Olpidium brassicae and Polymyxa graminis in Roots of Creeping Bent in Golf Putting Greens

Abstract

During an investigation to determine the occurrence of plant-parasitic nematodes associated with creeping bent (Agrostis palustris Huds.) in golf putting greens (9) microscopic examination of the roots revealed the presence of numerous cystosori of Polymyxa graminis Led. and resting spores of Olpidium brassicae (Wor.) Dang. Examination of other samples obtained from a putting green on the Harrison Park Golf Course, Danville, Illinois, in September revealed that the roots of 89 percent of the plants examined were infected with P. graminis. Stellate resting spores of 0. brassicae were present in the roots of all plants. The high incidence of these obligate parasites in adventitious roots, both primary and lateral, suggested that they might be instrumental in causing the annual killing of most of the root system of creeping bent in putting greens during midsummer in the midwest. Consequently, studies were begun to determine whether these fungi occurred commonly in Illinois putting greens, and if they were causing significant damage.