Now is the perfect time to see Fusarium patch, also known as Microdochium patch, on close mown fine turf surfaces. In the UK it is the most common disease of intensively managed turf and whilst it can occur at any time of year, it is undoubtedly most damaging in autumn and early winter when mild, wet weather prevails.
With a reduction in fungicide availability and products giving shortened periods of control, managing this disease at this time of year is becoming increasingly difficult. It is almost impossible to completely prevent Fusarium patch disease and therefore acceptance of a certain level of disease activity is a necessity. Communicating this message to golfers is the first step in helping reduce the impact of any disease activity that does occur.
What Causes It?
Typically found on annual meadow-grass dominated turf Fusarium patch can appear as small orange to brown spots of 20 mm in diameter that may increase in size to form larger patches. Under prolonged humid conditions, sparse white or pink mycelium may be seen around the edges of each patch which tends to mat the green leaves together. A pale straw colour indicates that the disease has become less active, perhaps due to a change to drier conditions. A lush sward is more vulnerable to this disease, as is turf located in a shaded environment or where air movement is restricted. Fusarium patch is also favoured by the presence of organic matter in the soil profile, as this is moisture retentive and the dead plant material is a natural substrate for the disease.
Why The Concern?
Surface scars that occur at this time of year, when grass growth is slowing, can remain pitted for months until damage recovers and the sward grows back in. This can often take until the following spring, meaning visible surface damage for four months or more. Staff time plugging and repairing damage can be significant.
Aquatrols Top Tips for Reducing Levels of Disease
- Use turf fungicides as necessary
Adopt a preventative fungicide management strategy in conjunction with good cultural techniques to achieve the best outcomes in terms of minimising aggressive disease whilst at the same time reducing reliance on turf fungicide products.
- Reduce organic matter levels
If appropriate, reduce thatch or organic matter levels though appropriate thatch reduction techniques during the main growing season using aeration and sand top dressing methods to lower organic matter values particularly in the critical 0-40 mm depth from the surface.
- Maintain dry turf surfaces
The longer the turf leaf stays wet, the greater the risk of disease. Incorporate management practices that help keep the turf surface dry, such as spiking or slitting. Installation of new pipe drainage may also be required if drainage is particularly poor. Incorporate a suitable penetrant wetting agent such as Dispatch Sprayable into the programme to speed surface water infiltration rates. Control dew formation through regular switching and use of dew dispersal surfactants.
- Maximise sunlight and air movement
This can make an important difference to year-round plant health and reduce aggressiveness of any autumn disease. Consider tree and vegetation removal if appropriate to increase sunlight levels, particularly early morning winter sunlight as well as opening up corridors on the prevailing wind direction.
- Manage turf nutrition
Soft, lush, overfed turf is particularly vulnerable to Fusarium patch disease however at the same time sufficient nutrition needs to be applied to maintain healthy turf while conditions remain mild. This can be a difficult balance to achieve. Too little or too much nitrogen increases the grass plant’s vulnerability to disease.
- Control turf surface pH
Avoid sports sands or top dressings that contain lime – check regularly with material suppliers. Make applications of iron sulphate during the autumn and winter months to acidify the immediate turf surface and make it a more hostile environment for Fusarium patch disease.
- Manage moisture
Employ effective, appropriate surfactant programmes during the spring and summer growing season using proven, reliable products. Drought stressed turf will tend to be more susceptible to Fusarium patch disease activity once soil moisture levels return. Managing soil moisture carefully all year round will help reduce the potential for destructive autumn disease.
The Aquatrols Mission
Aquatrols is committed to pioneering new methods that advance soil and plant health for turf, agriculture and horticulture. As autumn and winter weather conditions make the development and retention of high-quality turf surfaces more difficult, the use of surfactant technology can have a critical role to play in year-round turf management.
For more information, please contact your local Aquatrols Account Manager.