Eco Friendly Management of Anthracnose of Black Gram

The black gram [Vigna mungo (L.) Hepper] commonly known as urdbean, is an annual semi erect to spreading herb belonging to the family Leguminosae. Black gram is locally known as Urad dal (Hindi), Minumulu (Telgu), Ulundu Paruppu (Tamil), Uddina bele (Kannada), Masakalai dala (Bengali), Biri dali (Oriya), Adad dal (Gujrat), Kali dal, Udid (Marathi) in India. It has been growing in India, Pakistan, Bangladesh, Sri Lanka, Thailand, Vietnam, Indonesia, South China and Malaysia since ancient times. India is said to be the origin of black gram (Piper and Morse, 1914). India as the primary Urd bean origin centre with Central Asia as a secondary location (Vavilov, 1926). Black gram has high nutritional value containing, fat (1.4%), protein (24%), carbohydrate (59.6%), calcium (154 mg), phosphorus (385 mg), iron (9.1 mg), thiamine (0.4 mg), riboflavin (0.37 mg), niacin (2 mg) and beta carotene (38 mg) per 100 gseeds (Gopalan et al. 1971). It is a nutritive fodder for animals, especially milch animals. The leaves and stems are the most common sources of fodder, but seeds, pods and pod husks are also used. Black gram crop is itself a mini-fertilizer factory, as it has unique characteristics of maintaining and restoring soil fertility through fixing atmospheric nitrogen through symbiotic association with Rhizobium bacteria, which are present in the root nodules. Black gram can fix atmospheric nitrogen to the tune of 30 kg nitrogen per hectare per year. Black gram can be used as green manure and a cover crop. The crop is suitable for intercropping with different crops such as sorghum, cotton, pearl millet, green gram, maize, groundnut and soybean for increasing production and maintaining soil fertility (Parashar, 2006). India is the world'sleading producer of black gram, accounting for more than 70 percent of global output, followed by Myanmar and Pakistan (Anon., 2020). In India, the black gram area increased by 386 percent in Kharif 2020-21, from 1.88 lakh ha in 2019-20 to 8.77 lakh ha in 2020-21. Madhya Pradesh (4.45 lakh ha), Maharashtra (1.79 lakh ha), Rajasthan (0.71 lakh ha), Karnataka (0.58 lakh ha), Telangana (0.11 lakh ha) and Andhra Pradesh (0.04 lakh ha) are the major kharif growing states (Anon., 2020). In Gujarat, black gram is primarily grown in the kharif season in the Kutch, Banaskantha, Saurashtra, Mahesana and Panchmahal districts, with adequate but erratic rainfall. During the summer, however, it is grown extensively in the districts of Kheda, Vadodara and Panchmahal (Anon., 2020). Biotic and Abiotic stresses cause significant yield reduction in black gram. Among the various fungal diseases, the occurrence of anthracnose disease in black gram is commonly observed inmost of the cultivated areas. Anthracnose continues to be one of the major constraints in black gram cultivation caused by Colletotrichum spp. is world'smost important seed and soil-borne disease. At least four species of Colletotrichum have been found associated with green gram and black gram causing anthracnose indifferent parts of the world (Saxena and Sinha, 1977). It has been reported to possess high pathogenic variability and more than 100 races of C. lindemuthianum have been identified worldwide (Sharma et al., 2007). Anthracnose pathogen (Colletotrichum spp.) attacks all aerial parts of plants at all stages of development. Symptoms are black, circular, sunken spots with a dark centre and bright red-orange margins appear on leaves and pods. The cotyledons of seedlings show dark brown to black sunken spots, which may bear pink spore masses of the fungus in wet weather and become blighted due to infection shortly after seed germination. In the event of a severe infection, the affected parts, particularly the leaves, wither. The pathogen perennates on infected seeds and in the soil on diseased plant debris. The secondary infection takes place through airborne conidia. The disease is most common in areas with cool and wet weather and it can result in a yield loss of up to cent per cent. Various researchers have estimated yield losses due to anthracnose between 24 to 67 percent (Deeksha and Tripathi, 2002), 18.2 to 86.6 percent (Laxman, 2006) and 21.36 to 60.07 percent (Kulkarni, 2009).