The plant doctor

Examples of foliage and fruit samples that Karen Flint Ward has received for diagnosis. (Courtesy Karen Flint Ward)

See something unusual going on with the leaves in your orchard? Or maybe in the clusters in your vineyard? Help is not far away, says Karen Flint Ward of Washington State University’s Plant Pest Diagnostic Clinic.

Ward, who runs WSU’s plant clinic in Pullman, is a resource for growers who encounter the unusual in their field. If there were general practitioners for plants, she’d be like a family doctor for plants.

Working with samples sent by growers, her clinic offers diagnosis of plant diseases and disorders, insect and arthropod identification, and plant and weed identification. Like a family doctor, she’s not a specialist
in all things. But she knows where the specialists are and where to send samples for diagnosis beyond her expertise.

Diagnoses

Ward has been the Pullman clinic diagnostician since 2010 when WSU created a new lab in Pullman. Previously, the university conducted plant diagnosis at its Prosser research station, but that lab closed. Ward received her master’s in plant pathology from University of California, Davis, and worked as diagnostician at Utah State University. While in California and Utah, she worked with tree fruit and grapes.

“I want the tree fruit and grape growers to know that I’m here to help,” Ward told Good Fruit Grower. “I’m only an overnight Fed Ex away.”

What problems can she diagnose? Ward can identify pathogens like phytophora, bacterial canker, and crown gall. She uses visual examination, pathogen culturing, and pathogen-specific tests to identify problems. Samples needing molecular testing are sent out to another lab. Insect and weed samples are forwarded to specialists for identification.

Ward coordinates with WSU’s tree fruit and grape virus experts at Prosser, Drs. Ken Eastwell and Naidu Rayapati, on viruses. The Prosser research station houses the Clean Plant Center Northwest for fruit trees, grapevines, and hop plants and has advanced technologies to diagnose virus and viruslike diseases.

Determining the cause of symptoms like yellowing leaves or pockmarked fruit is not always straightforward. Often, nutritional deficiencies can mimic diseases. “A lot of times, the disease or disorder is not that obvious,” she said. Ward can determine if the problem is pathogenic or nutritional. If it’s nutritional, she will recommend the grower send samples to a lab doing plant nutrient analysis.

Last year, she received a sample of strange-looking stone fruit and determined the disorder was related to weather and not a disease. “I see as many disorders on tree fruit as I do diseases,” Ward said.
After receiving a sample, Ward will talk to the grower about what’s happening in the field to give her ­background on the problem.

Turnaround time varies greatly, depending on whether she can identify the problem in her lab or must send samples out for further testing. “I always try to keep the grower informed with what’s happening and the time involved,” she said, adding that she stays in contact with growers through phone and e-mail. Growers receive a written diagnosis of the problem.

In 2013, her lab received around 150 samples, a number she wants to increase. Because of her proximity to the state’s wheat-growing region, most of the samples she processes are small grains.
Ward wants to the tree fruit and grape industries to know that she’s available as a resource.

How to send a sample

Collect several samples showing symptoms of concern in various stages of the problem, especially the early stages. Include fruit, roots, and a soil sample. Don’t submit dead, dry, or decayed samples because they can’t be accurately diagnosed. Place the samples in a sturdy box, putting soil, branches, and leaves in a plastic bag, and wrap fleshy plant material like fruit in newspaper.

For insect identification, freeze insects first before packing gently with tissues or cotton in vial. Do not send live insects or those trapped on a sticky card.

Provide grower contact information and detailed information about the problem, the plant, and cultural care. When was the problem first observed? Is it spreading? How old is the plant? Cultural information includes site description (drainage, exposure, weather), irrigation, and pesticide and fertilizer use.

The costs for insect identification and plant problem diagnoses are $25. For plant diagnoses involving pathogen culturing, the fee is $40. •