Plant Disorders and Special Tests for Plant Diseases

Plant Disease or Disorder Specimens
  1. Select material showing the symptoms in question. Send several samples in different stages of the disease or disorder development. Be generous; however, do not send totally rotten, dead, or decayed material, or material which has been dead a long time.
  2. Send entire plant(s) including roots. Dig, do not pull, plants from the ground. The roots should be intact. Remove excess soil from the roots with gentle shaking. Do not wet the leaves or stems. Wrap the roots so that soil clinging to the roots will not be loose in the package. Do not ship wet plants.
  3. When entire plant(s) cannot be sent (large trees or shrubs), send a sample of the symptoms in question and a root sample, at least one pint, including feeder roots.
    • Pictures are helpful. Photographs (or digital images) should show the whole plant in question, and closeups of the symptoms and of the trunk and base of the plant(s).
  4. When only local parts of plants are affected (leaf spots, stem cankers, or swellings), send several affected parts. Stem and branch sections should include a short section of the healthy tissue so that the transition area between affected and unaffected parts is shown.
  5. Fruits and vegetables should be wrapped individually in dry newspaper and shipped in a suitable box.
  6. Provide information concerning the sample on a PPDC Specimen Form or in a letter. Be sure to include the plant or crop name, any previous plants or crops at the same location and when, description of the symptoms (when they started and how it spread), number of plants affected, and history of the plants(water, fertilizer, fungicide, and pesticide regimens).
  7. The CWEPPDC will charge a fee for its diagnosis. Expect to receive a bill if payment is not included with the sample.
  8. Ship samples to the following address.
  9. Under some circumstances, very specific diagnostic procedures are required for accurate diagnosis. To review these tests and their associated fees, click here.


Bad - Completely alive plants
Bad - Completely dead plants
Good - Branch showing transition from living to dying parts

Special Tests for Plant Diseases

In some cicumstances, very specific tests are required for accurate diagnosis. These tests are described below.


TESTSERVICE FEE
Plant Virus Test Using ELISA $ 20
Plant Virus Test Using dsRNA $ 35
Bacterial Wilt of Geranium Using ELISA $ 35
Phytophthora Using ELISA $ 40
Bacterial Identification Using Fatty Acid Analysis $ 35

Click on the test above to see its description



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Special Test Descriptions

ELISA
  • ELISA is an acronym for enzyme-linked immunosorbent assay and utilizes antibodies specific to the pathogen in question.
  • An ELISA test is a specific diagnostic test. Different ELISA procedures are used for detecting selected viral, bacterial, or fungal pathogens.
  • The CWEPPDC can test for impatiens necrotic spot virus (INSV), tomato spotted wilt virus (TSWV), Phytophthora (fungus) and bacterial blightt of geranium (bacteria).
  • Extensive ELISA tests for viruses other than INSV or TSWV will require higher fees and are usually discussed by telephone before being undertaken.

dsRNA analysis
  • dsRNA is an acronym for double-stranded ribonucleic acid.
  • This test allows for the detection of a large number of viruses which utilize RNA as their replicative form. Not all plant viruses are RNA viruses.

Fatty Acid Analysis
  • Fatty acid analysis is used to identify bacteria which have been isolated from plant material.
  • Fatty acid analysis allows for the identification of many bacteria. It requires seperate procedures for each bacterial isolate.
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