Summer Fungicide Trials

The trials listed below are standard research trials where product efficacy is tested every year. Each trial is visually rated for disease severity (% disease) and turfgrass quality, and turfgrass color is measured using a GreenSeeker color meter from Trimble. In addition, an electronic record of each fungicide application for each trial and the environmental conditions (i.e. air temp, soil temp) present during the application will be compiled and available upon request at the end of the season. For more information on these trials or to inquire about additional trials please contact Paul Koch.

Dollar Spot (Sclerotinia homoeocarpa)

Four different dollar spot trials are initiated every year. If submitting a treatment to test for dollar spot efficacy, please specify which specific dollar spot trial the treatment is to be included in. All dollar spot trials rely on natural inoculum to cause disease.

Preventative dollar spot at putting green height

Completed on ‘Penncross’ creeping bentgrass and annual bluegrass grown on an 80:20 sand:silt rootzone. Maintained at a mowing height of 0.140″. Monthly sand topdressing applications and annual nitrogen fertilization rates of 1-2 lbs per 1000 sq ft mimic golf course conditions. Plot size is 3 X 5 ft with 4 replications. Fungicide applications are made immediately prior to dollar spot development, usually around June 1st, and continue until the middle to end of August.

Preventative dollar spot at fairway height

Completed on ‘Pennlinks’ creeping bentgrass grown on natural soil and maintained at a mowing height of 0.5″. Anunal nitrogen fertilization rates are approximately 2 lbs per 1000 sq ft. Plot size is 3 X 5 ft with 4 replications. Fungicide applications are made immediately prior to dollar spot development, usually around June 1st, and continue until the middle or end of August. Dollar spot disease pressure is often higher in the fairway trial than the putting green trial.

Early-season dollar spot control

Completed on ‘Penncross’ creeping bentgrass grown on natural soil and maintained at a mowing height of 0.5″. Plot size is 3 X 10 ft with 4 replications. One fungicide application is made in early May, and the length of efficacy is rated until no differences between treated plots exist.

Curative dollar spot control

Completed on ‘Penncross’ creeping bentgrass maintained at either putting green or fairway height. Plot size is 3 X 10 ft with 4 replications. Dollar spot levels are allowed to reach an approximate 30% level of disease, before 2 applications of each fungicide are applied two weeks apart. Disease and quality ratings are made immediately prior to the first fungicide application, prior to the second application, and 2 weeks following the second application.

Brown Patch (Rhizoctonia solani)

Completed on colonial bentgrass stand maintained at 0.5″. This stand was seeded in 2010 for use specifically to test fungicide efficacy against brown patch. Each plot is inoculated with R. solani prior to the first fungicide application. Irrigation and nitrogen fertilizer rates are also increased to increase disease severity. Plot size is 3 ft X 10 ft with 4 replications.

Pythium blight (Pythium spp.)

To ensure adequate disease pressure to differentiate effective products, entries in the Pythium blight study will be included in both a field trial and a growth chamber study at no additional cost. The field study is completed on juvenile perennial ryegrass plants seeded in early May and maintained at 0.5″. The plot is inoculated with Pythium aphanidermatum prior to fungicide application. Following the fungicide application, a permeable plastic tarp is placed over the trial to increase heat and humidity and to encourage disease development. Treatments are rated for 2-3 weeks following the fungicide application. In the growth chamber, 2-4 week old ‘Penncross’ creeping bentgrass plants in 4″ pots are inoculated with P. aphanidermatum following fungicide application and placed in a growth chamber keeping temperatures at approximately 32C and relative humidity over 90%. Disease severity ratings will be taken daily for 7-10 days.

Anthracnose (Colletotrichum cereale)

Completed on annual bluegrass fairway at a local golf course maintained at 0.5″. Plot size is 3 X 10 ft with 4 replications. Disease severity and turf quality are monitored throughout the growing season.

Fairy ring (Many basidiomycete fungi)

Entries into the fairy ring trial will automatically be included in both the preventative and curative trials at no additional cost. In the preventative trial, two preventative applications 14 days apart are made on a plot at the OJ Noer with a history of fairy ring when soil temperatures approach 50°F. Plot size is 3 X 10 ft with 4 replications, and plots are monitored throughout the growing season. In the curative trial, 2 applications are made to a site in southern Wisconsin experiencing extensive fairy ring symptoms. Plot size is 3 X 10 feet with 4 replications, and plots are monitored for disease severity the remainder of the growing season.

Seasonal Program

Complted on a mixture of creeping bentgrass and annual bluegrass maintained at 0.100″. Entire season-long fungicide programs produced by the cooperator are completed. Plot size is 3 X 10 ft with 4 replications. Please note that due to the increased length and intensity of this study that individual treamtments cost $1,000.