Diseases of rattan in nurseries, plantations and natural stands in Kerala, India

A disease survey in rattan nurseries, plantations and natural stands in Kerala State, India, revealed that Calamus dransfieldii, C. gamblei, C. hookerianus, C. pseudotenuis, C. rotang, C. thwaitesii, C. travancoricus and C. vattayila are susceptible to various fungal pathogens in different growth phases. In nurseries, seedlings are affected with diseases caused by Bipolaris ellisii, Colletotrichum gloeosporioides, Corynespora cassiicola, Fusarium longipes, Guignardia calami, Sclerotium rolfsii and Rhizoctonia solani. Of these, seedling blight caused by Guignardia calami and seedling collar rot caused by Fusarium longipes are the most important diseases. In plantations and natural stands, rattans are affected by various foliage pathogens, such as Bipolaris ellisii, Colletotrichum crassipes, Colletotrichum gloeosporioides, Glomerella cingulata, Pestalotiopsis theae, Phomopsis palmicola, Phyllachora calamigena and Sphaerodothis. Among these, Colletotrichum infection on unopened spear (frond) and Sphaerodothis foliage blight caused severe damage to young as well as mature plants. Stem rot and staining, caused by Pellicularia filamentosa and Botryodiplodia theobromae, respectively, are the other important diseases. Nursery diseases can be effectively controlled by application of fungicides, viz., carboxin, mancozeb, carbendazim by seed dressing, soil drenching or by foliar spraying.