中文摘要：

叶面积指数是光合作用驱动的作物生长模型以及冠层蒸腾模型所需的重要作物参数，温度和辐射是影响叶片生长的重要环境因子.通过不同定植期、不同品种、不同地点的试 验，定量分析了温室甜椒出叶数、叶片长度和叶面积指数与温度和辐射的关系，构建了温室 甜椒叶面积模型，并利用独立的试验资料对模型进行了检验.结果表明：甜椒出叶数与出苗 后累积辐热积呈指数函数关系；叶片长度与出叶后累积辐热积呈负指数函数关系；甜椒出叶 数、叶片长度和叶面积指数的模拟结果与实测值之间的决定系数R^2分别为0.94、0.89、0.93，其回归估计标准误RMSE分别为3.4、2.15 cm、0.15.该模型能够利用气温、辐射、 种植密度和出苗日期准确地预测温室甜椒叶面积指数动态，且模型参数少、实用性强，可以为温室甜椒生长模型和蒸腾模型提供必需的叶面积指数动态信息.

英文摘要：

Leaf area index （LAI） is one of the most important crop parameters in photosynthesisdriving crop growth simulation model and canopy evapotranspiration simulation model, while air temperature and radiation are the important climate factors affecting crop leaf growth. In this paper, experiments with different sweet pepper （Capsicum annuum L. ） cuhivars and sowing dates were conducted in greenhouse to quantitatively analyze the relationships of the number of unfolding leaves per plant, the number of old leaves removed per plant, and the length of each leaf with air temperature and radiation. Based on these quantitative relationships, a leaf area simulation model for greenhouse sweet pepper was developed, and the independent experimental data were used to validate the model. The results showed that the number of unfolding leaves per plant was a positive exponential function of the product of thermal effectiveness and PAR （TEP） accumulated after emergence, and the length of each leaf was a negative exponential function of the TEP accumulated after emergence. The coefficient of determination （ R^2 ） and the root mean squared error （RMSE） between simulated and measured leaf number, leaf length, and LAI were 0. 94, 0.89, and 0. 93, and 3.4, 2. 15, and 0. 15, respectively. The model could use air temperature, radiation, planting density, and emergence date to satisfactorily predict the LAI of greenhouse sweet pepper, and supply required LAI information for the sweet pepper growth and canopy evapotranspiration simulation models.