9.75 plants m^(-2),averaging 2.6 over the two years.Correlation analysis showed that cotton yield decreased with the increase of average daily temperature and maximum temperature,while it increased with the increase of relative humidity and maximum humidity.Cotton yield decreased with increased light transmittance in the middle and lower part of the canopy,but increased with increased light transmittance in the upper part of the canopy.In conclusion,under summer cotton direct seeding,appropriately increasing the planting density(9.75-11.25 plants m^(-2))is beneficial for increasing boll number per unit area and improving the canopy microenvironment,ultimately increasing cotton yield.The optimal canopy microenvironment conditions are as follows:canopy transmittance of above 85%at 70 cm,37%-40%at 50 cm,14%-16%at 30 cm,and below 9%at 10 cm;canopy tempera-ture of 26.5-27.0℃;and canopy humidity of 74%-77%.
作者
彭杰
谢晓麒
张钊
姚晓芬
邱深
陈丹丹
顾晓娜
王玉洁
王晨晨
杨国正
PENG Jie;XIE Xiao-Qi;ZHANG Zhao;YAO Xiao-Fen;QIU Shen;CHEN Dan-Dan;GU Xiao-Na;WANGYu-Jie;WANG Chen-Chen;YANG Guo-Zheng(College of Plant Science and Technology,HuazhongAgricultural University,Wuhan 430070,Hubei,China)
出处
《作物学报》
CAS
CSCD
北大核心
2024年第9期2371-2382,共12页
Acta Agronomica Sinica
基金
湖北洪山实验室项目(2021hszd006)资助。
关键词
夏直播
产量
冠层微环境
种植密度
叶面积指数
summer direct seeding
yield
canopy microenvironment
planting density
leaf area index
