Peach tree disease

Asked June 6, 2016, 11:35 PM EDT

See pictures below. These are from my peach tree in elkhorn Wisconsin. What disease is it and does the spray below kill it?

Walworth County Wisconsin peaches peach trees

3 Responses

The disease is known as "peach leaf curl". It is most commonly seen on the first leaves to emerge in the spring and is also found to a lesser degree on fruit. The fungus causing peach leaf curl overwinters on the exterior of the buds. Once bud scales start to separate in early spring, the fungus invades and control from that point on is very difficult to impossible to achieve - especially for non-commercial orchardists. Only the earliest leaves to emerge will be infected. Leaves appearing later in spring will be clean. However, loss of activity in these first-formed leaves will have detrimental results in tree growth and fruiting throughout the season.

Captan, the sole fungicide listed on the label you sent is not effective in control for peach leaf curl, although orchards that received captan in cover sprays of the previous years are less apt to be affected by leaf curl.

Several formulations of copper (Kocide 2000, Kocide 3000. C-O-C-S WDG, Cuprofix Ultra 40 Disperss or Nordox 75 WG are listed for dormant application and will help in control of bacterial spot as well.

For leaf curl alone, various formulation of chlorothalanil, Ziram and Thiram will have activity on leaf curl, but not much impact on fruit infection. Immunox, a common fruit spray for noon-commercial orchards, does contain chlorothalanil and should be readily available.

To achieve control, sprays need to be applied during dormancy, from the point where trees enter dormancy in late fall up to the point where bud swell begins. Where infections have been severe, 2 sprays are recommended - one in late fall and the second in late winter prior to bud swell.

Be sure to follow label recommendations for timing and rates.

Thank you very much for the info!
I looked up spectracide immunox and it says active ingredients are myclobutanil 1.55% and ethyl-3-ethoxypropionate 4.25 % not cholothalanil. Is that still ok to use? and i wait until leaf drop this fall to use?
thank you
mark brower

Mark,

Thanks for the comment. Also, thanks for pointing out my error in regards to Immunox. It is still the best option for non-commercial growers. Unfortunately, some of the strongest performers in control f this disease are no longer available to us.