Survey and identification of soil-borne fungal pathogens causing seedling diseases on cotton

Cano, L.C.; Catedral, I.G.

Survey and identification of soil-borne fungal pathogens causing seedling diseases on cotton

1989

Cano, L.C. | Catedral, I.G. (Cotton Research and Development Inst., Batac, Ilocos Norte (Philippines))

The organism identified were Rhizoctonia solani Kuhn, Sclerotium rolfsii Sacc, Pythium sp., Phytophthora sp., Aspergillus sp., Fusarium spp., Penicillium sp., Rhizopus sp., Helminthosporium sp., Colletotrichum sp., Curvularia sp., Thielaviopsis sp. and Cladosporium sp. Of the 13 organisms identified, the most dominant was Aspergillus sp. followed by R. solani, Pythium sp., S. rolfsii and Phytophthora sp. Pathogenicity tests showed that R. solani, S. rolfsii, Pythium sp. and Phytophthora sp. were the pathogens that caused damping-off of cotton seedling. Fusarium spp. caused stunting. Poor seed germination and seed rotting were apparent on plants inoculated with Fusarium spp., Rhizopus sp. and Aspergillus sp. while Thielaviopsis sp. caused shriveled toproots. Results suggest that a chemical control program for cotton seedling diseases must be specifically effective against R. solani, S. rolfsii, Pythium sp. and Phytophthora sp. and that seed treatments should be adopted only in areas where these pathogens are present.

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