Instructions for Sample Collection and Submisson

Sample Collection and Submission

  • Carefully inspect your plants to accurately assess symptoms and distribution. Complete the sample submission form with detailed information on problem, symptoms, disease distribution, plant parts affected.
  • Collect a representative plant sample(s) that represents the symptoms and signs observed. Plant samples should be freshly collected.
  • Submit a generous amount of plant material, including a mixture of symptomatic and asymptomatic tissue. Do not send dried or death plants.
  • For root and vascular problems, carefully dig out the plant to preserve the root system. Remove excess soil and wrap the roots with dry paper towels.
  • Place the sample in a plastic bag (Ziploc bag), seal, and maintain samples fresh or refrigerated after collection until they are submitted to the MDL.
  • Leaf, fruit or vegetables samples should be placed in sealed bags, without being wrapped in paper towels.
  • Do not mix samples from different plant species in the same submission bag. Label each sample clearly.
  • If samples are hand-delivered directly to the lab, they can be sealed in plastic bags as described above. Alternatively, place the samples in a box and mail them to the MDL. Do not send samples in envelopes.
  • Use the next-day or two-day shipping option. It is important for the sample to arrive within 48 hours of collection. All samples must be accompanied by a completed sample submission form.
  • Mail samples early in the week to avoid the weekend layover in the post office.

Digital Images Submission – Optional

Please send relevant digital images to . Include the submitter name and plant sample in the subject line (Example: John Smith-cotton) and clear photos of plant specimen, plant tissue damage, location where it was seen, and distribution of symptoms/problem.

Specific Instructions for Citrus Greening Testing

Note: The bacterium causing citrus greening is not uniformly distributed in the tree, hence a good sample to submit would be 3-4 small twigs from different parts of the tree, each with 4-5 symptomatic leaves. Please follow the instruction above to send the sample.

Specific Instructions for Xylella Testing

Note: The bacteria are not evenly distributed throughout the vine or shrub; therefore, false negative results may occur if samples are not taken from symptomatic plant parts. Symptomatic leaves that still contain some green tissue and are attached to the canes generally give the most reliable test results.

  • Blueberries – send multiple leaves/petioles attached to a stem with scorch symptoms (similar to citrus greening samples)
  • Peach – root samples
  • Pecan – multiple leaflets attached to a stem with scorch symptoms
  • Shade tree species – multiple leaves/petioles attached to a stem with scorch symptoms (similar to citrus greening samples)