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ARS Home » Southeast Area » Fort Pierce, Florida » U.S. Horticultural Research Laboratory » Subtropical Plant Pathology Research » Research » Publications at this Location » Publication #158832
Title: SUPPRESSION OF COGONGRASS WITH A BIOHERBICIDAL FUNGUS AND PLANT COMPETITION

Author
item Ables, Camilla
item CHARUDATTAN, R. - UNIV. OF FLORIDA
item SHILLING, D. G. - UNIV. OF FLORIDA

Submitted to: Weed Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/9/2003
Publication Date: 1/1/2004
Citation: Yandoc, C.B., Charudattan, R., Shilling, D. 2004. Suppression of cogongrass (Imperata cylindrica) with bioherbicidal fungus and plant competition. Weed Science. 52:649-654.

Interpretive Summary: The strategy of using a biological control agent (Bipolaris sacchari) mixed with oil emulsion to selectively suppress cogongrass planted with bahiagrass was tested in the greenhouse. Application of the fungus-oil emulsion mixture caused greater damage on cogongrass than bahiagrass; cogongrass fresh weight, number of rhizomes produced, and plant height of cogongrass were reduced. Bahiagrass exhibited phytotoxic damage but was able to recover after a few weeks. Results also indicated that the application of the fungus-oil emulsion mixture may or may not result in increased bahiagrass biomass but cogongrass competitive ability was reduced.

Technical Abstract: The possibility of using the fungus Bipolaris sacchari as a bioherbicide to suppress cogongrass and to allow for the establishment of bahiagrass (Paspalum notatum) in cogongrass-bahiagrass mixed plantings was investigated under greenhouse conditions. The bioherbicide was prepared by mixing B. sacchari spore suspension containing 105 spores ml-1 with an oil emulsion composed of 16% horticultural oil + 10% light mineral oil, and 74% sterile water. The application of the bioherbicide caused severe foliar blight in cogongrass and some degree of phytotoxic damage on bahiagrass. In the first experiment, bioherbicide application resulted in significant cogongrass biomass reduction; however, an increase or decrease in bahiagrass biomass was not observed. The second experiment showed that aside from a 64% biomass reduction, application of the bioherbicide also resulted in 74% reduction in the number of rhizomes produced by cogongrass and 47% reduction in cogongrass plant height. The latter experiment also showed an increase in bahiagrass biomass in the presence of cogongrass when the bioherbicide was applied. This study indicated the potential of using a combination of bioherbicide application and plant competition from a desirable grass as a strategy for the integrated management of cogongrass.