Leaf Curl (Taphrina spp.) refers to diseases cause deformed leaves (and sometimes flowers and fruit) on several stone fruits and forest trees.
Peach Leaf Curl is a serious problem in commercial crops of peaches and nectarines.
Symptoms: Parts, or all of the leaves thicken, becoming distorted and curled.
Affected leaves can become red-purplish, and later turn yellow-grey. In severe cases, blossom, young fruits and stems can be affected.
This disease can seriously reduce the vigour of the plant. The impact of the disease is most noticeable in early spring, as the first leaves, burst from previously dormant buds.
Bladder Plum - this is not widespread in Australia. It usually starts as white blisters on fruit; rapidly spreading. The fruit becomes distorted and the flesh spongy. Leaves and twigs can show symptoms like peach leaf curl.
Leaf Curls can affect Cherries (Cherry Leaf Curl and Witches Broom) also.
Oak Leaf Blister - this causes swollen patches on leaves. Badly infested plants can loose most of their leaves over summer.
General Control:
Hygiene such as the removal and disposal of infected parts. Garlic, and related species, planted at the base of susceptible tree is believed by some to give some degree of control. Spray Bordeaux at early bud swell (when the buds first start enlarging prior to bursting open). One spray usually works if the disease is caught before symptoms become severe.
Want to Learn More?
Check out publications in the ACS Bookshop: www.acsbookshop.com
For more information on Courses on Pests & Diseases:
In Australia: www.acs.edu.au/Courses/General-Horticulture-courses.aspx
In the UK: www.acsedu.co.uk/Courses/General-Horticulture-Courses.aspx