Survey and identification of soil-borne fungal pathogens causing seedling diseases on cotton in Mindanao [Philippines]
1989
Cano, L.C. | Catedral, I.G. (Cotton Research and Development Inst., Polomolok, South Cotabato (Philippines))
The study was conducted to survey and identify soil-borne fungal pathogens causing seedling diseases on cotton. The organisms isolated from the soil samples were Rhizoctonia solani Kuhn, Sclerotium rolfsii Sacc., Pythium 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. Other species were considered not important because of their scarcity in the soil. Pathogenicity test showed that R. solani, S. rolfsii, Pythium sp., and Phytophthora sp. were the major pathogens causing damping-off diseases on cotton. Plants inoculated with Fusarium spp. were stunted. Poor seed germination and seed rotting were also noted. The two host reactions were also apparent on plants inoculated with Rhizopus and Aspergillus. Thielaviopsis sp. caused shriveled taproots. Species of Colletotrichum, Cladosporium, Penicillium, Helminthosporium and Curvularia were not pathogenic to cotton seedlings.
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