International Journal of Applied Agricultural Research

The survival of Exobasidium vexans during off season (January to May) was investigated. Four tea fields under varying microclimate were selected and disease incidence was monitored for four consecutive years. During the months of April and May, the disease totally disappeared in all the areas except in tea fields near ravine where it was present on young succulent shoots developing on side branches arising below the canopy. Microclimatic conditions such as higher relative humidity, lesser temperature and longer duration of surface wetness in the ravine favoured the disease throughout the year. Basidiospores of the pathogen was present in the atmosphere throughout off season and it was very low (<10 spores/m³ air) during the months of April and May. During this period, pathogen produced thick walled spores which failed to germinate in vitro indicating specific nutrient/environmental requirement for its germination. These spores may help in over wintering of the pathogen.