Powdery mildew - Grapes

Erysiphe necator

Powdery mildew (Erysiphe necator) is a widespread and common disease of grapes in New Zealand. Obvious as white spots which can spread across leaves producing a grey-white sporulation. Bunches are also infected with the characteristic grey-white sporulation symptoms. Winemakers detest powdery mildew as even minor infection of grapes has a detrimental effect on subsequent wine quality.

Read about using Luna Sensation to control Powdery Mildew in grapes

Related Diseases

Botrytis

Botrytis cinerea

Often called grey mould, Botrytis cinerea in wet seasons is responsible for the greatest crop losses in vineyards. Classically appears as bunch infections of browning berries with grey sporulation. Late season berry slip skin is also caused by botrytis. Botrytis can also be an issue in other crops including citrus, kiwifruit, onions strawberries and berryfruits.

Brown Rot

Monilinia fructicola

Brown rot (Monilinia fructicola) is the most common and destructive disease of stonefruit crops in New Zealand. Obvious symptoms are brown circular spots on fruits which enlargen as a firm, dark-brown decay over the fruit surface often producing a brown –white sporulation mass. Brown rot is more problematic in wetter seasons.

Sour Rot

Sour rot is a late season disease of grape bunches that causes a soft watery rot that has a distinct vinegar odour. Berries change colour and infection can quickly spread through bunches. Sour rot is caused by a complex of undesirable yeasts and bacteria and is often associated with botrytis infections. Sour rot gains entry through wounds from birds, berry splitting etc.