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ARS Home » Research » Publications at this Location » Publication #93354
Title: BIOCONTROL OF SELECTED SOILBORNE DISEASES OF TOMATO AND PEPPER PLANTS.

Author
item MAO, WEILI - T.J. ENTERPRISES, SD
item Lewis, Jack
item Lumsden, Robert
item HEBBAR, PRAKASH - PENN STATE UNIV, PA

Submitted to: Elsevier
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/7/1998
Publication Date: N/A
Citation: N/A

Interpretive Summary: Biocontrol of pathogens that cause plant diseases is a recognized and acceptable alternative to the use of chemical fungicides that pollute the environment and chemical fumigants such as methyl bromide that destroy the protective ozone layer. This report demonstrates the application of a biocontrol fungus Gliocladium (Gl-3) and a biocontrol bacterium Burkholderia (Bc-F), individually and together, to seeds of tomato and pepper varieties to control seedling damping-off, root rot, and blight caused by a combination of soil-inhabiting plant pathogenic fungi. The efficacy, which was observed in both greenhouse and field trials, was enhanced by the supplemental application of a liquid drench containing Gl-3 and Bc-F. In addition to disease control, the biocontrol agents as seed treatments and drenches also increased plant height and weight and crop yield in the field. Of major importance was the general superiority of using Gl-3 + Bc-F together on seed and in a drench rather than each microb alone. The research benefits the health and quality of the environment and our food sources. It also demonstrates the feasible use of biocontrol in place of chemicals and suggests the implementation of the technology by industry.

Technical Abstract: Biocontrol of soilborne diseases of tomato caused by Rhizoctonia solani and Pythium ultimum alone or in combination with Sclerotium rolfsii and Fusarium oxysporum f. sp. lycopersici were studied in the greenhouse and field. Soilborne diseases of pepper caused by the first three pathogens were also studied alone or in combination with Phytophthora capsici. Tomato and pepper seeds were treated with biomass of Gliocladium virens (Gl-3) and Burkholderia cepacia (Bc-F), individually and in combination, and planted in pathogen-infested soilless mix. Seedling stands for tomato from treated seeds were comparable to that in noninfested soilless mix. Although seed treatments with individual biocontrol agents also effectively reduced damping-off in peppers, only the Gl-3 + Bc-F treatment resulted in stands similar to the noninfested control. When healthy seedlings of both crops were transplanted into pathogen-infested soil/soilless mix in the greenhouse, and supplementary root drenches of suspensions of Gl-3, Bc-F, and Gl-3 + Bc-F were applied, plant fresh weight was significantly greater and disease severity (DSI) was significantly less than for infested controls. When transplants were set out into infested field plots, the combined Gl-3 + Bc-F application resulted in greater fresh weight and lower DSI for pepper, and greater fruit yield for tomato than those obtained with either Gl-3 or Bc-F alone.