Fire blight

Erwinia amylovora

Fire blight is a devastating bacterial disease (Erwinia amylovora) of pears but can also attack apples. Symptoms of infection are well named with wilting foliage that has a black “burnt” look. Typically seen on young, vigorous growth. Moisture and mild temperatures during the blossom period favour infection.

Related Pests

Powdery Mildew - Apples

Podospara leucotricha

Powdery mildew (Podospara leucotricha) can be a serious disease of apples in drier areas of New Zealand. Powdery mildew usually attacks young leaves, shoots and flowers with severe infestations stunting trees. Seen as whitish felt patches of spores more commonly on the undersides of leaves but can spread to cover the whole leaf.

Black Spot

Venturia inaequalis

Black spot (Venturia inaequalis) is a serious disease for New Zealand apple growers. Also known as apple scab, if not adequately controlled it can result in massive losses of marketable crop. Typical symptoms are circular black spots on leaves and fruits. On fruits the spots can coalesce resulting in cracks and rots. Black spot infection and spread is favoured by wet and mild weather. A similar but different species, Venturia pirina causes black spot in pears.

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.