中文摘要：

为了探讨作物全生育期内累积蒸发蒸腾量的变化规律，采用Logistic曲线建立了夏玉米、设施栽培番茄和西瓜的累积蒸发蒸腾量随生育时间变化的模拟模型，并通过Logistic曲线的不同阶段分析了作物生育期内的需水规律．结果表明：玉米、番茄和西瓜的全生育期累积蒸发蒸腾量呈现出符合Logistic曲线的“慢—快—慢”的变化规律，采用Logistic曲线模拟大田和设施栽培作物累积蒸发蒸腾量是可行的；与FAO推荐的生育进程划分结果相比，根据Logistic曲线对大田作物玉米的生育进程划分结果相差不大，而设施栽培番茄和西瓜的生育进程划分结果有较大的差异．

英文摘要：

A simulation model of crop accumulative evapotranspiration varying during the full growth period was established for field cultivation of summer maize and protective cultivation of tomato and watermelon by use of the Logistic curve, and the regularities of water demand by crops were analyzed by means of different stages of the Logistic curve. The result shows that the accumulative evapotranspiration of summer maize, tomato, and watermelon during the growth period is in conformity with the Logistic curve with the rhythm of ＂slow-quick-slow＂, therefore it is feasible for the Logistic curve to simulate the crop accumulative evapetranspiration in field cultivation and protective cultivation. As compared with the result recommended by FAO, the result of growth period division for field cultivation of Summer maize is of a little difference, but those for protective cultivation of tomato and watermelon are of great difference.