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Instructions for Completing the Plant Disease Diagnostic Form (#450-097)


450-097-A (SPES-512NP)

Authors as Published

Authored by Lina Rodriguez Salamanca, Instructor, Diagnostician, and Manager, Plant Disease Clinic, School of Plant and Environmental Sciences, Virginia Tech; and Elizabeth Bush, Extension Plant Pathologist, School of Plant and Environmental Science, Virginia Tech

The Plant Disease Diagnostic Form was designed to accommodate a wide variety of plants and growing situations; therefore, certain entries on this form may not be appropriate for a particular specimen or situation. Much of the information requested helps reconstruct the "field situation" for the diagnostician. Consider each section of the form carefully; the information provides important clues to the diagnostician that are significant in guiding the diagnostic process and formulating the control recommendation. Your local Extension office staff can assist you in completing the form and include the relevant information requested on the form, so when possible, complete the form with the assistance of your local VCE agent or VCE staff member.

  1. Provide the date the sample was collected.
  2. Plant cultivars/varieties can differ in their response to plant pathogens and environmental conditions, so try to include this additional information, along with the plant name.
  3. Select the first checkbox if the submitter is not a VCE agent/staff and the second box if the submitter is an Extension agent or staff. List the name of the submitter, email, and phone. If no agent/staff or email is listed, the diagnostic report cannot be sent to the VCE office, and the relevant VCE personnel cannot assist the client.
  4. List the name of the grower and the grower email (if no grower email is provided the Plant Clinic will not send an electronic report to the grower). Include the county where the plant originated from. The address is useful, particularly if a hardcopy report needs to be mailed by the Extension office, and it can also be useful for the diagnostic process. The grower's area code and phone number are often useful if the diagnostician or Extension agent/staff needs to contact the grower for additional information.
  5. Please detail 
    1. the problem and/or concern clearly and 
    2. describe the symptoms observed in detail. This is critical because 
      1. a sample that is shipped may no longer display the symptoms you observe and 
      2. you may be able to see details about the pattern of the problem on the plant(s) or within the planting that the diagnostician cannot see on the sample submitted. Note: Statements such as, "Please diagnose the problem.", “Why is my plant dying?”, “How can I save this [plant]?” are not useful for the diagnostic process.
  6. Check the appropriate selections so that the diagnostician is able to provide an appropriate control recommendation. 6A: Select the plant location/production setting. (6B) Select the production system/approach.
  7. Check the appropriate boxes under each of the four fields (plant part affected, general appearance, disease distribution, and location).
  8. Include the date the symptoms were first noticed and check the appropriate box.
  9. An estimate of the total planting size/number of plants is very helpful for guiding the diagnostic process and providing an appropriate management recommendation.
  10. The percentage and/or number of plants affected provides critical information on the extent of the problem.
  11. List last year's and next year’s crop, if applicable (e.g., field crops, vegetable garden).
  12. Knowledge of past weather conditions and irrigation information helps to determine whether an abiotic problem may be involved.
  13. Check the appropriate boxes under each of the five fields in this section to detail the soil characteristics.
  14. List the date of the last soil test.
  15. Fertilizer, pesticide, and growth regulator application history is important information for identifying certain problems. For this information to be of value, each chemical's specific common name and/or brand name needs to be listed, in addition to the rate and date of application for each fertilizer/pesticide/growth regulator listed.
  16. This section is only necessary for woody plants, such as trees (including fruit trees), shrubs, woody ground covers, and vines (including grapevines). If applicable, please take the time to complete this section.
  17. Include any additional details and observations in this box.

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Publication Date

September 2, 2023