The accuracy of the laboratory assay is contingent upon the quality of the specimen submitted. Tissue that is too small, of the wrong type, desiccated, necrotic, or dead may contain too little viable vascular tissue or be contaminated with pathogens that will interfere with the isolation of the oak wilt fungus. Tissues selected from parts of the tree without good foliar symptoms may not be infected or sufficiently infected to produce a positive assay result. The current turnaround time for Oak Wilt is a minimum of 3 weeks due to the amount of time the fungus needs to grow on specialized media.
OAK WILT or DED (Dutch Elm Disease) sampling:
- Collect branches 1 inch to 2 inches in diameter showing symptomatic leaves.
- When possible, enclose twigs with symptomatic leaves still attached in a separate plastic bag.
- Place the plastic bags in a Styrofoam ice chest with ice packs—DO NOT SEND ON DRY ICE OR WITH ICE IN PLASTIC BAGS.
- Ship samples by overnight delivery to help ensure an accurate diagnosis.
- Complete the Plant Disease Diagnostic Form (D-1178). We encourage you to include recent pesticide history (last 3 weeks) and any other pertinent information. Please put the check and form(s) in the box and the sample.
- Ensure the identification on the form matches the labels on the sample bags.
- Keep the completed form in a separate plastic bag from the specimen. Limit 1 (one) sample per form.
- Package all specimens securely to prevent damage during transit. Cardboard boxes usually help prevent crushing. Add packing material such as newspaper to prevent specimen damage during shipment.
- Ship samples to the above address by overnight delivery or mail early in the week to ensure fast delivery. Plant samples often decompose if left over the weekend in a delivery warehouse. Same-day or next-day service is recommended.
- Obtain one of the submission forms (D1178) from our website, complete it, and send it in with your sample.
- Oak Wilt Sampling video
