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Peach leaf curl

Picture: Department of Agriculture and Food WA

Gardeners who have grown stone fruit such as peaches, nectarines or apricots may have noticed in some years the leaves become strangely crinkly and bright pink.

This is due to a fungal disease known as peach leaf curl. Needless to say, it affects more than just peaches.

The fungus is called Taphrina deformans, giving you a hint that it causes deformity in the leaves.

The peach leaf curl fungus will appear in the first leaves that will be bright pink, then become thick and twisted. The leaves can look like a pappadum cooking in the microwave.

All infected parts will have a whitish bloom and the leaves eventually shrivel up and fall of. The shoots of infected trees become swollen, pale green to yellow in colour, stunted and sometimes gum oozes out.

Apricot trees produce a strange sort of witch's-broom growth with dense leaves clustered together.

Infected trees drop many of their flowers, meaning less fruit production. The spores will overwinter underneath bud scales and twigs and emerge at bud burst aided by water splash and wind.

Timing is everything in controlling peach leaf curl. You will need to spray the whole tree thoroughly, including all twigs, with copper oxychloride at the rate of 7.5g per litre of water.

Spray the tree just before bud burst, when the buds look plump, similar to what I look like after eating many pappadums. Always do a follow-up spray one week after the first as the buds will open up at different times. It will be too late to spray once the leaves have emerged and they are already crinkly.

Remember, if it rains you will need to re-spray.