Fonctionnement des stomates de Cocotier (<i>Cocos nucifera</i>) au champ

Abstract

The behavior of coconut (Cocos nucifera L.) stomata was studied under field conditions in adult plants. Hourly determination of relative stomatal opening and of stomatal conductance values revealed that coconut stomata were opened maximally between 0800 and 1600; by the end of this period, the stomata closed rapidly as solar radiation decreased. Changes in temperature and relative humidity of the air did not affect stomatal behavior. The maximum relative stomatal opening occurred at midday, when the water potential of the leaf is at its lowest point, showing that stomatal behavior depends mostly on solar radiation and does not control water loss efficiently under conditions of water stress.