In this paper, mathematical models are presented to study the thermal behavior of crops (cabbage and peas) for open sun drying (natural convection) and inside the greenhouse under both natural and forced convection. The predictions of crop temperature, greenhouse room air temperature and rate of moisture evaporation (crop mass during drying) have been computed in Matlab software on the basis of solar intensity and ambient temperature. The models have been experimentally validated. The predicted crop temperature and crop mass during drying showed fair agreement with experimental values within the root mean square of percent error of 2.98 and 16.55, respectively. (C) 2004 Elsevier Ltd. All rights reserved.