Biocontrol of Botrytis Cinerea on Greenhouse-Grown Ornamentals

Floral production in the United States has an estimated value of over $11 billion. Geraniums and roses together constitute a significant portion of this value. Grey mold, caused by Botrytis cinerea Pers.:Fr. is prevalent and often devastating under the cool, moist conditions which are common in greenhouses where the crops are produced. The fungus attacks all of the above ground portions of the plants, but foliar and floral blights are the primary causes of economic loss, especially for roses used in cut flower production. Currently registered chemical fungcides used to control this disease are relatively ineffective due to resistance developed by Botrytis against the chemicals. Additionally, the heavy use of chemical pesticides causes health concerns to applicators, greenhouse workers and the consumer public which purchases the flowers. The proposed Phase I research would evaluate the use of multiple microbial pest control agents (MPCAs) to combat this disease. Combinations of beneficial fungi, bacteria and yeast will be evaluated in vitro and in vivo to evaluate their ability to prevent grey mold and to overcome fungicide resistant strains of Botrytis. Phase II would test these organisms under commercial greenhouse conditions.