Allelopathic effects of phenolic acids detected in buffalograss (Buchloe dactyloides) clippings on growth of annual bluegrass (Poa annua) and buffalograss seedlings

Fourteen different phenolic acids were detected in water extracts of buffalograss clippings. Six of the 14 phenolic acids, including p-coumaric acid, ferulic acid, gentisic acid, homoveratric acid, p-hydroxybenzoic acid, and vanillic acid, were examined for water and base extractable tissue concentration, and their effects on growth of seedlings of annual bluegrass (Pea annua) and buffalograss (Buchloe dactyloides). The tissue phenolic acid concentrations were found to be significantly different among the three buffalograss varieties examined. The variety 'Prairie' had a higher total tissue phenolic acid concentration than the concentrations detected in the varieties 'UCHL-1' and 'NE609', Seed germination was not affected by the six phenolic acids, but root growth of seedlings was severely inhibited. Seedling establishment was tested in buffalograss turf plots. No annual bluegrass became established in the buffalograss turf, and only 1%, of buffalograss seedlings became established. The allelopathic effects of the phenolic acids may be, at least partly, responsible for prevention of establishment of new plants in the sward. The allelopathic effects of these phenolic acids seem not to be species specific, but they act like a broad-spectrum preemergence herbicide that affects seedling establishment while not affecting established turfgrass This character may exist in other turfgrass species, and it is a potentially useful trait for turfgrass breeding. (C) 1998 Elsevier Science B.V. All rights reserved.