Description of the Disease
Take-all patch appears as circular or ring-shaped dead areas that range from a few inches up to 3 feet or more in diameter. Dying bentgrass at the advancing margins of these areas has a purplish tinge. The roots of the diseased plants are rotted and have dark strands of mycelium visible on the surface of the roots. Large black perithecia, which are globular or flask-shaped fungal fruiting bodies, may be visible with the use of a hand lens. The pathogen survives in grass debris and living grass plants.
Susceptible Turfgrasses
Bentgrasses are the most susceptible, but bluegrass, fescues, and ryegrasses are also susceptible to 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. Soil conditions that favor the disease include light texture, low organic matter, low or unbalanced fertility, high pH, and high moisture. The disease may be spread by spores produced by the perithecia, in infested soil and sod, or by dethatching and aerification equipment.
Management
To prevent the development of this disease, make sure the turfgrass has adequate soil drainage and fertility.
Cultural Control
Recovery of bentgrass can be slow on closely mowed turf; affected areas can be resodded if necessary, and some varieties with improved tolerance are available. Raising manganese levels in the soil (or lowering pH) appears to suppress the disease. If the soil pH is above 7, lower it using elemental sulfur. Fertilize in fall with ammonium sulfate. Also, irrigate based on evapotranspiration needs of turfgrasses.
Treatment Decisions
Fungicides may be necessary on golf greens that have experienced the disease in the past. Apply a fungicide on a preventive basis in fall.
| Common name | Amount to use | Ag Use REI‡ |
NonAg Use REI‡ |
|
|---|---|---|---|---|
| (Example trade name) | (hours) | (hours) | ||
| Not all registered pesticides are listed. The following are ranked with the pesticides having the greatest IPM value listed first—the most effective and least likely to cause resistance are at the top of the table. When choosing a pesticide, consider information relating to the pesticide's properties and application timing, honey bees, and environmental impact. Always read the label of the product being used. | ||||
| A. | AZOXYSTROBIN | |||
| (Heritage) | 0.4 oz/1000 sq ft | 4 | Until dry | |
| MODE-OF-ACTION GROUP NAME (NUMBER1): Quinone outside inhibitor (11) | ||||
| B. | MYCLOBUTANIL | |||
| (Eagle 20EW) | 2.4 fl oz/1000 sq ft | 24 | Until dry | |
| MODE-OF-ACTION GROUP NAME (NUMBER1): Demethylation inhibitor (3) | ||||
| C. | PROPICONAZOLE | |||
| (Banner Maxx) | 2–4 fl oz/1000 sq ft | 12 | Until dry | |
| MODE-OF-ACTION GROUP NAME (NUMBER1): Demethylation inhibitor (3) | ||||
| 1 | Group numbers are assigned by the Fungicide Resistance Action Committee (FRAC) according to different modes of action. Fungicides with a different group number are suitable to alternate in a resistance management program. In California, make no more than one application of fungicides with mode-of-action group numbers 1, 4, 9, 11, or 17 before rotating to a fungicide with a different mode-of-action group number; for fungicides with other group numbers, make no more than two consecutive applications before rotating to a fungicide with a different mode-of-action group number. |
| ‡ | Restricted entry interval (REI) is the number of hours (unless otherwise noted) from treatment until the treated area can be safely entered without protective clothing. Agricultural use applies to sod farms and commercial seed production. |