Efficacy of Trichoderma spp. as biological control agent of Sclerotium rolfsii Sacc.
2001
Cuevas, V.C. (Philippines Univ. Los Banos, 4031 College, Laguna (Philippines). Inst. of Biological Sciences) Sinohin, A.M. | Arro, E.A. Jr
The efficacy of a combination of two species of Trichoderma (T. parceramosum and T. pseudokoningii) in controlling the pathogenicity of Sclerotium rolfsii, which causes several crop diseases, was tested on seedbeds which had previously been abandoned due to severe rice seedling blight. Trichoderma was as effective as propamocarb hydrochloride in controlling pre-emergence damping-off of Brassica chinensis but only Trichoderma was effective in controlling post-emergence damping off and seeding blight in rice grown after B. chinensis. However, control by Trichoderma was slow. Efficacy was seen only after 6 intoductions of Trichoderma in the seedbeds grown to 3 successive crops of B. chinensis. Control of pathogenic activity as shown by percent seed germination and percent survival of seedlings in plots was most effective where Trichoderma was seeded twice (2 weeks and 1 week before seed sowing) with 30 g carrier rice bran pellets of mixed culture of the two species. The decrease in disease incidence was due to a decrease in percent viable sclerotial bodies after three successive croppings of B. chinensis. Application of the antagonist every cropping was effective in lowering the population of the pathogen's propagules, the sclerotia, and its effect was long-lasting
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