Clinic Update: Spring Samples Submitted to the Plant Diagnostic Clinic

Spring is progressing rapidly, and we are beginning to see more samples in the extension plant diagnostic clinic. What follows is a description of what we have received in the past several weeks.

Many of our samples this year have been from trees. There have been a lot of samples from various conifers. Many of these samples appear to be weather related injuries associated with the drought and winter temperature fluctuations. It is important to remember that it is difficult to diagnose from completely dead, dried out branches. When possible, select branches that show symptoms but have not completely died. In some cases it is helpful to submit root material as well. You can contact the clinic for instructions on what to submit for various types of problems. The clinic has also received samples of Diplodia tip blight on Austrian pine, pine wilt nematode on Scott’s pine, Kabatina tip blight and cedar apple rust on juniper, Rhizosphaera needlecast on spruce, and Armillaria root rot on arborvitae.

Cedar apple rust. Photo by Simeon Wright

We have also received several greenhouse samples. From lettuce we have had samples with Rhizoctonia root and stem rot, and Sclerotinia drop (white mold). We have had Rhizoctonia stem rot on tomato as well as phytotoxicity from chemical applications to tomatoes, impatiens and geraniums.

Finally we have received some insect samples. A rhododendron sample with deformed growth was infested with aphids. From structures we have received samples of carpet beetles, hackberry psyllids, blowfly pupae and acrobat ants.

We look forward to receiving your samples. Not only does an accurate diagnosis allow you to manage your plant problems, your samples also allow us to see what’s happening around the state. Please refer to the sample submission section of our Website, http://soilplantlab.missouri.edu/plant/index.htm, or contact us for more information on sample submission.

Simeon Wright
573-882-3019