leaf curl

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stumpy
Posts: 7
Joined: Thu Sep 03, 2009 8:32 pm
Location: spencerville, in.

leaf curl

Post by stumpy » Sat Jul 31, 2010 10:11 am

Iam having a lot of leaf curl on most of my apple varities. I am in zone 5 in Indiana. The curl is side to side and stem to the point. I've looked high and low for worms or insects but nothing! What am Im looking at here? I have only been spraying withh Imidan and captan every two to three weeks. My gala and smokehouse, yellow delious, fuji, pink lady don't seem to be affected. The braeburn, enterprise are all others are affected. Any ideas greatfully excepted!!! Thanks :idea: :idea: :idea:

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Drew Dubious
Posts: 104
Joined: Mon Jun 21, 2010 5:58 am
Location: Canton MA

Re: leaf curl

Post by Drew Dubious » Sat Jul 31, 2010 12:09 pm

I would bet on rosy apple aphids. While large numbers of any type of aphid can stunt new growth and cause sooty mold to develop on fruit and leaves, the rosy apple aphid injects a toxin with its saliva that causes the leaf to curl and the fruit to be distorted. Often these damaged leaves turn bright crimson in color. Relatively low numbers of rosy apple aphids can cause considerable damage. Other aphids such as the green apple aphid and the apple grain aphid do not curl leaves.


Examine four leaf terminals on each of 5 scaffold limbs on each tree for active aphid colonies. A 1 to 2 % application of insecticidal soap or summer horticultural oil can provide effective control of these aphids. Control of rosy apple aphid after the leaves have curled may be difficult. While effective control can be obtained with a 1 to 2% summer horticultural oil treatment, caution is advised as these may be incompatible with some other pesticides (particularly sulfur containing products), are phytotoxic at higher temperatures (above 100øF and high humidity) and at high concentrations (>2%), and may affect fruit finish on some varieties.


I have never used Imidan, I try to use natural repellants and insecticides 1st. A simple dishsoap and warm water spray will destroy the aphid colonys you find. They are also repelled by garlic. Unfortunatly, I do not believe there is any way to control it aside breaking the aphid lifecycle and manually removing infected foilage.

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