Apple scab or black spot is a fungus that infects leaves, shoots, buds, blossoms and fruit. It is more prevalent in regions with high rainfall and relative humidity during the growing season.
Plant Part: Leaves, shoots, blossoms and fruit
Season: Symptoms will be noticeable from Late Spring
Symptoms: If your Fruit Salad Tree is infected the first symptoms will usually appear as small spots on the underside of young leaves or as spots on either surface of older leaves. The spots may grow into one another to form large patches. If the disease has spread to the fruit, it will develop black spots and go corky in the centre.
Control: A copper oxychloride spray can be applied when your tree is at the green tip stage of growth. (when the buds are broken at the tip and about 1/16 inch of green tissue is visible - generally early to mid-September). If you have missed out spraying in September, then consider applying Mancozeb in the month of October.
Prevention: Keep the undergrowth area clean; The fungus usually survives over winter under the trees, in the dead, infected leaves from the previous season. Avoid use of overhead irrigation, which could begin or prolong scab infection periods.
References: NSW Department of Primary Industries, Department of Agriculture & Food Western Australia, Agriculture Victoria, and our FST team.
