Abstract: Disclosed are novel methodologies for virulence enhancement of fungal and bacterial pathogens for biological control of target plants. Described is a selection process for phytopathogenic microorganisms that excrete selected amino acids. Pathogenicity studies demonstrate that these amino acid-excreting plant pathogens show greater virulence against target plants than do corresponding wild type strains. Host range evaluations of these mutants did not reveal any increase of virulence towards non-target plants. This novel approach to enhancement of microbial herbicides can be used across a broad spectrum of microbial groups to improve the efficacy of bio-control. Also disclosed is the use of selected mutants of plant pathogenic microorganisms that overproduce one or more inhibitory amino acids to enhance control of target plants.

Abstract: We herein reveal a methodology for the dispersal of bioherbicides intended for control of target plants. The methodology can be used for dispersal of various bioactive agents in addition to bioherbicides, for instance to disseminate bioassistive agents such as Rhizobium cultures. We describe a process for selection of live seed carriers, bioherbicide coating of selected seed, and aerial dispersion of live seed formulation. Aerial dispersion of bioherbicide with live seed carriers demonstrates a vast improvement in bioherbicide establishment, including penetration throughout the soil profile and into the target root zone. In addition, the active concentration of the bioherbicide is increased within the root zone of the carrier plant. This novel approach for dispersal of bioherbicides can be used across a wide spectrum of target plants and should greatly improve the efficacy of bioherbicides.