Elisabeth Clover Artemis Kitchin, E. Lee Butler, Brandi C Merrick, & James P. Kerns
Abstract
Take-all root rot (TARR) is a disease caused by various related soil-borne fungi. It mostly develops on ultradwarf bermudagrass (UDB) putting greens, yet other warm-season grasses can develop the disease. Take-all root rot is the most common disease diagnosed on ultradwarf bermudagrass putting greens since 2016 according to the North Carolina State University (NCSU) Turfgrass Diagnostics Lab. Symptoms of TARR include white to off-color patches in varying sizes and necrosis of the roots and stolons. In order to determine relative resistance of ultradwarf bermudagrass cultivars to TARR, a greenhouse study was conducted in the greenhouse on the NCSU campus. Pots were arranged on a greenhouse bench and 400 cc of sterile play sand was added to each pot. Inoculum was prepared by placing two pathogens, G. graminis and G. graminicola,into sterile rye-grain amended with calcium carbonate for four weeks at room temperature.
Four ultradwarf bermudagrass cultivars, ‘Champion’, ‘Mini-verde’, ‘Tifeagle’, and ‘G-12’, were collected from local golf courses using a 3.5-cm-diameter probe. The plugs were cut to 2.5 cm in length and were washed for 30 seconds with water before being placed on top of 5 cc of the rye grain inoculum and top dressed with 10 cc of sand. A non-inoculated pot for each cultivar served as the control. The samples were then maintained in the greenhouse for four weeks and monitored for symptoms characteristic of TARR. Weekly ratings were taken based on overall turf quality as well as severity of disease symptoms.
The results of this study are still in progress and will be updated as they become available.
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