Most Asked Questions of the Week

www.utahpests.usu.edu Here are some of the answers to the most asked questions this week.  Thanks to the Utah Pests website for being such a great, reliable source for helping  us diagnose the pest problems that we see on a regular basis.  They have wonderful  pictures and up-to-date information for the homeowner. This past week we have a lot people asking about what is wrong with their peach trees.   They have lost lower limbs of their trees, the leaves came out in the early spring but now have fallen off, or the leaves are misshapen.  USU Tree Fruit IPM Pest Advisories provide nearly weekly updates on current insect and disease occurences, biology, and treatment recommendations for Utah.  Updates run  from mid-March through September. You can subscribe to their IPM advisory and receive  updates by email.   PEACHES/NECTARINES

Coryneum Blight (Shot hole) Shot hole lesions are starting to appear on leaves at this time. Shot hole (or coryneum blight) overwinters in buds and spreads from there to leaves and later in the season, to developing fruit. On the leaves, you will see small round holes that may be purplish or tan in color. The center of the lesion will sometimes still be attached. Cool, wet weather contributes to spread. At the shuck-split stage, you can use Bravo (chlorothalonil, Daconil for residential use), Abound, Captan, Ziram, or Pristine. And keep in mind that the most important treatment is an application of copper at 50% leaf drop in the fall.

Peach Leaf Curl In the past, we have seen peach leaf curl in Box Elder, Davis, and Weber counties. Peach leaf curl is a fungal-caused disease that affects peach and nectarine. We may see it again this year due to the prolonged periods of cool, wet weather we have had this spring. Damage may not be evident until later in May or early June. Infection occurs just as the leaves are opening, and causes puckering and distortion of the leaves. The affected area is pink at first, and then turns green, then brown. Leaves will drop. After the initial infections, new ones only occur when temperatures are below 79 F. If you see these infections, note that there are no fungicides that can be applied at this time. The best treatment is a single application of a fixed copper applied at leaf fall. For now, maintain tree vigor of infested trees by thinning more fruit than normal, reducing drought stress with irrigation, and applying extra nitrogen fertilizer.