Chowdappa, P.Balasimha, D.2014-07-082014-07-082007-02Indian Phytopathology 1992 v-45 p-312-315http://hdl.handle.net/123456789/3820Gas exchange rates in the apparently healthy and yellow leaf diseased (YLD) arecanut palms were studied. Net photosynthetic rate (A) was significantly reduced in the leaves of diseased palms compared to apparently healthy palms, while internal CO2 concentration (C.) increased. Stomatal conductance (g1) and transpiration rate (E) decreased significantly in the diseased palms. Significant reductions in A/g and A/C ratios were also observed in diseased palms. Similar trend was observed at different times of the day (8.00 to 16.00 h). The results indicate that mesophyll factors were more affected than the stomatal factors in the leaves of diseased palms. Hence, A was reduced more that. E leading to low A/E ratio.enArecanut palmsyellow leaf diseaseinhibitionphotosynthesisArticle