( Fusarium nivale )
A fungal disease which attacks lawns. Infection occurs at temperatures between 0°C and 8°C, conditions which are present under snow giving it the common name of Snow Mould. It appears later as irregular patches of yellow then brown grass up to 30cm in diameter when there is high humidity and temperatures of up to 18°C. This usually occurs between May and September. When damp conditions prevail the dead blades of grass become slimy and are covered in a light-pink bloom. It is transmitted by wind-borne asexual spores and the dormant phase is as mycelium in dead leaf matter during frosty or dry summer conditions.
To prevent infection, avoid using high nitrogen fertilizer in autumn as it produces lush growth in autumn and winter which is highly susceptible. Thatch in the grass creates the humid conditions required for development of the fungus so autumn scarifying should halt it. Avoid walking on the grass if it is covered with snow
Use a systemic fungicide such as thiophanate-methyl during the summer to kill any infection and prevent any further development. Carbendazim is related product which kills the mycelium.
Systhane Fungus Fighter which contains Myclobutanil is a systemic fungicide and although it does not list fusarium patch it shold attack the mycelium.
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