STP1183

    Use of Pregelatinized Starch and Other Polysaccharides for Improved Storage and Efficacy of Biocontrol Agents

    Published: Jan 1993


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    Abstract

    Nutritional and environmental factors present both during inoculum production and the infection or colonization process ultimately influence effectiveness of biocontrol agents. Conidial efficacy of Colletotrichum truncatum NRRL 13737 for control of Sesbania exaltata was evaluated after providing amendments to spores which had been produced in media with differing carbon to nitrogen (C:N) ratios. Conidia produced in a medium with a C:N ratio of 10:1 incited more severe disease in seedling assays than spores produced in 30:1 medium, though amending with pregelatinized starch increased the efficacy of 30:1 spores to levels comparable to 10:1 spores without amendment. Casamino acids increased the severity of disease incited by 10:1 spores but generally did not influence 30:1 spore efficacy. Cell viability after storage, seed germination, and disease suppression were evaluated after treating wheat seed with various formulations of Pseudomonas fluorescens 2-79 (NRRL B-15132) cells of different age for control of take-all (caused by Gaeumannomyces graminis var. tritici). Viability, germination, and disease suppression declined over 6 months storage. Effects of cell age (24, 48, and 96 h) were not consistent. Cells resuspended in methylcellulose-water (MW) survived better on wheat seed than cells resuspended in methylcellulose-broth (MB) and MW treated seed retained a higher germination rate. However, disease suppression was best on MB treated seed.

    Keywords:

    biocontrol, bioherbicide, fungi, bacteria, weeds, plant disease formulations, storage, starch


    Author Information:

    Bothast, RJ
    microbiologistsPlant PathologistChemical Engineer, Fermentation Biochemistry Research Unit, National Center for Agricultural Utilization Research, USDA, Agricultural Research Service, Peoria, Illinois

    Schisler, DA
    microbiologistsPlant PathologistChemical Engineer, Fermentation Biochemistry Research Unit, National Center for Agricultural Utilization Research, USDA, Agricultural Research Service, Peoria, Illinois

    Jackson, MA
    microbiologistsPlant PathologistChemical Engineer, Fermentation Biochemistry Research Unit, National Center for Agricultural Utilization Research, USDA, Agricultural Research Service, Peoria, Illinois

    VanCauwenberge, JE
    microbiologistsPlant PathologistChemical Engineer, Fermentation Biochemistry Research Unit, National Center for Agricultural Utilization Research, USDA, Agricultural Research Service, Peoria, Illinois

    Slininger, PJ
    microbiologistsPlant PathologistChemical Engineer, Fermentation Biochemistry Research Unit, National Center for Agricultural Utilization Research, USDA, Agricultural Research Service, Peoria, Illinois


    Paper ID: STP25123S

    Committee/Subcommittee: E35.22

    DOI: 10.1520/STP25123S


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