Plant Disease and Insect Diagnostic Laboratory
Whether it's your pine tree that is looking sick or your wheat crop that is stunted and yellow in low-lying areas, we are here to help solve your plant disease problems.
The primary goal of the Plant Disease and Insect Diagnostic Laboratory (PDIDL) is to provide residents in the State of Oklahoma with both accurate diagnoses of plant diseases and insect pests and recommendations for their control. The PDIDL operates throughout the year to provide plant disease and insect identification services to extension agents, individuals, consultants, and commercial producers. To see how receive a diagnosis, refer to the section on "Sample Collection". To request service please fill out a Plant Disease or Insect Diagnostic Request Form.
The mission of the Oklahoma Cooperative Extension Service is to disseminate and encourage the adaptation of research-generated knowledge relating to agriculture, home economics, rural development, and 4-H youth development to the residents of Oklahoma.
- What is the PDIDL?
Whether it's your pine tree that is looking sick or your wheat crop that is stunted and yellow in low-lying areas, we are here to help solve your plant disease problems.
The primary goal of the Plant Disease and Insect Diagnostic Laboratory (PDIDL) is to provide residents in the State of Oklahoma with both accurate diagnoses of plant diseases and insect pests and recommendations for their control. The PDIDL operates throughout the year to provide plant disease and insect identification services to extension agents, individuals, consultants, and commercial producers. To see how receive a diagnosis, refer to the section on "Sample Collection" below.
The mission of the Oklahoma Cooperative Extension Service is to disseminate and encourage the adaptation of research-generated knowledge relating to agriculture, home economics, rural development, and 4-H youth development to the residents of Oklahoma.
- Services
The PDIDL strives to provide both accurate and timely diagnosis of the samples received. It is critical to complete the Plant Disease or Insect Diagnostic Request Form with as much information as possible. Inadequate information is the primary reason why we cannot identify plant problems or arthropods.
Home gardeners should always submit samples (images or physical samples) through their local county extension office. Commercial clients may submit through the county extension office or contact the lab directly.
Sample information is reviewed and samples are examined by our diagnosticians. Plant disease problems are diagnosed based on symptoms, and specialized testing may be required. Insect identifications are generally based on morphology of the insect or particular pattern of damage observed. Diagnostic reports are generally sent by email.
It should be noted that at least 50% of plant problems are due to environmental factors or improper plant care rather than infectious diseases. However, secondary pests and pathogens may invade plants that are weakened or stressed.
Services Available
- Diagnosis of most infectious plant diseases.
- Isolation and identification of plant parasitic nematodes from soil.
- Isolation and identification of plant parasitic nematodes from roots.
- Determination of the disease problem and recommendations for its management.
- Identification of collected arthropods or plants with suspected arthropod problems.
- Check out this PDF for a more detailed list of services.
Service Fees Per Sample
At this time, Oklahoma residents can submit up to 10 samples per year for no charge. Individuals and home gardeners are reminded to submit samples through their county extension office. If a client submits more than 10 samples in a year, fees will be assessed.
The PDIDL can only provide diagnostic services for residential turf. A separate Turfgrass Diagnostic Laboratory is available for commercial turf clients.
Our lab is permitted to receive out-of-state samples for plant disease and insect diagnostics. The fees for out-of-state clients are available on this PDF. All out-of-state samples should be submitted in double, sealed plastic bags. Fees should be paid by check or money order written to Oklahoma State University. At this time, the lab does not accept credit card payments.
Services Not Provided
- Identification of molds or bacteria in soil, water, or air.
- Identification or isolation of plant pathogens from soil, water, or air.
- Positive identification of certain bacteria and viruses.
- Identification or screening for pesticide resistant plant pathogens.
- Identification of strain, race, mating type, pathovar or Anastomosis Group of pathogens.
- Isolation or identification of human or animal pathogens.
- Disease identification from dead or decomposing plants (with a few exceptions).
- Pesticide residue determinations.
- Plant tissue or soil nutrient analysis.
- Species identification of most pathogen isolates.
- Mushroom identification.
- Plant Identification.
- Plant Identification Resources: Guidelines for Plant ID & OSU Plant ID
- Sample Submission
Submitting Plant Samples
It can be difficult to grow high quality plant material in Oklahoma. The Oklahoma State University Cooperative Extension Service has an office in every county with educators that are a great resource for diagnosing a plant problem or identifying an insect. They will ask questions to help determine possible problem(s) such as site alterations, fertilizer or pesticide use, and cultural practices. About half the time, plant problems are not caused by pests or disease. Rather, they are caused by environmental and cultural practices that influence growth of the plant.
In situations where the extension educators are unable to identify the insect or plant problem, or if confirmatory testing is needed, the educator will forward the sample to specialists in the PDIDL. It is important to work in collaboration with county extension educators, but the PDIDL is available to provide expert advice and diagnostic services when pest or disease testing services are needed.
This is a summary of how to submit a high quality sample to the PDIDL for disease testing or insect identification. The PDIDL examines a large number of hosts including fruit crops, vegetables, field crops, residential turf, and ornamental plants. If you are planning to submit a sample, please review the steps below so that you collect and package the material properly.
