Seed-borne Fungal Diseases of Onion, and their control

Abstract

Aspergillus niger, Botrytis aclada and Fusarium oxysporum f. sp. cepae are relevant seed-borne fungi of onion (Allium cepa L.) and are known as causal agents of black mould, neck rot and basal rot diseases, respectively. These pathogens can be transmitted from infected seeds to seedlings, sets or bulbs. They eventually kill the entire plant through degradation of the tissues. Different principles are suggested for their control. Botrytis squamosa, Cladosporium allii-cepae and Stemphylium vesicarium, which cause several lesion on the onion leaves, can also occur on seeds but they are not able to demonstrate disease transmission to the plant parts. The role of other seed-borne fungi (namely, Alternaria alternata, Aspergillus alutaceaus, A. flavus, Beauveria bassiana, Cladosporium cladosporioides, Colletotrichum dematium, Curvularia lunata, Drechslera australiensis, Humicola fuscoatra, Stemphylium botryosum, Trichoderma harzianum, T. pseudokoningii and Trichothecium roseum) on development of onion diseases is not known.KeywordsFusarium OxysporumTrichoderma HarzianumOnion BulbAllium CepaPectic EnzymeThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.