Answer: Peach leaf curl is a fungal infection; an insect killer would not control a fungal infection. It is impossible to control this once it has appeared for the season. It must be controlled before it appears. It is controlled by treating either in late fall or early spring. So you should not be treating for it in midsummer. Here is more detailed information about it.
Please check with your local county extension as to what product to use and how/when is best to apply it in your local area. Also, read the entire label and follow the directions on it carefully and completely.
Some sprays will damage foliage if applied at a high temperature, at the wrong time of year, or on a plant that is not listed on the label. Always make sure the product you are using is intended to control the specific problem and is listed for use on the specific plant you want to treat. Apart from risking damaging your plant, "the label is the law" and to apply something outside the label directions is illegal.
Peach trees may ooze wherever there is damage to the trunk such as from a weedwhacker or borer infestation.
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