ABSTRACT
The use of pathogens as biocontrol agents for weed control is relatively new in comparison to their use in insect control. This chapter highlights recent in-depth reviews on biocontrol of weeds using plant pathogens have dealt with a number of ecological constraints. The greatest constraint to effective use of pathogens as biocontrol agents of weeds is the environment. The some components of the environment repeatedly identified as the most limiting are temperature and moisture. There has been considerable research on microorganisms in the phyllosphere, with much of the focus on the potential for biocontrol of plant pathogens. Regulations are one of the main constraints to the successful development and commercialization of pathogens as weed biocontrol agents. Bioherbicides can overcome many of the constraints on the classical use of pathogens for weed control. Constraints to development and successful use of plant pathogens as biocontrol agents of weeds are mainly ecological and regulatory.
