TAKE-ALL PATCH ON TURFGRASS Gaeumannomyces graminis   F A C T S H E E T

Introduction

Take-all Patch is a disease caused by the fungus Gaeumannomyces graminis. Bentgrasses (Agrostis spp.) are the most frequently injured species and may be killed by this pathogen. Bluegrasses (Poa spp.) and fescues (Festuca spp.) are sometimes attacked, but those grasses usually do not sustain severe infections and are more likely to survive under conditions where bentgrasses are killed.

Golf course putting greens or bentgrass fairways are the sites where this disease is most likely to occur. Newly seeded sites tend to be most susceptible to this fungus, especially where bentgrass in being established on soil with a high pH. The problem has been known to occur on where turfgrass is planted on recently cleared forest sites, soils with a high sand content, or soil that has been recently fumigated. it may also occur where a site has been recently or heavily limed or where. Over time (several years), this problem often disappears. It is thought that as other organisms build up in the soil, they out-compete this pathogen.

Symptoms

Symptoms of Take-all are most likely to appear in late spring as small sunken, water-soaked patches of turfgrass. Where turfgrass is stressed, the affected grass may initially appear red-brown before dying and turning a dull brown color. The roots and crown of infected plants become dark brown to black.

Figure 1: Symptoms of Take-all Patch on turfgrass.

Figure 2: Dark mycelium in roots of plants infected with Take-all Patch fungus.

Small circular areas of dull brown grass continue to expand throughout the growing season, spreading in size up to about 1 meter in diameter. Where mixed with other species such a bluegrasses or fescues, as the infected bentgrass dies out and the patch expands, the center often becomes dominated by the other grass species, giving it a frog-eye" appearance. In pure bentgrass plantings, all of the grass may be killed leaving behind a circular area of dull brown grass that does not quickly recover.

Disease Cycle

The fungus overwinters as mycelium in the thatch layer or on the tissues of perennial grass species. The fungus spreads by mycelium growing from one plant to another, invading the roots and crown of susceptible hosts. The fungus produces perithecia in the fall on infected plants. Ascospores from the perithecia may cause infection of aboveground parts in the spring, but this is probably rare. Symptoms begin to show up as the weather becomes warmer and drier.

Disease cycle for Take-all patch (caused by Gaeumannomyces graminis) (adapted from Asher and Shipton, 1981 and provided by APS Press, Compendium of Turfgrass Diseases, 2nd Edition)

Management Strategies

This disease may be difficult to manage, but correcting cultural, drainage and/or nutritional needs may help. If a soil test shows that nutrients such as potassium or phosphorus are low, then application of fertilizers containing these nutrients may help. Otherwise, use a fertilizer that had acidifying properties (ammonium sulfate, etc.). Avoid applying additional lime, but if necesary, use a coarse grade of lime that will not produce a quick or drastic change in the soil pH.

In addition to a high pH level in the soil, other factors that favor this disease include poor drainage or excessive irrigation that produces high soil moisture. Water deeply but infrequently when needed, and check the pH of the water and any top dressings that are used on the site to avoid raising the pH. Minimizing the pH (keeping it below 5.5) will help to minize the disease.

Some fungicides may be available to help manage this disease, but cultural practices should be corrected as well, and any other disease problems should be brought under control. Heritage is registered to help treat this problem in New York State. Some fenarimol products may also be used by professional applicators to treat golf course turf.

Updated, SLJ, 1/07