Submitted to: Phytopathology
Publication Type: Abstract Only
Publication Acceptance Date: April 30, 2002
Publication Date: June 1, 2002
Citation: Hanson, L.E. 2002. Biological control of sugar beet damping-off with trichoderma spp.. Phytopathology. Technical Abstract: Biological control of damping-off in sugar beet seedlings with Trichoderma species. Isolates of Trichoderma virens and other Trichoderma species are effective biocontrol agents for diseases of several crops. Control of damping-off caused by Rhizoctonia solani has been observed in a number of crop species. To test for biocontrol activity on sugar beet, Trichoderma strains were grown in 5% ground wheat bran and 1% ground peat moss. The preparation was air dried and applied to seed with a latex sticker. Seeds were planted in greenhouse potting mix with either sterile vermiculite or R. solani grown on sterile barley and mixed with vermiculite. The survival of sugar beet (FC403) seedlings under severe Rhizoctonia pressure was compared for different Trichoderma isolates in the greenhouse at 7, 14, and 21 days. Seedling roots were collected, washed and plated to determine fungal colonization. All of the Trichoderma isolates colonized sugar beet radicles and young roots well. Some fungal isolates significantly improved seedling emergence and survival in greenhouse tests. There was no significant correlation between in vitro antibiosis against R. solani and biological control activity. However, biocontrol-effective strains induce a higher level of peroxidase activity in seedling roots grown in sterile glass dishes than do biocontrol-ineffective strains.