Digital Diagnostics
Whenever possible, submit digital images for examination.
- Images should be taken on-site, before you collect a physical sample.
- Include closer and more distant views that accurately capture the problem or pest.
- Include a size reference whenever possible and confirm that your images are in focus and have good resolution. If they are blurry, too dark, or too small, we will not be able to provide a diagnosis.
Images should be emailed or taken to your county extension educator.
- For a directory of Oklahoma extension offices, look in your local phone book or visit the OSU Extension website.
- Include your contact information with the email message.
- Be sure to include additional information that describes the problem, planting date or age of plant, name of plant, variety/cultivar, patterns, chemical or fertilizer used, when symptoms were first noted, etc.
Images are generally examined on business days and replies are generally given within 48 hours.
- There may be delays during the busy season or if there is a high sample volume.
- In many cases, the county educators can identify the insect or plant problem.
- If assistance is needed, the educator will refer the case to the PDIDL.
Do not collect physical samples unless directed.
- Digital images are often adequate for diagnosis and management.
- If a physical sample is requested, the specialist may request a specific type of sample.
- It is suggested to follow the tips below when collecting and packing a sample that will examined in the lab.
Collection and Packaging
Please review the following steps for collection before you collect and package the sample.
- Collect fresh samples. The PDIDL examines field crops, vegetables, fruits, ornamental and landscape plants, greenhouse plants, residential turf, and insects found both indoors and outdoors. Commercial turf (golf courses, sod farms, athletic fields) samples should be submitted to the Turf Diagnostic Laboratory.
- Whenever possible, submit a generous amount of material or insects (Figures 1a and 1b). Include early and later symptoms
of disease.
Figure 1b. Whenever possible, include more than one arthropod for examination- Wrap foliage in newspaper or dry paper towels. If the problem is restricted to the foliage, it is acceptable to include only foliar portions of the sample (Figure 2). If submitting branches, they may be labeled and cut into smaller segments. Place samples wrapped in newspaper or dry paper towels inside a plastic bag and seal it. Never add moisture to the bag.
Figure 2. This problem is limited to the leaves and branches, so only foliage was submitted for testing- If the problem is expressed over much of the plant, it may be in the larger limbs, stem, or roots. Whenever possible, submit entire plant(s) for testing.
- Never submit samples that are dead or nearly dead.
- Remove plants from the soil with a shovel and gently shake or tap the roots to remove excess soil. Place root ball in a plastic bag and seal at the soil-line. Soil or potting mix should never contact the foliage during shipment (Figures 3 a and 3 b).
Figure 3a. When plants are wet or covered in potting mix, they cannot be tested by the lab.
Figure 3b. Wrap roots and potting mix in plastic wrap or bags. This prevents soil from contaminating the leaves.- For field crops, include multiple samples from different areas of the field in varying stages of decline. Wrap foliage in newspaper or dry paper towels and place entire sample inside a plastic bag and seal.
- Insect samples should be submitted so they are intact (not broken or crushed). Place insects in a crush proof container. Do not tape insects to paper or place them loose in a container. Gently place the insect(s) into a vial (i.e. empty pill bottle) and cushion with cotton balls or clean tissues.
- Complete a sample submission form. Include as much information as possible. Provide additional information on a supplemental sheet if necessary.
- If submitting insects, be sure to indicate where the insect was collected (soybean field, vegetable garden, bathroom, kitchen).
- Samples coming from outside Oklahoma should be placed inside double, sealed plastic bags. This helps prevent escape of pathogens or pests during shipment.
- At this time, there is no charge for Oklahoma residents to submit samples to the PDIDL. There are fees for samples originating outside Oklahoma. Out of state clients should contact the PDIDL to arrange payment prior to shipping.
Shipping samples
- Ship plants in a sturdy container immediately after collection.
- If you hold the sample, it should be refrigerated for a short period (less than 3 days).
- We do not receive packages over the weekend, so ship early in the week so it arrives on a weekday.
- Clients are encouraged to ship so that samples are delivered quickly. If shipping is delayed, the samples may be in poor condition and accurate diagnosis may not be possible.
- Ship samples to:
PDIDL
127 NRC
ENTO/PLP, OSU
Stillwater, OK 74078
Diagnostic Process
All packages are delivered to Central Mailing. Packages that arrive late in the day may not be delivered to the PDIDL until the next day. Once we receive your sample, it will be logged into the Plant Diagnostic Information System. If you have supplied an email address, we will send an email notifying you that the sample has been received.
On average, the diagnosticians examine the sample within 3 business days. In most cases, the diagnostician will send email when they examine the sample. This may be the final report with the diagnosis or a plan of work if advanced testing is needed. Some problems can be diagnosed with only microscopic examination. Other problems may require culture analysis or specialized testing that can take several weeks.
Once diagnosis is complete, the final report will be sent by email. If you have not supplied an email address, the report will be sent to the county extension educator. Information on management may be included in the report, in attached fact sheets or links for more information. The county extension educator will provide additional guidance on management, if it is needed.
- Plant Disease or Insect Diagnostic Request Form
Before sending samples to the PDIDL, please fill out aPlant Disease or Insect Diagnostic Request Form.
