棉花冠层对不同灌水量的反应

The Response of Cotton Canopy to Different Irrigation

讨论了北疆棉区推广棉种新陆早6号与新陆早8号在不同灌水量条件下的冠层结构特征的差异性,得出新陆早6号对限量滴灌反应不敏感,而新陆早8号对限量滴灌反应较敏感。因此在限量滴灌条件下选择新陆早6号种植较适宜。叶面积指数降低,叶片平均倾斜角度大,则群体散射辐射透过系数和群体直射辐射透过系数增加,对光能的截获率降低。由此得出了不同品种对灌水量的反应表现及理想群体冠层结构的合理指标,为增加棉花产量和提高水分利用率提供了理论依据。

This paper discussed the differences of cotton canopy structural characteristics in different irrigation conditions of Xinluzao 6 and Xinluzao 8 in North Xinjiang cotton growing region. The experiment was conducted during 2001-2002 through the whole period of Xinluzao 6 and Xinluzao 8 cultivated by under-mulch drip irrigation model. The test taking CI-110 Digital Plant Canopy Structure Imager to test canopy structure indices acquired some indexes, such as LAI, MFIA, TC, T, K. The results suggested Xinluzao 6 was not sensitive to limited drip irrigttion, and Xinluzao 8 was more sensitive. Thus Xinluzao 6 performed better at limited drip irrigation conditions. Reducing LAI and canopy light interception, increased canopy mean foliage inclination angle and transmission coefficient for diffuse penetration, transmission coefficient for radiation penetration. The results showed: LAI became bigger, but MFIA became smaller under enough irrigation and the MFIAmin showed in the middle of August. The TCmin and Tmin showed in full boll period. Reasonable K in cotton field was slowly increased from the upper to under layer. The experiment acquired the response of varieties toward different irrigation and the ideal reasonable indices of cotton canopy structure, and resulting theoretical ground for increasing cotton production and improving availability of water.