Preventing Anthracnose In Annual Bluegrass

Anthracnose in annual bluegrass often appears during periods of slow growth and stress. Since recovery is slow during these periods, prevention is critical. Rutgers University has led the extensive research on this disease advancing our understanding of its control.
  • Long-term cultural management strategies
    • Any practice to increase photosynthesis will help reduce anthracnose including maximizing leaf area (higher mowing height), increasing light exposure and using products with proven Stressgard® technology.
    • Maintain mowing heights ≥ 0.125 inches and consider rolling or double mowing to maintain green speeds.
    • Fertility:
      • Apply 0.1 to 0.15 lb. N/1,000 sq. ft. weekly in the summer months.
      • Potassium soil levels in the “Adequate” range can help limit anthracnose.
    • Apply frequent light sand topdressing, but limit application rates so topdressing can be watered-in or brushed-in with one pass to limit stress.
    • Irrigate at 60-80% base ET to prevent moisture stress in already shallow-rooted Poa annua.
  • Fungicide solutions
    • Fungicide applications should be initiated when 2" soil temperatures taken daily at 11 am average 65-68°F for five consecutive days.
    • Mirage® Stressgard is highly effective alone or in combination with Primo Maxx® (Syngenta) during the summer months with no negative growth regulation effects. (See Oregon State data in Figure 1)
    • Signature® XTRA Stressgard applications on 7 to 14 day intervals for Pythium control and plant health will also provide anthracnose control when combined with Daconil® (Syngenta).
  • For more information – See the attached Green Solutions Sheet for more information and contact your Bayer Area Sales Manager.

Figure 1. Mirage/Primo Interaction Study, Poa annua Green. Effect of Mirage or tebuconazole with and without Primo on visual quality of a Poa annua putting green. Applications were made every two weeks starting on July 1. Ratings were recorded on July 24 and August 7. Oregon State University, 2014.


Leaf chlorosis followed by thinning is typical with anthracnose in annual bluegrass. Photo: Zac Reicher, Ph.D., Bayer.

Extreme anthracnose damage in a difficult growing environment. Photo: Derek Settle, Ph.D., Bayer.

  Bayer Solutions - Anthracnose - Cool
Rob Golembiewski

by Rob Golembiewski , Ph.D., Green Solutions Team Specialist

Monday, April 29, 2019

Paul Giordano

by Paul Giordano , Ph.D., Green Solutions Team Specialist

Monday, April 29, 2019