Case Details
Curling leaves on apple tree
Submitted by Kerri Ison on 9/17/2009
Hazen variety apple tree has leaves curling on upper 25% of tree. Trees was planted in the fall about 2.5 years ago in the fall and were about 5 ft tall. Soil is 80% clay/20% sandy soil and receives full sun. Tree is watered regularly. Applied Scott's weed-n-feed on lawn but very little around trees. Other apple trees are unaffected. Any idea what is causing leaves to curl?
Reply by Unknown on 9/17/2009
The weed and feed could still be the culprit. It can volatalize and form a "cloud" that can float into just the right place and damage plants--especially on foggy, humid days. This tree may be more sensitive, or the cloud drifted into just the right place. Also, new leaves seem to be more susceptible and show symptoms, and the younger growth is probably at the top of the tree.
Reply by Jed Colquhoun on 9/21/2009
We respectfully disagree with the answer above. The symptoms on this apple tree, particularly the brown lesions, are not indicative of synthetic auxin herbicide damage from the active ingredients included in typical weed and feed products. Moreover, recent cool weather conditions do not favor herbicide volatility. While synthetic auxin herbicides can cause symptoms to the foliage on trees (e.g. rolling, cupping, and other deformities), injury is most common from spray particle drift. Volatility is less likely to cause significant symptoms and exposure is more likely from sprayed applications than weed-n-feed applications. Since there are brown lesions on several of this tree's leaves, it is quite possible that there is another cause of the curling observed on the leaves. Jed Colquhoun and Chris Boerboom
