旱区地膜与种植密度对棉花冠层光分布及产量的影响

棉花冠层光合有效辐射截获率(PARI)是影响干物质积累和产量形成的重要因素，然而对于不同覆膜方式下种植密度对棉花冠层光分布的影响尚未明确。在旱区一膜三行的机采种植模式下，设2种覆膜方式(有膜和无膜)与5种种植密度(D1:9×10⁴株/hm²,D2:13.5×10⁴株/hm²,D3:18×10⁴株/hm²,D4:22.5×10⁴株/hm²,D5:27×10⁴株/hm²),研究不同覆膜方式下种植密度对棉花冠层PARI的影响。结果表明，在全生育期，有膜处理下棉花冠层光合有效辐射(PAR)的截获能力较强；冠层PARI与种植密度呈显著正相关关系，不同种植密度之间PARI存在差异；叶面积指数(LAI)随生育进程推进呈单峰曲线。有膜处理下，不同种植密度LAI在第94～98天达到峰值；无膜处理下，不同种植密度LAI在第109～113天达到峰值；随着种植密度的增加干物质积累量减少，其生殖...

Effects of Plastic Film and Planting Density on Canopy Light Distribution and Yield of Cotton in Arid Area

The photosynthetic active radiation interception rate (PARI) within the cotton canopy plays a vital role in dry matter accumulation and yield formation.However, the effect of planting density on cotton canopy light distribution under different mulching methods has not been clarified.In this experiment, this experiment was set up in the machine harvesting planting mode of one film strip of three rows set up with two film mulching methods (PM: with film mulching, NM: without film mulching) and five planting densities (D1, 9×10⁴ plants/hm₂ ; D2, 13.5×10⁴ plants/hm₂; D3, 18×10⁴ plants/hm₂; D4, 22.5×10⁴ plants/hm₂; D5,27×10⁴ plants/hm₂), to study the effects of planting density on cotton canopy PARI under different cultivation modes.The results showed that compared with NM PM had a higher PARI in the cotton canopy during the whole growth period.The PARI was positively correlated with planting density,with variations observed among different planting densities.The leaf area index (LAI ) displayed a unimodal curve,peaking at 94-98 days for PM and at 109-113 days for all the density treatments.As the planting density increased,the dry matter accumulation decreased.With gradual decline in the contribution of repoductive organs to dry matter accumulation.The yield at a planting density of 18×10⁴ plants/hm₂ was significantly higher than those of other treatments (PM was 5 805.07 kg/hm₂,NM was 5 436.96 kg/hm₂).This study provides a theoretical basis for implementing reasonable dense planting praticess and estalishing a suitable canopy structure in arid areas.