不同密度棉花群体冠层光合有效辐射的时空分布特征  

Spatial and Temporal Distribution of Photosynthetic Active Radiation Within Cotton Canopy

作　　者：吴杨焕 贾彪[2] 李杰[1] 杨平[1] 柴顺喜 陈锐[1] 张斌[3] 马富裕[1] 

机构地区：[1]石河子大学农学院/新疆生产建设兵团绿洲生态农业重点实验室,新疆石河子832003 [2]宁夏大学农学院,银川750021 [3]新疆农垦科学院,新疆石河子832000

出　　处：《西北农业学报》2016年第1期57-63,共7页Acta Agriculturae Boreali-occidentalis Sinica

基　　金：国家科技支撑计划(2012BAD41B02);新疆省维吾尔自治区研究生创新基金(XJGRI2013064)~~

摘　　要：以北疆2个棉花主栽品种‘新陆早50’和‘鲁棉研24’为试验材料,测定高(24.0万株/hm2,D1)、中(17.6万株/hm2,D2)、低(8.25万株/hm2,D3)3个不同密度下,棉花铃期冠层光合有效辐射(PAR)时空分布状况。结果表明:各处理干物质量和蕾铃数与棉花叶面积指数在纵向空间分布上有良好的线性关系;冠层内PAR透光率从顶部向下逐级递减,冠层上部递减幅度迅速,中、下部递减缓慢;PAR透光率随密度的增加而递减,随向下累积叶面积指数(LAI)的增加呈指数递减,群体消光系数K日变化表现为早晚较高,中午较低;D2条件下透光率优于D1和D3,有利于增加蕾铃数,低密度条件虽然有利于增加单株蕾铃数,却不利于单铃质量的增加,最终D2密度条件下‘鲁棉研24’和‘新陆早50’棉花实收籽棉产量均达到最高,分别为4 852.27kg/hm2和5 167.73kg/hm2。Taking two main cotton cultivars‘Xinluzao 50＇and ‘Lumianyan 24＇planted in Northern Xinjiang as experimental materals,three kinds of plant densities such as high（240×103 plants/hm2,D1）,middle（176×103 plants/hm2,D2）and low（82.5×103 plants/hm2,D3）were set up in 2014,and we also measured the spatial distribution of photosynthetic active radiation（PAR）at different heights of cotton canopy with a Li-250 Alight meter.The results showed that at the boll stage,cotton leaf area at each layer of the canopy was linearly related to cotton dry mass,bud number,and boll number.Canopy PARtransmittance decreased from the top to the bottom of cotton canopy.The sharp decrease of PARoccurred at the upper canopy layer.The decreases of PARbecame smaller at the middle and lower layers of the canopy.The average PARtransmittance decreased as plant density increased.The average PARtransmittance exponentially decreased with cumulative increase of LAI.The extinction coefficient K was higher in the morning and afternoon,and lower in afternoon.The PARtransmittance was greater in the 176×103 plants/hm2 treatment than in either the 240×103 plants/hm2 treatment or the 82.5×103 plants/hm2 treatment.Greater PARtransmittance under the 176×103plants/hm2 treatment helped to increase the number of buds and bolls.Under the treatment of D2（176×103 plants/hm2）the yields of seed cotton of two cultivars‘Lumianyan 24＇and‘Xinluzao 50＇were the highest,and its yields were 4 852.27kg/hm2 and 5 167.73kg/hm2,respectively.

关 键 词：棉花 光分布 透光率 光合有效辐射 消光系数 

分 类 号：S562[农业科学—作物学]