Oak Wilt season is rapidly approaching! We have already seen several submissions here at the Texas Plant Disease Diagnostic Lab. However, we have seen a few submissions that weren’t adequate for Oak Wilt testing. Here are a few pointers on how to correctly take samples from your oak tree:
1. We need branches that are about 6 inches long and 1 to 2 inches in diameter. We can’t do anything with twigs! Ideally, the branches you send should be from the part of the tree that is showing symptoms of decline.
2. If you can, send some symptomatic leaves. While we don’t use the leaves in the actual assay, they are a useful diagnostic tool. The leaves of an oak tree that is infected with Oak Wilt will display symptoms that can help us in the initial stages of diagnosing (see below).
3. Keep the sample cold! You can buy the cheap styrofoam coolers to use in shipping. Throw in a small ice pack too, the kind you would put in a lunch box. Don’t send expensive coolers! (you won’t get them back!)
4. In accordance with #3, try not to let your sample sit in the back of the truck, on your back porch, or anywhere in open air where it could dry out and/or get too hot. The Oak Wilt fungus can’t survive hot weather, and it makes it harder for us to recover the pathogen and give you a correct diagnosis.
5. Send in the submission form along with your sample, but put it in a plastic bag. We don’t like soggy, dirty submission forms.
For more information, watch our video on how to correctly package your sample for submission. Also, detailed instructions on how to sample for an Oak Wilt test are listed on the second page of your submission form.