Cover Story
Minimize Plant Injury and Reduce Anthracnose Basal Rot in your Putting Green By Wakar Uddin, Ph.D.
B
asal rot anthracnose is a destructive disease of annual bluegrass (Poa annua L.) and creeping bentgrass (Agrostis stolonifera L.) in North America and western Europe. Anthracnose in turfgrass had been previously classified as senectopathic problem associated with advanced senescence of plant tissue where infection is usually initiated (1). However, incidence and severity of the disease in golf course putting greens have dramatically increased in recent years (2, 3). The reason for the increased problem in putting greens is unclear. It is likely that certain cultural practices and changes in pathogen population may have, at least in part, contributed to the problem. Two phases of the disease are commonly recognized – the foliar blight and the basal rot (5). The foliar blight phase develops
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Pennsylvania Turfgrass • Summer 2021
during warm periods in the summer, and the basal rot phase may occur at any time of the year depending on the geographic area. In close-cut annual bluegrass, small orange and yellow spots may appear in the winter or spring, and infection of crown results in yellowing followed by death of the plants. Infected plants later develop acervuli and melanized setae and profuse production of these structures may be found on crown and stem tissues or between the sheaths of the dying and deteriorating (Fig. 1). Nutritional deficiencies and environmental stresses are also important factors influencing anthracnose basal rot development. Turfgrass cultural practices that cause mechanical injury to plant tissue, particularly crown, stolon, and stem tissue, provide infection courts for the anthracnose pathogen for efficient
