Turfgrass Diseases: Take-all Patch Bentgrass

SUBCRIBER

News

This disease, caused by the fungus Gaeumannomyces graminis var. avenae, usually affects 1- to 5-year-old bentgrass turf but may also destroy older stands. Take-all patch, a root and crown disease, kills plants and slows grass recovery. Annual bluegrass, fine fescues, and broadleaf weeds invade dead turf.

Take-all patches on colonial bentgrass fairways. Peter Landschoot, Penn State

Symptoms and signs

Take-all patch occurs as reddish-brown, yellow, or tan dead bentgrass in late spring or summer. Rings, crescents, or huge areas with annual bluegrass, fine fescue, or weed centers are disease signs. Older areas are buried and vary from a few inches to nearly 3 feet in diameter. Take-all patch kills bentgrass but not other grasses in mixed species stands. After hot, dry weather, grass stress causes symptoms. Affected roots and crowns are brown or black.

Trained diagnosticians often find dark brown hyphal threads (ectotrophic runner hyphae) and fungal mycelium on take-all patch-affected roots, crowns, and stem bases. Infected roots have dark brown vascular cylinders but clean cortical tissues. Infected crowns and leaf sheaths may have perithecia, spore-producing structures.

Figure 2. Creeping bentgrass tee take-all patch symptoms. Peter Landschoot, Penn State

Figure 3. Dead bentgrass circle with Chewings fescue and annual bluegrass in the middle. Peter Landschoot, Penn State

Figure 4. Ectotrophic runner hyphae of G. graminis on root surface of take-all patch-infected creeping bentgrass. Peter Landschoot, Penn State

Disease cycle

After bentgrass turf is developed, dark brown G. graminis runner hyphae grow on roots. Infected plant detritus on construction equipment, dirt from neighboring sites, or golfers’ shoes may transmit hyphal strands into new bentgrass stands. Spores seldom spread the virus. In chilly, damp autumn and spring, runner hyphae invade and infect roots. Pathogen-induced root impairment kills bentgrass plants in early to mid-summer heat and drought. In northern climes, G. graminis mycelium hibernates throughout winter but grows and causes illness in spring and summer.

Disease development

Take-all patch is most common in June–October on young bentgrass stands on sandy soils, freshly fumigated soils, or golf courses created in formerly wooded or wetland areas. These helpful microorganisms compete with or oppose the take-all patch pathogen, but their low numbers do not inhibit disease activity. Peak disease activity usually declines over 4–5 years due to the buildup of naturally occurring disease-suppressive bacteria that restrict fungal development. Liming to raise soil pH over 6.5, high pH topdressing on greens, and phosphate and manganese deficits also promote take-all patch formation.

Cultural control

Before turf patches appear, pathogen growth on roots should be controlled. An acidifying fertilizer like ammonium sulfate may reduce soil pH in high pH soils (>6.5). In hot (>80oF) weather, high rates of ammonium sulfate may burn turfgrass, therefore apply and water modest rates in spring and autumn. This method may inhibit take-all patch for months or years, depending on soil type, pH, and ammonium sulfate treatment frequency/rate.

In chronic take-all patch instances with low manganese soil testing, 2 lb soluble manganese per acre as manganese sulfate has reduced disease severity. To prevent foliar burn, manganese sulfate should be sprayed in spring with enough water to penetrate the rootzone.

Chemical control

Penetrant fungicides that impede G. graminis growth and infection before turf symptoms occur help reduce take-all patch. The estimated patch symptom development dates will determine fungicide application schedule. Fall fungicide sprays may be necessary for greens, tees, and fairways that show symptoms in early to mid-spring. For late spring or summer outbreaks, early spring fungicide treatments followed by 21- to 28-day repeat applications usually work well.

Because take-all patch is caused by a root and crown-infecting fungus, fungicide treatments should be administered with substantial spray volumes (up to 5 gallons of water per 1000 sq ft) to ensure considerable active ingredient concentrations reach the crown and upper root system. Instead of using huge spray volumes, apply the fungicide in the morning and immediately irrigate the treated area with enough water to wash spray droplets off the canopy and into the surface soil where crowns and roots reside.

Turf managers should know that fungicide regimens for severe take-all patch outbreaks are unpredictable and seldom effective.

Some penetrant fungicides labeled for control of take-all patch disease.

Some combination product fungicides labeled for control of take-all patch disease.

FRAC means Fungicide Resistance Action Committee. P = host plant defense inducers; M = multi-site fungicides; and U = unknown mode of action and unknown resistance risk. Turf managers should rotate fungicides from various FRAC codes/resistance groups to prevent fungicide resistance.

**Plant mobility classification refers to a fungicide’s ability to penetrate plant surfaces or remain on plant leaf or stem surfaces without penetration. Fungicides that penetrate plant surfaces and are translocated mostly upwards through plant xylem tissues are called acropetal penetrants (acropetal = toward the apex). Fungicides that enter plant cuticles or move limited distances in internal plant spaces, but do not translocate through vascular tissues (xylem and/or phloem) are called local penetrants. Contact fungicides do not penetrate plant surfaces and only inhibit fungal pathogens residing on leaf and stem surfaces.

Related Questions

• What is the take all patch on bentgrass greens?

  Gaeumannomyces graminis causes take-all patch. It occurs on all bentgrass species in temperate regions worldwide. It is most severe on freshly established creeping bentgrass stands and infrequent on undisturbed turf over 10 years old.

• What is best fungicide for take all patch?

  Ammonium and manganese sulfates diminish take-all severity. Drain water.

• What are the conditions for take all patch?

  Conditions Favoring Disease
  In California, take-all patch principally occurs in late fall and winter when air temperatures are 50° to 60°F and soils are wet or moist, but symptoms may not manifest until the turf is exposed to periods of drought or heat stress.

• Is take all patch a foliar disease?

  Golf courses are infected. Circles, patches, wilting, and inconsistent coloration are signs. Foliar signs include browning and yellowing. During May, June, July, August, September, and October.

• What is the best bentgrass for putting green?

  Creeping bentgrass

  Premium putting greens use creeping bentgrass, a northern cool-season grass. Balls roll effortlessly on the highly textured blades for rapid, smooth play.

• What is the best fertilizer for bentgrass?

  Bentgrass fertilizer recommendations? Bentgrass grows best with soluble nitrogen fertilizers supplied at light rates every 10 days after sowing until a full cover develops. Bentgrass seeds best in early autumn in the South.