An overview of the experiment showing the various fertility treatments and the presence of Microdochium nivale.
Microdochium nivale is a disease of major concern in cool, humid regions where turfgrass is grown. Presently, the only methods to ensure control of this disease are through the use of synthetic fungicides. v The objective of this fertility trial is to evaluate the effects of different winter fertility combinations in association with simulated golf course traffic in order to assess their potential as alternative management options for Microdochium nivale on Poa annua putting greens.
A field trial at Oregon State University, Corvallis, Ore., was initiated in September 2013 on a green that was built by placing 6 inches of a sand that met USGA guidelines on a soil subgrade with no drainage. All possible combinations of three rates of nitrogen in the form of urea 0, 0.1 and 0.2 lb. per 1,000 ft2 and five rates of iron sulfate heptahydrate 0, 0.25, 0.5, 1.0 and 2.0 lbs. per 1,000 ft2 are applied every two weeks for eight months from the third week of September to the second week of June for two years.
Treatments are applied in two gallons of spray solution per 1,000 ft2 at 40 psi. Golf course traffic is simulated to replicate 73 rounds of golf a day by walking over the plots with golf shoes five days a week throughout the trial period. This corresponds to the average rounds of golf played at Trysting Tree Golf Club in Corvallis, Ore, during the same period.
Preliminary results show that greatest disease suppression and traffic tolerance is observed on treatments with 2.0 lbs. iron sulfate/1000ft2 in combination with 0.1 lb. of nitrogen per 1000 ft2 applied every two weeks.
Clint Mattox, Alec Kowalewski, Ph.D., and Brian McDonald are at Oregon State University.
