03-08-2013, 04:19 PM
French Bean Diseases and Their Management
ABSTRACT
French bean (Phaseolus vulgaris L.) is one of the most important leguminous vegetable crops, grown throughout the country for its green pods as well as dry beans (rajmah). In India, the crop is largely and traditionally grown in hilly tracts having mild climate with humid environmental conditions. Recently farmers and consumers have shown interest in growing pencil type of bean cultivars which suit to vegetable type. Such cultivars are fibreless, meaty type and tender which brings lucrative returns to the farmers. During cultivation, this crop is severely infected with several diseases of fungal bacterial and viral nature which causes significant yield reductions besides impairing the quality of the produce. Among various diseases, root rot and web blight (Rhizoctonia solani), anthracnose (Colletotrichum lindemuthianum), angular leaf spot (Phaeoisariopsis griseola), bean rust (Uromyces appendiculatus), common blight (Xanthomonas axonopodis pv. phaseoli) and bean common mosaic are important. Most of the diseases are seed borne and require moderate temperature (20-25o C) and high relative humidity i.e. >80 per cent. These diseases can be kept in check by integrating all the available disease management methods like use of healthy seed, seed treatment with carbendazim (0.2%), amend field soil with sarson cake at least 15 days before sowing, use yellow sticky traps and with the initiation of the disease spray the crop with the combination of mancozeb (0.25%) and carbendazim (0.1%) in case of web blight, anthracnose and angular leaf spot and repeat at 10-12 days interval whereas in case of rust spray the crop with hexaconazole (0.1%) followed by sprays of combination of mancozeb(0.25%) and hexaconazole (0.05%). Common blight can be kept in check with the seed treatment with Streptocycline (0.01%) followed by sprays of Streptocycline (0.01%) or copper oxychloride (0.25%). Common mosaic is reduced by using resistant cv. like Contender and use of neem oil (0.3-0.5%) sprays.