Picture of plant samples being submitted for diagnoses Kyle Broderick.
PACKAGE IT RIGHT: Samples that are too wet (left) or too dry (middle) obscure symptom expression and make disease difficult to diagnose. The sample on the right was packaged well.

Quality plant samples yield best diagnostic results

Nonspecific treatments may not control the pest causing the problem, and may harm beneficial insects.

By Kyle Broderick

Correct identification of insects and other pests, and diagnoses of diseases can help you provide effective, targeted treatment. Nonspecific treatments may not control the pest and can inadvertently harm beneficial insects, as well as waste your money.

If you have plant or insect problems, Nebraska Extension educators and the UNL Plant and Pest Diagnostic Clinic can help.

To submit samples for diagnosis, follow these simple steps. (Additional tips for submitting samples of herbaceous plants, turf, woody plants, other plants, insects and chemical injury are available at CropWatch on the Sample Submission page. 

Here’s how to provide quality samples to yield best results:

 Send several whole plants, roots and all, that represent all stages of the symptoms being expressed. Often what appears to be a leaf problem can be a root problem.

 Provide photos if available.

 Include “normal” plants from the area near the symptomatic plants for comparison.

 Enclose the root ball in a plastic bag to keep the soil from touching the leaves.

 Place entire plant sample in a plastic bag to reduce drying.

 Never add water to the bag. If the sample is excessively wet, add a dry paper towel to the bag.

 Fill out a Submission Form and include it with the sample. Provide the chemical history (current and previous year), planting date, crop growth stage, symptom description, number of affected plants, symptom distribution (low-lying areas, field entrance, strips, etc.) and field history.

 Keep samples cool and place in a sturdy container for shipping.

 Using FedEx or UPS, ship early in the week (Monday-Wednesday) to the Plant and Pest Diagnostic Clinic, 448 Plant Science Hall, Lincoln, NE 68583-0722.

Costs for services
The standard test costs $15. It involves examination with the aid of a microscope or other basic diagnostic tools. Diagnosticians will provide as accurate an identification as possible, using available resources.

Additional information and recommendations will be provided as appropriate. Every attempt will be made to return the completed Specimen Identification Form within five working days.

For specialized tests, fees are assessed in addition to the standard fee. They are:

 culture for pathogen identification (insects, fungal and bacterial pathogens), $10

 plant parasitic nematode assay (other than SCN), $40

 miscellaneous serological test (specialized fungal and bacterial tests), $10

 bacterial ID using Biolog System, $20

Each sample should include the appropriate fee (check or money order) made out to UNL Plant and Pest Diagnostic Clinic. The amount depends on the level of diagnosis desired as indicated.

Broderick is coordinator of the University of Nebraska-Lincoln Plant and Pest Diagnostic Clinic. This report comes from UNL CropWatch.

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