作物学报2024，Vol.50Issue(9)：2371-2382,12.DOI:10.3724/SP.J.1006.2024.34205
夏直播棉花产量与冠层微环境的关系
Relationship between cotton yield and canopy microenvironment under summer direct seeding
摘要
Abstract
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%.关键词
夏直播/产量/冠层微环境/种植密度/叶面积指数Key words
summer direct seeding/yield/canopy microenvironment/planting density/leaf area index引用本文复制引用
彭杰,杨国正,谢晓麒,张钊,姚晓芬,邱深,陈丹丹,顾晓娜,王玉洁,王晨晨..夏直播棉花产量与冠层微环境的关系[J].作物学报,2024,50(9):2371-2382,12.基金项目
本研究由湖北洪山实验室项目(2021hszd006)资助.This study was supported by the Hubei Hongshan Laboratory Project(2021hszd006). （2021hszd006）
