Clinic Update: Mid-Summer Samples Submitted to the Diagnostic Clinic

Mid-summer has been a busy time for the Diagnostic Clinic with many samples submitted for diagnosis.

Potato with common scab. Photo by Simeon Wright

We have received redbuds, oaks, and other trees with general decline symptoms. Many of these trees have a leaf scorch, probably related to hot dry weather. We have also received dogwood samples with leaf scorch, especially newly planted dogwoods and those in exposed locations. We have received a maple and several shrub samples with growth regulator injury symptoms that are consistent with dicamba, cloropyralid or phenoxy herbicide injury. We continue to receive samples from callery pears with fireblight symptoms. We have also received some shrub and tree samples that appear to have been over watered. It is important to water carefully during the drought to prevent over or under watering. With many of these tree and shrub samples, it is helpful to have more than a small branch from the plant. If there is a serious problem affecting the plant it often originates in the trunk or roots below the point where a sample was collected and submitted to the diagnostic clinic. You can call us if you have questions about what to submit for diagnosis.

We have not received a lot of ornamental plant samples other than woody shrubs and trees. We had a Purple Wave petunia sample with severe iron chlorosis symptoms found in high pH soil. The wave series of petunia is reported to be more sensitive than many other varieties.

We have had a few vegetable samples. We have had tomato samples with bacterial spot, fusarium wilt, blossom end rot and early blight. We also had a pepper plant with sunscald affecting the fruit, and a potato sample with common scab.

Among fruit samples, we have received apples with freeze injuries related to the cold weather last spring. An elderberry sample had a bacterial leafspot. In addition, we have received grapes with black rot as well as grape berry moth damage.

We look forward to receiving your samples. Please refer to the sample submission section of our website for more information on sample submission.

Simeon Wright and Sandra Davis,
Plant Diagnostic Clinic
573-882-3019