Studies on Eco friendly Approaches for the Integrated Management of Fungal diseases of Onion Allium cepa L

Abstract

Onion (Allium cepa L.) is herbaceous biennial plant belongs to family Amaryllidaceae. The onion also known as the bulb onion or common onion is one of the most important vegetable crops in India newlineThe major restriction that limit production due to basal rot (Fusarium oxysporum f.sp.cepae; Pythium sp.; Sclerotium cepivorum and S. cepivorum and Colletotrichum sp.), purple blotch (Alternaria porri), stemphylium blight (Stemphylium vesicarium), basal rot (Fusarium oxysporum f.sp. cepae), downy mildew (Perenospora destructor), smut (Urocystis cepulae), black mold (Aspergillus niger), bacterial brown rot (Pseudomonas aeruginosa), white rot (Sclerotium cepivorum), neck rot (Botrytis allii) and onion smudge (Colletotrichum circinans). The present investigations include the objectives such as survey of onion fungal disease, physico- chemical parameters of rhizospheric soil and infected onion. population dynamics of mycoflora in infected rhizospheric soil of onion, isolation, identification and pathogencity of the pathogens, sensitivity of pathogens to different fungicides(MIC), study of enzymes and toxins of the pathogens and biopesticidal management strategy of the pathogens. newlineThe onion plants caused by black mold (Aspergillus niger van Tieghem), basal rot (Fusarium oxysporum f. sp. cepae Schlecht), neck rot (Botrytis allii Munn) and white rot (Sclerotium cepivorum Berk.) were found severe and common during survey in study sites.All four pathogens infected rhizosphere soils was collected from study sites and sixteen physico- chemical parameters analysed. It founds alkaline pH but EC, P and K contents were found maximum in all infected rhizospheric soil but OC was found minimum amount in S. cepivorum infected soil as compared to standard range. Macro nutrients like Nitrogen (N) found more in infected by F. oxysporum followed by A.niger , Phosphorus and Potassium (K) found maximum amount but the secondary macro nutrients like Calcium (Ca) was found minimum in all study sites. Magnesium (Mg) were found more amount in A. niger (2