- Certain turfgrass species exhibit the ability to produce large quantities of root exudates which contain bioherbicides or natural products which are highly effective weed suppressive agents. After many years of field and laboratory research, we have identified specific cultivars of fine leaf fescue which are highly allelopathic or weed suppressive. We have developed recommendations for landscape managers as to which cultivars to select, planting rates and maintenance requirements for optimal performance. We have identified a novel allelochemical which is a potent inhibitor of seedling growth in higher plant species, and identified cultivars and species of fescue which produce this inhibitor. We have obtained an international patent for m-tyrosine, the novel inhibitor associated with weed suppression in fescue species. We have investigated the mode of action and soil persistence of this compound and fescue root exudates in general. We are now working to investigate the potential to select and breed turfgrasses with greater inherent weed suppressive activity as well as develop m-tyrosine or related chemistry as novel soil-applied organic herbicides.