Washington’s apple industry has saved millions of dollars by following Tim Smith’s advice to fumigate the ground before replanting.  (Geraldine Warner/Good Fruit Grower)

Washington’s apple industry has saved millions of dollars by following Tim Smith’s advice to fumigate the ground before replanting. (Geraldine Warner/Good Fruit Grower)

Applied research projects that Washington State University extension educator Tim Smith has worked on have returned billions of dollars to the state’s tree fruit industry.

For example, in the 1980s, when Smith joined Extension, it was known that when an orchard was replanted, the trees didn’t grow as well as a new orchard on virgin ground. The standard practice was to dig a planting hole 18 to 22 inches wide and 3 feet deep and put new soil in it, but trees still struggled to grow and crop.

It had already been discovered that fumigation could overcome replant disease. Smith’s accomplishment was in convincing the industry to use it. He did trials showing that broadcast fumigation of the ground before planting could dramatically improve the growth and productivity of a new orchard.

He estimates that fumigation can boost yields by a third and notes that the additional yield is all money back in the grower’s pockets, assuming the other two-thirds have covered growing costs.

He estimates that in the past 30 years, 60,000 to 70,000 acres of orchard have been planted in fumigated ground, representing an additional $1.8 billion return to growers. About 65 percent of the acreage being replanted nowadays is fumigated, up from only 5 percent three decades ago.

Fire blight

Another major focus of Smith’s work has been the pear and apple disease fire blight. Every three years, Smith participates in the International Society of Horticultural Science’s international fire blight workshop. Smith said this has helped him stay current and contribute to the understanding of the disease.

As well as testing controls for fire blight, he developed CougarBlight, a computer model that helps growers predict the best time to apply controls. The model is widely used in Washington and elsewhere.

Cherry fruit fly

Though Smith identifies himself as a pathologist, he’s also tackled insect pests, such as cherry fruit fly, which is a serious quarantine pest for cherries shipped to California. He began testing alternatives to the standard organophosphate insecticides and found several that would work, including spinosad.

He was one of the first to test the GF 120 bait (whose active ingredient is spinosad) against cherry fruit fly. Since there’s no tolerance for the pest in commercial orchards, there were no commercial populations to try it out on, so he and his technician Esteban Gutierrez tested it on the most heavily infested backyard trees they could find.

Unlike traditional pesticides, the bait is not sprayed on the whole tree. Smith and Gutierrez used a squirt bottle to apply it in their tests.

“It seemed so silly to put 12 to 15 squirts on a tree and expect that to control 6,000 flies on the tree,” Smith said. “But, lo and behold, there were no larvae in the fruit. The flies were dying before they laid eggs. Needless to say, that got our attention fast.”

Smith continued to get good results in tests and got the growers’ attention with talks and demonstrations. Soon, growers were cruising through their orchards on ATVs, squirting the bait and controlling the fly with a minimal amount of pesticide. It became the most-used material on cherries. Smith estimates that it saved cherry growers $10 million in spray costs over a five-year period. Then, a new pest showed up.

“Spotted wing drosophila put the skids on this real fast because it doesn’t work very well on that insect,” Smith said.


Smith has also been the go-to person on weed control. As the industry adopted microsprinklers in place of the old ­solid-set irrigation systems, weed control became important not just for reducing competition with the tree, but for making sure they didn’t interfere with irrigation.

When Smith began working in Extension, few herbicides were available. Roundup (glyphosate), which became available in the late 1970s, was revolutionary in controlling some difficult perennial weeds and grasses.

It has since been so widely used that plants are developing resistance to it, and the effort now is to encourage people to use other products and use glyphosate only once a year.
Smith is testing new combinations of herbicide and trying to come up with a range of effective programs so the new products don’t wear out. •

Smith honored for work

Tim Smith, Washington State University extension specialist, has received some of the Washington tree fruit industry’s greatest honors in recognition of his accomplishments.

At this year’s Okanogan Hort Day, the Okanogan Horticultural Association honored Smith for more than 30 years of service to the area’s growers by contributing $1,000 to the Washington Apple Education Foundation to establish a scholarship in his name.

“Anything you ask of him, he’s right there and available, and we very much appreciated all his knowledge,” said Dan McCarthy, association secretary. “He’s brought Extension to our county, and that’s been a great resource.”

Smith received the Washington State Horticultural Association’s Silver Pear Award in 2002 for exceptional services to the state’s pear industry. Presenting the award, grower and packer Barclay Crane said Smith had single-handedly saved the state’s Bartlett pear industry when he developed the CougarBlight model.

Four years ago, the university recognized Smith’s effort with the ­seldom-awarded Sahlin Faculty Excellence Award for Outreach and Engagement. Chelan County Extension Director Ray Faini declared that “with time, perseverance, and brilliant work,” Smith had changed the culture of an entire industry.

In 2010, when Smith was named Apple Citizen of the Year by the Washington State Apple Blossom ­Festival, Kirk Mayer, manager of the Washington Growers Clearing House Association, commented on his outstanding rapport with growers.

“I think there’d be a lot of growers in this area who would not be in business without his education, research, and outreach efforts,” Mayer said.

The impact of his work extends beyond Washington. In 2011, Smith was named the Northwest Cherry Institute’s Cherry King. He was crowned by the ­previous recipient John Carter of The Dalles, Oregon.

“Personally, on my farm, I’ve gained much from the work that Tim has done, including his groundbreaking research on how to control western cherry fruit fly,” Carter said.