A influência do umedecimento das folhas sobre a abertura dos estômatos

Resumo

Experiments with Ficus Benjamina L, Luhea devaricata L., Michelia champaca L., Schinus therembintifolius Raddi., and Spathodea campanulata L., have shown that the moistening of leaves by dew, at night, causes a partial opening of the stomates. Ol the above mentioned plants only Luhea devaricata L. opens the stomates in nights without dew, but the opening is undoubtedly much more aceentuated in nights when dew is formed.

Also in the afternoon, when the stomates usually close or at least decrease their aperture due to a deficiency of water, the moistening of the leaves may alfect the condition of the stomates. A moistening for about 20 minutes proved enough to increase the opening of the stomates of Phaseolus vulgaris L., Luhea devaricata L. and Lycopersicum esculentum Mill. However, in Brassica oleracea var. acephala and Dianthus sp., plants covered with a waxy cuticle, no apparent change in the stomates could be detected after the leaves were moistened for the same period of time.