How Not to Submit Plant Samples for Diagnosis

When hay stands, field crops, or even garden plants begin to show symptoms of a problem, panic may set in. The two things on everyone’s mind: what is the cause of the problem and what can be done about it? Since disease is often the prime suspect, the first step is to contact the county extension office. An agent can then assist in preparing a sample to submit to a University of Kentucky Plant Disease Diagnostic Laboratory.

Avoiding common sample submission errors can result in more timely and accurate diagnoses.

  1. Avoid packaging in sealed plastic bags, which promote decay; no diagnosis can be determined from rotted material. Wrap in newspaper and with extra padding to avoid damage during shipping.
  2. Samples submitted with little or no packing material are often further damaged during shipping. Differentiation between symptoms and shipping damage can complicate diagnosis. Wrap rootballs in a plastic bag, leaving leaves and stems exposed; this also keeps foliage from becoming contaminated with soil from the rootball.
  3. Dead is too late. Samples that contain only dead material are often impossible to accurately diagnose. The best samples include dead, dying, and healthy plant tissues. Also include details about the plants, planting site, and symptoms. This can be as important as the physical material collected.

~ KY Pest News, July 2018.