Horticultural Experiment Station, Chethalli, (I.I.H.R.), Coorg
Out of 178 citrus varieties and some of their relatives observed for their field resistance against powdery mildew disease, none was found completely resistant. All the members belonging to mandarins, tangarians and sweet orange group were found to be highly susceptible. Members belonging to Citrus aurantifolia, C. limon, C. medica, C. grandis, Poncirus trifoliata and its hybrids showed variable degree of susceptibility.
