Powdery Mildew - Beet

Erysiphe betae
Powdery mildew (Erysiphe betae) is commonly seen in New Zealand beet crops as greyish-white mycelium on leaves. Favoured by hot weather, severe attacks can significantly reduce yields and feed value of fodder beet crops.
Powdery mildew beet

Main Host

Fodder and sugar beet.


Powdery mildew first appears as small surface patches of white, fluffy mycelium. The first symptoms are usually found on the underside of older leaves but it can rapidly spread so that the entire plant appears greyish-white.

Life Cycle

To overwinter, powdery mildew must have living beet material (fodder beet, sugar beet, spinach, swiss chard etc.) to survive. In the spring, wind borne spores are responsible for the infection of new crops with periods of humidity and temperatures of around 25ÂșC being ideal.

Weather Conditions

Hot, humid conditions, but without moisture present on the leaves are optimum for disease development.

Economic Impact

Severe attacks can significantly reduce the yield and feed value of fodder beet. Overseas, sugar beet yield losses of up to 35% have been recorded.


Escolta has a label claim for the control of powdery mildew.

Powdery mildew beet infection

Powdery mildew infection

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