Betelvine (Piper betle L.) is the most important cash crop grown almost all over the state of West Bengal, India. The most important betelvine growing districts in West Bengal are Midnapore (East), Howrah, Hooghly, 24-Parganas (South) and Nadia. Besides the above districts, cultivation has now been extended to 24-Parganas (North), Birbhum, Bankura, West Dinajpur and Murshidabad districts too. It is affected by a large number of diseases, which reduces yield and quality of betelvine leaves. Bacterial leaf spot and stem rot disease caused by Xanthomonas axonopodis pv. betlicola and Pseudomonas betel respectively are gradually become important in West Bengal. Phoma piperis-betle is also prevalent in the state. When X.a. pv. betlicola and Ps. Betel jointly inoculated in same leaf, the size of the lesion become larger as compare to the lesion produced by individual bacterium. Simultaneous inoculation of X. a. pv. betlicola, Ps. betel and P. piperis-betle did not have pronounced effect in respect to lesion size in leaves. But inoculation of bacteria, 48 hours after inoculation of P. piperis-betle greatly increased lesion size.
