Plant Pathology: Extension: Plant Disease Library

How To Methods

How To Submit Samples For Plant Diseases

Holly Thornton, Homeowner IPM Specialist

Plant diagnostic clinics are operated and maintained to provide County Extension offices with diagnoses and educational programming to maximize economic input, promote environmental integrity by targeting pest control management educational efforts and improve the sustainability of agriculture in Georgia. Contact your county Extension office for submission of plant disease and plant insect samples.

CHARGES:

$25.00 fee will be charged for disease diagnosis for all Georgia samples NOT APPROVED BY THE COUNTY EXTENSION OFFICE OF SAMPLE ORIGIN.
Additionally, beginning January 1, 2007, there is now a $10 processing fee for ALL PHYSICAL HOMEOWNER samples submitted to the Homeowner IPM Plant Disease Clinic. This fee should be submitted along with the shipment of the plant sample. For more detailed information, please review the December 2006 Homeowner report (http://plantpath.caes.uga.edu/extension/documents/DECEMBER2006_Final.pdf). Any questions can be directed to Holly Thornton.

PLANT DISEASE INFORMATION FORMS:

Acquisition of complete and accurate information for the completion of the appropriate PLANT DISEASE INFORMATION FORM is essential. Particular attention to previous chemical application is stressed. Knowledge of previous control measures can aid the specialist in formulation of the most practical control recommendation.
Blue Forms are required for all commercial specimens. Commercial specimens include Greenhouse, Nursery, Golf Course, Ground Maintenance, Retail Outlet and Landscape. Extension specialists, Researchers, and Consultants are also required to completely prepare a blue form.
Yellow Forms are required for all Homeowner IPM specimens. Homeowner IPM specimens may include plant diseases for diagnosis and insects for identification.

PLANT SYMPTOMS AND SPECIMEN SELECTION:

Wilting, Yellowing or general decline. If practical, it is best to send entire plant (leaves, stems, roots). Collect plants which have early disease symptoms. Dig up carefully. DO NOT PULL UP---many roots will be lost.

Twig and Branch Blights and Cankers. Select specimens which show recent infection. Include healthy tissues with diseased tissues. DO NOT INCLUDE TWIGS, ETC. WHICH HAVE BEEN DEAD FOR SEVERAL MONTHS. THIS TYPE MATERIAL WILL NOT ALLOW PROPER IDENTIFICATION.

Foliage Diseases. Select leaves which have early and recent infections. Marginal burning of leaves should be sent. Symptoms of this type usually indicate chemical injury or some type of root disorder (physiological, organic or chemical).

Fruit and Fleshy Plant Organs. Diseases of these structures require special attention. Never select a specimen which is exhibiting advanced stages of decay or disease. Select fresh specimens which exhibit early symptoms.

SHIPPING PLANT DISEASE SPECIMENS:

Place diseased specimens in a plastic bag. DO NOT ADD ANY MOISTURE. Place a DRY paper towel in the plastic bag with the specimen. This will absorb any excess moisture. Fleshy fruit and vegetables should be wrapped separately. Paper towels are better wrappings, but brown paper and newspaper are good. KEEP ALL SPECIMENS COOL. DO NOT ALLOW SPECIMENS TO BECOME DRIED OUT AND BRITTLE.

Ship specimens Mondays, Tuesdays, Wednesdays. Samples shipped on Thursdays and Fridays usually require longer to reach the Plant Disease Clinic. This often results in complete decay or drying-out of the specimen; therefore, diagnosis is greatly hindered. Place prepared specimen in a mailing tube. If specimen is too large, put it in an appropriate sized box. Fill out as complete as possible a PLANT DISEASE INFORMATION FORM (blue) for commercial samples, HOMEOWNER IPM CLINIC form (yellow) for each specimen. Address with appropriate label and send to either the Athens or Tifton Extension Plant Disease Clinics (see chart on Plant Disease Clinics page), depending on the crop involved.

Good Samples	Bad Samples
Area showing healthy & diseased	Dried out and brittle
Sample with a dry paper towel and plastic bag	Sample sent in a moist paper towel and plastic bag
Sample with entire root system	Sample pulled up and dried out