See:
Wheat (Triticum aestivum) - Take-all
Cause Gaeumannomyces graminis var. graminis (formerly Ophiobolus graminis), a fungus that overwinters on turf debris and in the perennial portions of the grass plants. It is a wet-weather disease, spreading from plant to plant by growing over roots, rhizomes, and other plant parts and by adhering to equipment. In Oregon, it probably has been diagnosed incorrectly as the fairy-ring disease in many instances.
The disease is common in bentgrass and most severe on bentgrass growing in sandy soils under high fertility in stands 1 to 4 years old; incidence declines after 5 years. The disease also can be on other turf grasses. Weeds and annual bluegrass frequently invade the center of the circle where turfgrass has been killed. G. graminis is also an important pathogen of wheat, oats, barley, and rye.
Symptoms Areas are reddish brown at first, later brown to gray, usually circular, and 2 to 36 inches or larger in diameter. Both shoots and roots are killed. Patches may coalesce to form large areas of dead or declining turf.
Cultural control
- Plant bentgrass in mixtures with fine fescues and perennial ryegrass, which are less susceptible to the disease.
- Maintain soil pH below 5.5.
- Maintain balanced nutrition. For established turf, use a balanced N-P-K ratio such as 6-1-4.
- Spray with wettable sulfur, two (2) applications of 1.25 lb/1,000 sq ft, 1 month apart in early spring. 24-hr reentry. On putting turf, use no more than 0.5 lb/1,000 sq ft per application. Split applications (fall and spring).
- Adding lime in the absence of sulfur can incite disease, even in mature stands. If lime is necessary, use coarser grades and continue with regular sulfur applications.
Chemical control
- Densicor at 8.5 fl oz/A or 0.196 fl oz/1,000 sq ft. Do not use hand held equipment. Group 3 fungicide. Reenter when sprays have dried.
- Disarm 480 SC at 0.36 fl oz/1,000 sq ft. Group 11 fungicide. 12-hr reentry.
- Eagle 20 EW at 2.4 fl oz/1,000 sq ft. May produce a growth regulation effect on Kentucky bluegrass. Group 3 fungicide. 24-hr reentry.
- Fame SC at 0.4 fl oz/1,000 sq ft. Group 11 fungicide. 12-hr reentry.
- Heritage at 0.2 to 0.4 oz/1,000 sq ft. Group 11 fungicide. 4-hr reentry.
- Insignia SC at 0.7 fl oz/1,000 sq ft. Do not use with organosilicate adjuvants. Group 11 fungicide. 12-hr reentry.
- Maxtima at 0.8 fl oz/1,000 sq ft. Group 3 fungicide. 12-hr reentry.
- Mirage at 1 to 2 fl oz/1,000 sq ft. Water into root zone after application. Group 3 fungicide. 12-hr reentry.
- Monsoon Turf at 0.6 fl oz/1,000 sq ft. Group 3 fungicide. 12-hr reentry.
- Pinpoint at 0.31 fl oz/1,000 sq ft. Apply to dry turf or after mowing. Group 11 fungicide. 12-hr reentry.
- PropiMax EC at 0.73 to 1.45 fl oz/1,000 sq ft. Group 3 fungicide. 12-hr reentry.
- Tebuzol 3.6F at 0.6 fl oz/1,000 sq ft. Group 3 fungicide. No reentry interval listed.
- Torque at 0.6 to 1.1 fl oz/1,000 sq ft. Do not mix with growth regulators during hot weather as injury may develop. Group 3 fungicide. 12-hr reentry.
- Tourney EZ at 0.37 oz/1,000 sq ft. Do not apply to Poa annua putting greens. Group 3 fungicide. 12-hr reentry.
- Trinity at 1 to 2 fl oz/1,000 sq ft. Do not mix with growth regulators during hot weather as injury may develop. Group 3 fungicide. 12-hr reentry.
Combination Fungicides
- Armada 50 WDG at 1.2 to 1.5 oz/1,000 sq ft. Do not use a silicone-based surfactant. Group 3 + 11 fungicide. 12-hr reentry.
- Briskway at 0.5 to 1.2 fl oz/1,000 sq ft. Can be used in hot weather. Group 3 + 11 fungicide. Reentry when sprays have dried.
- Concert at 8.3 fl oz/1,000 sq ft. Do not use on fine fescue turf. Group 3 + M5 fungicide. 12-hr reentry.
- Headway at 1.5 to 3 fl oz/1,000 sq ft. Do not use with silicone-based surfactants or EC formulations. Group 3 + 11 fungicide. 12-hr reentry.
- Heritage Action at 0.2 to 0.4 oz/1,000 sq ft. Alternate with other fungicides. Group 11 + P1 fungicide. 12-hr reentry.
- Honor at 1.1 oz/1,000 sq ft. Group 7 + 11 fungicide. Golf course turf only.
- Lexicon at 0.34 to 0.47 fl oz/1,000 sq ft. Group 7 + 11 fungicide. 12-hr reentry.
- Navicon at 0.7 to 0.85 fl oz/1,000 sq ft. Group 3 + 11 fungicide. 12-hr reentry.
- Pillar G at 3 lb/1,000 sq ft. Group 3 + 11 fungicide. 12-hr reentry.
- Premion at 6 to 8 fl oz/1,000 sq ft. Group 3 +14 fungicide. Reentry when sprays have dried.
- Tartan at 1.5 to 2 fl oz/1,000 sq ft. Group 3 + 11 fungicide. 12-hr reentry.
Reference Thomas, S.L., Bonello, P., Lipps, P.E., and Boehm, M.J. Avenacin production in creeping bentgrass (Agrostis stolonifera) and its influence on the host range of Gaeumannomyces graminis. Plant Disease 90:33-38.