Permanence of Free Water on Coffee Leaves

Abstract

Summary: The presence of free water on both surfaces of the leaves of shaded and unshaded coffee trees was evaluated at Cenicafé, Colombia. Rainfall was the main source of humidity and dew was not registered during the experiment. Five mm of rain caused canopy saturation and water began to reach the underside of the leaves. The period of wetness lasted 9.7 hours on average and no significant moisture differences were found between leaves on east or west facing branches, at different levels within the tree, or externally or internally positioned on the branches, either for exposed or shaded trees. Between 1700 and 0500 h (local time), a close relation was found between the time of rain initiation and the duration of the period of wetness. Leaves dried out at approximately 1000 h.