Fusarium Patch
General description
Fusarium Patch also known as snow mould is caused by the fungus Microdochium nivale. It is one of the most damaging diseases for grass and once active can be difficult to control.
What are the symptoms?
Starts with the appearance of dark and water-soaked patches as pictured below developing into orange/brown circular spots that typically increase in size as seen above. In moist weather or following snow melt when the disease is active the areas may also be covered by white, grey or pale pink fluffy mould.
What are the susceptible grass species?
Annual meadow grass (Poa annua) is particularly susceptible to Fusarium patch but it can also affect Perennial ryegrass. Bent grasses and fescues are also at risk but these are not widely seen in winter sports turf.
What time of year and under what conditions does it appear?
👉 It is not terribly common in recreational football settings but can be particularly noticeable after snow melt, when it gets the nickname snow mould.
👉 If conditions are right Fusarium patch can occur year-round but is most prevalent and damaging between late autumn and early spring during mild and moist weather.
👉 As previously mentioned, pitches that are predominantly annual meadow grass are most at risk in humid conditions where the surface remains wet for extended periods.
👉 Areas that are shaded may be particularly susceptible.
👉 It is more prevalent in alkaline soils with thatch layers.
👉 Mistimed applications of Nitrogen will encourage disease.
👉 Heavy applications of topdressing during susceptible conditions may also encourage an outbreak.
What are the effects on turf?
Fusarium patch can seriously damage the playing surface leaving 12-inch patches of bare ground which effect both the playability and presentation of the pitch.
Prevention and management
Cultural
🍃 Removing surface moisture, (switch or brush when dew occurs) to reduce the occurrence of humid surface conditions
🍃 Surface aeration and grooming to encourage air flow and minimising thatch through scarification and verti-cutting
🍃 Avoid applications of high Nitrogen containing fertilisers when the conditions are not appropriate, autumn to early spring applications should be high in Potassium but low in Nitrogen.
🍃 If you have high pH, use acidifying fertilisers such as ammonium sulphate to reduce it.
If shaded areas are caused by trees etc, try and manage this where possible.
🍃 Try and maintain a grass sward with as little annual meadow grass as possible.
🍃 Avoid heavy applications of top dressing when at risk conditions are present as outline above.
🍃 Iron and Potassium applications to harden the turf prior to and throughout the at-risk period will
help.
💡 Top tip – Avoid any traffic both machinery and people on affected turf as this increases the risk of spreading the disease. If you must carry out maintenance clean equipment thoroughly after use.
Chemical
Fungicidal treatments will need to be applied by a qualified professional but are very expensive and best applied preventatively or at the very earliest signs of disease. Once the disease has reached the brown/orange stage the fungicide will only help mitigate the further spread of disease rather than eradicate existing disease.