Leaf Blister Issues on Trees
Weather conditions this year appear to be just right for a large number of “leaf blistering” diseases to show up. For growers of peaches and other stone fruits, this includes leaf curl, a fungal disease that can cause premature leaf drop and reduced yield. While there are treatments available for control of this disease, it must be done well in advance. In other words, it is too late to treat for the symptoms you are seeing now. If in fact, you do suffer significant losses of your crop this season, please see OSU Fact Sheet EPP#7639 Leaf Curl of Peaches and Nectarines for instructions on preventing an outbreak next season.
These same leaf problems can also show up on a variety of landscape ornamentals, including many tree and shrub species. While unsightly, these blemishes are not going to cause the plant any significant harm and attempts at treatment are not recommended. About the best you can do as a homeowner is to help minimize additional stress on the plant to minimize premature leaf drop. The best way to do that is to make sure the plant does not undergo severe drought stress or other factors under our control (such as poor pruning or root disruption).
In cases of severe infestation for a prized tree, it could be helpful to collect the leaves in the fall and remove them from the area, although as you can imagine, that is likely only helpful in certain unique situations.
The take home message today is to remind you once again not grab the sprayer and spray “just in case” every time you see a plant with a possible issue. As you can see in the leaf curl example, it is not only important to be able to properly identify the problem, we must also understand enough about the problem to know when to treat.
For more information of this or any other horticultural topic, you can contact Keith Reed, the Horticulturist in the Payne County Extension office. Keith can be reached via email at firstname.lastname@example.org, phone at 405-747-8320, or in person at the Payne County Extension office, located at 315 W. 6th in Stillwater.
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