PHYTOTOXINS FROM PLANT-PATHOGENS AS POTENTIAL HERBICIDES

Plant pathogens remain a largely untapped reservoir of natural compoun ds with potential as herbicides or as herbicide leads. Many preliminar y studies have identified a variety of non-host-specific phytotoxins i solated from pathogenic bacteria and fungi that deserve further invest igation. Host-specific phytotoxins are less numerous and have sometime s been shown to have broader spectra when tested on a variety of plant s, including weeds, This may allow the application of these toxins or their analogs in weed management. The study of phytotoxins produced by weed pathogens is relatively new. This may be where the greatest chan ce of developing commercial herbicides lies. Because they are derived from weed-infesting pathogens, such phytotoxins may have more chance o f being toxic to weeds and less likelihood of damaging crops. However, much work still needs to be done, including isolation, purification, and host specificity testing, as well as production and safety studies . Since the traditional methods of herbicide discovery are becoming le ss productive, the study of microbially-derived herbicides could be a major source of new herbicides and herbicide templates in the future. More effort should be expended in this area of research in the future, despite the obstacles that exist.