Fruit Science Commons^™

Shothole Of Stone Fruit, Department Of Agriculture, Western Australia

Journal of the Department of Agriculture, Western Australia, Series 4

Shothole disease is most damaging on almonds and early-flowering peaches and apricots but can also affect nectarines, plums and cherries.

The causal fungus IStigmina carpophila) survives the summer in infected buds and twig cankers.

The autumn rains then stimulate production of spores which infect other twigs, buds and subsequently the new spring growth.

Powdery Mildew Of Apples, Department Of Agriculture, Western Australia

Journal of the Department of Agriculture, Western Australia, Series 4

Powdery mildew (Podosphaera leucotricha) markedly affects the growth and vigour of susceptible apple varieties, particularly Jonathan and Cleopatra.

The fungus survives the winter as mycelial threads in dormant buds on spurs and laterals infected the previous season. At bud-burst the mycelium grows onto the developing leaves and blossom clusters to form white patches.

Spores produced on these patches are spread by the wind onto the healthy growth.

Brown Collar Rot Of Citrus, Department Of Agriculture, Western Australia

Journal of the Department of Agriculture, Western Australia, Series 4

Infection of fruit and foliage by brown rot fungi (Phytophthora spp.) occurs after opening rains in autumn. It can continue during periods of wet weather until spring.