日光温室黄瓜群体结构参数及群体内辐射分布分析

为研究作物群体结构与环境要素的关系，观测了日光温室内黄瓜不同生育时期的群体结构参数和群体内太阳总辐射的水平分布和垂直分布。发现叶面积指数、叶面积密度、叶倾角、叶方位角等结构要素在不同生育时期有明显的变化：随生育的进展，叶面积指数稳定增加，叶面积密度生育前期明显上升、后期有所下降，最大叶面积密度所在高度随黄瓜生长逐渐上移；叶倾角分布主要以水平叶为主；叶方位角以偏南居多，偏北叶所占比例较少；不同黄瓜品种间叶方位角和叶倾角也存在差异。这些变化与差异对黄瓜群体的辐射分布有重要影响，也直接影响群体叶的光合速率，此结果可为建立黄瓜群体辐射分布模型进一步优化日光温室结构，建立日光温室内作物生长模型、环境调节控制策略等提供理论依据，另外，对植株的调控技术(如整枝打杈技术等)也有一定的参考意义。

Analysis of architectural parameters and solar radiation distribution in cucumber canopy in sunlight greenhouse

In order to study the relationship between plant canopy architecture and environmental elements in sunlight greenhouse, cucumber architectural parameters and the spatial distributions of global solar radiation in canopy were observed. The results showed that leaf area index, leaf area density, leaf zenith and azimuth angles varied obviously with growth stages and differed from varieties. Leaf area index increased steadily as the growth stages went on, and leaf area density increased at the early stage and decreased at the late stage. The height where much leaf area density was located was going up as cucumber developed; The main leaf zenith angle distributions were horizontal and the most leaf azimuth angles were leaning to the south. The differences were found to be related closely to spatial distributions of global solar radiation in canopy, also influencing photosynthetic rate. The results were anticipated to be useful in modeling the radiation transfer into cucumber canopy, developing the crop model, controlling greenhouse environment, reforming greenhouse architectural structure and so on.