Transpiration rate is influenced by factors such as temperature, humidity, surface area, respiration rate, and air movement. The relative humidity of the ambient atmosphere has a considerable effect on water loss of fresh produce during storage. Burton and Noble (1993) found that weight losses from mushrooms stored in open punnets at either 5 °C (73% RH) or 18 °C (90% RH) were linear, averaged 4% per day at 5 °C and 6% per day at 18 °C. Shirazi and Cameron (1992) found that the rate of weight loss of individual tomatoes dropped rapidly by 50% when the RH was increased from 52% to 85% at 20 °C. Patel, Pai, and Sastry (1988) calculated transpiration coefficients for mushrooms using a model reported by Sastry and Buffington (1983) for mass transfer from a respiring, spherical skinless product. They found that the transpiration coefficient decreased with increasing water vapor pressure difference.