Take-all Patch

Table of Contents

1. Introduction
2. History
3. Take-all Patch Host and Symptoms
4. Disease Diagnosis
5. Cultural and Chemical Control

Introduction

Take-all patch is one of the many patch diseases that attack turfgrass. The patch diseases are root pathogens that attack the roots and crowns. The name "patch disease" comes from the symptoms which result from the disease. These diseases cause turf to die out in a circular pattern. As the patches mature, other grass or weed species may invade the patch giving it a doughnut or "frog-eye" appearance.

History

Take-all patch was first reported as a severe disease on bentgrass in Holland in the 1930's. It was first confirmed on bentgrass in North America in 1960 in the Pacific Northwest. In the Great Lakes region, the first confirmed report on bentgrass was made in the mid-1970's. The first reports of Take-all patch in Canada were from southwestern Ontario in the mid-1980's. Since then, positive identification of Take-all patch has been made in southern British Columbia and other parts of southern Ontario. It is also reported to occur in the Atlantic provinces as well.

Take-all patch is a disease which mainly attacks newly constructed bentgrass putting greens. Because of this, there was a large increase in this disease in the years following the golf course construction boom in the late eighties. With the trend towards bentgrass fairways, there was also an increase in the occurrence of this disease on fairways as well as greens. In many parts of Canada we are experiencing another wave of active golf course construction. The result of this will most likely be another wave of Take-all patch in the not too distant future.

Take-all Patch Host and Symptoms

Take-all patch, formerly known as Ophiobolus patch, is caused by the Gaeumannomyces graminis. It is primarily a problem on creeping bentgrass. It is commonly a problem on newly constructed sand based bentgrass greens or greens constructed in areas that were previously forested. It is more severe on greens where the soil pH is greater than 5.5. It is favoured by high soil moisture, poor drainage and excessive irrigation. It may take one to two years for the disease symptoms to show up. Over time, usually about ten years, the disease will become less severe and eventually disappear altogether. This is presumed to be because of a build up of antagonistic or competing microorganisms. Greens that are irrigated with high pH irrigation water may have the disease for a longer period of time.

Take-all patch symptoms begin as small depressed circular patches. Over time these may expand up to 0.5 - 1 metres in diameter. The turf in the patch is a light straw colour. When the disease is active the outer edge may have a bronze appearance similar to Fusarium patch. Resistant grasses and weeds may invade the centre of the patch giving it a "frog-eye" appearance (Figure 1). Poa. and Festuca spp. are often found colonizing the centres of Take-all patches. Over time the patches may coalesce to form irregular larger patches.

Figure 1: Frog-eye appearance of Take-all patch.

The fungus overwinters as mycelium on roots and crowns of infected plants. As the disease becomes active during cool, wet weather in spring and fall, it is spread from infected roots to healthy adjacent roots. Symptoms are often masked at this time and become apparent during hot, dry weather. The fungus grows in roots producing darkly pigmented "runner hyphae" (Figure 2). These structures plug up the vascular tissue of the roots blocking water and nutrient uptake. Severely infected plants will have "runner hyphae" throughout the crown of the plant as well. In addition, small black fruiting structures that are beaker shaped called perithecia can form during the autumn on infected plant crowns. The presence of runner hyphae is used to diagnose this disease. All runner hyphae produced by the patch disease look the same.

Figure 2: Runner hyphae of the Take-all fungus.

Disease Diagnosis

To make a completely accurate diagnosis, the pathogen would need to be isolated, cultured and forced to produce a perithecium. This process is time consuming and not always successful. A reliable disease diagnosis can be made based on the host plant that the runner hyphae are found invading. Each patch disease has a very narrow host range, so you can be fairly accurate with your diagnosis this way. If the runner hyphae are found only in the creeping bentgrass plants, you can be fairly certain that the disease is Take-all patch.

Cultural and Chemical Control

Take-all patch is difficult to control. Promote good rooting by applying a late fall application of fertilizer and delay spring fertilization until mid-to-late May. Control thatch and aerify frequently to promote deep rooting. Avoid using alkaline topdressing material. Ensure that there are adequate levels of phosphorus, potash, magnesium, manganese, copper and zinc. One of the best methods to help control this disease is to try to maintain an acidic soil pH. This can be accomplished by using an acidifying fertilizer such as ammonium sulfate at a rate of 1.5-2.5 kg/N/100m² per season. Wettable sulfur may also be used to attempt to acidify the soil. On putting greens apply at a rate of 250g/100m² in split applications in spring and fall. On extremely calcareous based sands the sulfur is not often successful in controlling Take-all patch. It has also been suggested that acidification of irrigation water that has a pH greater than 7.5 might also help to control this disease. There is no data to-date to prove this hypothesis. Using resistant creeping bentgrass cultivars is not an option, as there are no know creeping bentgrass cultivars that are resistant to Take-all patch. For current fungicides registered for use on Take-all patch, please refer to OMAFRA Pub. 384, Recommendations for Turfgrass Management.