First record of occurrence and distribution of bacterial canker of capsicum under protected cultivation in Himachal Pradesh

摘要

Capsicum (Capsicum annuuin L.) was found to be attacked by a disease in Himachal Pradesh characterised initially on leaves as chlorosis, reduction of size and cupping of leaflets resulting into wilting of the leaves and shoots. The leaves wilted and curled but did not fall off. The wilt developed gradually from one leaflet to the next and destroyed much of the foliage, however the most conspicuous symptoms consisted of proliferation of stems.On stems, light coloured streaks appeared usually at the joint of petioles and branches. Later cracks developed in the streaks and formed the cankers. Finally, the stem completely turned necrotic and died. Survey conducted at 24 locations of four districts of the H.P. state revealed the variation of disease severity from 8.50 to 29.36 per cent causing around 20.06 to 74.91 per cent yield losses at different locations. Based upon microscopic bacterial streaming from the lesions, positive Gram staining, morphological and cultural assays, the pathogen was identified tentatively as Clavibacter sp. The pathogenicity of the isolated bacterium was also proved and the disease was identified as bacterial canker. This is the first record of the disease on bell pepper from Himachal Pradesh.