Maximum evapotranspiration of sweet pepper in plastic greenhouse as a function of solar radiation, temperature, relative humidity and water vapor pressure deficit of the air

摘要

> size="2" face="Verdana, Arial, Helvetica, sans-serif">An experiment was carried out to study the relationship between sweet pepper maximum evapotranspiration (ETm) per unit leaf area index (ETmf) and incident solar radiation (Rg_e) and net radiation (Rn_e) outside greenhouse, and with air temperature (t_am), air relative humidity (URm) and water vapor pressure deficit (D) inside a greenhouse. ETm was measured by lysimeters. Temperature and relative humidity were registered whereas Rg_e and Rn_e were estimated. The Rn_e was the variable with laRg_est effect on ETmf determination, followed by D and URm. The air temperature at 15:00 and the daily maximum temperature were variables of laRg_er association with ETmf among the variables with punctual time observations. Rg_e improved its relationship with ETmf when was analyzed with different t_am ranges. The results confirmed Rn_e and D as the meteorological variables of highest relationship with evapotranspiration in plastic greenhouse grown crops in autumn. However, the degree of adjustment of this relationship for sweet pepper is different from those reported for other crops.