Trichoderma harzianum

About: Trichoderma harzianum is a research topic. Over the lifetime, 4731 publications have been published within this topic receiving 96796 citations.

Evaluation of fungal culture filtrate containing chitinase as a biocontrol agent against Helicoverpa armigera

Abstract: Aims: To evaluate the biocontrol efficacy of culture filtrate containing chitinase from Trichoderma harzianum against Heliothis. Methods and Results: T. harzianum was cultured by submerged fermentation using colloidal chitin as sole carbon source. The ability of the culture filtrate to hydrolyse colloidal chitin indicated the presence of chitinase as one of its components. Biocontrol assay on Heliothis showed that the culture filtrate is a potent antifeedant as it reduced the feeding rate and body weight of the larvae. It reduced the successful pupation and increased larval and pupal mortality in a dosage-dependent manner when applied topically. The highest mortalities (70%) were recorded for groups treated with 2000 U ml−1 chitinase activity. The percentage of adult emergence was zero for the highest chitinase concentration (2000 U ml−1) tried. Conclusions: The studies showed that the culture filtrate containing chitinase from T. harzianum is capable of negatively affecting the growth and metamorphosis of Heliothis larvae. Significance and Impact of the Study: In view of the need for safer and environmentally friendly pest management tools, the present study could help in the development of enzyme-based biopesticides against Heliothis.

In vitro interactions between the vesicular-arbuscular mycorrhizal fungus glomus mosseae and some saprophytic fungi isolated from organic substrates

Abstract: Six saprophytic fungi belonging to different genera and isolated from three organic substrates were tested under controlled in vitro conditions for their effect on the germination of Glomus mosseae (Nicol & Gerd) Gerd & Trappe resting spores and on the development of vesicular-arbuscular mycorrhizal fungal (VAMF) mycelium The development of G mosseae was stimulated by sterile water extracts from organic substrates and by the presence of Trichoderma spp isolated from these substrates Microbial inoculation did not affect the percentage of spore germination, which reached 90–95% after 26 days' incubation, but the germination rate was hastened and the development of VAM mycelium from germinated spores was enhanced by the presence of Trichoderma spp Stimulation caused by Trichoderma might be attributed to the production of volatile compounds more than to non-volatile compounds released to the growing media No hyphal contact between both types of fungi was necessary to detect stimulation in dual inoculation treatments The other saprophytes tested inhibited spore germination

Inhibition of aflatoxin B1 production of Aspergillus flavus, isolated from soybean seeds by certain natural plant products

Abstract: Aims: The inhibitory effect of cowdung fumes, Captan, leaf powder of Withania somnifera, Hyptis suaveolens, Eucalyptus citriodora, peel powder of Citrus sinensis, Citrus medica and Punica granatum, neem cake and pongamia cake and spore suspension of Trichoderma harzianum and Aspergillus niger on aflatoxin B1 production by toxigenic strain of Aspergillus flavus isolated from soybean seeds was investigated. Methods and Results: Soybean seed was treated with different natural products and fungicide captan and was inoculated with toxigenic strain of A. flavus and incubated for different periods. The results showed that all the treatments were effective in controlling aflatoxin B1 production. Captan, neem cake, spore suspension of T. harzianum, A. niger and combination of both reduced the level of aflatoxin B1 to a great extent. Leaf powder of W. somnifera, H. suaveolens, peel powder of C. sinensis, C. medica and pongamia cake also controlled the aflatoxin B1 production. Conclusions: All the natural product treatments applied were significantly effective in inhibiting aflatoxin B1 production on soybean seeds by A. flavus. Significance and Impact of the Study: These natural plant products may successfully replace chemical fungicides and provide an alternative method to protect soybean and other agricultural commodities from aflatoxin B1 production by A. flavus.