Subtropical Modern Greenhouse Cucumber Canopy Transpiration Under Summer Climate Condition  

作　　者：LUO Wei-hong, WANG Xiao-han, DING Wei-min, CHEN Yu-qing and DAI Jian-feng(Key Laboratory of Crop Growth Regulation , Ministry of Agriculture/Nanjing Agricultural University ,Nanjing 210095, P.R.China) 

出　　处：《Agricultural Sciences in China》2002年第11期1260-1265,共6页中国农业科学（英文版）

基　　金：the National Natural Science Foundation of China(60073028); the National“863”High-Tech Program(2001AA-247023)

摘　　要：Greenhouse canopy transpiration not only has effects on greenhouse air temperature and humidity, but also is important for determining the set-point of fertigation. In this study, Penman-Monteith equation was used to calculate the greenhouse cucumber canopy transpiration under summer climate condition. The effects of greenhouse environmental factors on canopy transpiration were analyzed based on the measurements of greenhouse microclimate factors and canopy transpiration. The results showed that Penman-Monteith equation was reliable and robust in estimating greenhouse cucumber canopy transpiration under summer climate condition. Greenhouse cucumber canopy transpiration rate increased linearly with the increase of net radiation and water vapor pressure deficit (VPD) above the canopy. But the maximum value of the canopy transpiration rate occurred at the same time as that of VPD whereas about two hours later than that of net radiation. Based on the results, it was concluded that in addition to radiation, air humidity should also be considered when determine the set-point of fertigation.Greenhouse canopy transpiration not only has effects on greenhouse air temperature and humidity, but also is important for determining the set-point of fertigation. In this study, Penman-Monteith equation was used to calculate the greenhouse cucumber canopy transpiration under summer climate condition. The effects of greenhouse environmental factors on canopy transpiration were analyzed based on the measurements of greenhouse microclimate factors and canopy transpiration. The results showed that Penman-Monteith equation was reliable and robust in estimating greenhouse cucumber canopy transpiration under summer climate condition. Greenhouse cucumber canopy transpiration rate increased linearly with the increase of net radiation and water vapor pressure deficit (VPD) above the canopy. But the maximum value of the canopy transpiration rate occurred at the same time as that of VPD whereas about two hours later than that of net radiation. Based on the results, it was concluded that in addition to radiation, air humidity should also be considered when determine the set-point of fertigation.

关 键 词：CUCUMBER GREENHOUSE Transpiration rate 

分 类 号：S642.2[农业科学—蔬菜学]