Dayan, E., A.R.O., Besor Exp. Stat., Mobile Post Negev 4, 85400, Israel
Fuchs, M., A.R.O., Soil and Water Inst., P.O. Box 6, Bet Dagan, 50250, Israel
Plaut, Z., Southern R and D, Besor Exp. Stat., Mobile Post Negev 4, 85400, Israel
Presnov, E., A.R.O., Besor Exp. Stat., Mobile Post Negev 4, 85400, Israel
Grava, A., A.R.O., Soil and Water Inst., P.O. Box 6, Bet Dagan, 50250, Israel
Matan, E., Southern R and D, Besor Exp. Stat., Mobile Post Negev 4, 85400, Israel
Solphoy, A., Southern R and D, Besor Exp. Stat., Mobile Post Negev 4, 85400, Israel
Mugira, U., Extension Service, Ministry of Agriculture, P.O. Box 6, Bet Dagan, 50250, Israel
Pines, N., Extension Service, Ministry of Agriculture, P.O. Box 6, Bet Dagan, 50250, Israel

Rose flowers produced in greenhouses during the Israeli summer are of poor quality, due presumably to the high temperatures and low air humidity obtained with natural ventilation (NV). Several variants of commercial cooling methods were tested to reduce the duration of high temperature exposure in greenhouses. The treatments included were: NV (reference), with and without shading, and forced ventilation with and without an evaporative pad. Modified concepts issued from a steady state energy balance model set a frame for analyzing the course of action of the treatments. The cooling treatments hardly reduced average temperatures of air, plant, or flower. Due to morphology, the plant absorbed most of the radiant energy entering the greenhouse, and most of it was removed as latent heat. In comparison to NV, the treatments produced limited additional cooling because each of them reduced the transpiration rates.