Onion World: The Voice of the Onion Industry

Dr. Bill Dean

Bringing Classroom Science to Walla Walla River Farms

Onion World
May/June 2005

Can educator bring classroom science to the art of growing Walla Walla Sweet onions?

Dr. Bill Dean, hired as general manager of Walla Walla River Farms in 2003, came highly recommended from area growers familiar with his ability to bridge the gap between theory and practicality. With a Ph.D. from Washington State University and teaching experience at both Michigan State University and WSU, Dean also has worked in private industry. He served five years at AgriNorthwest as director of agronomy and three years at Judell Farms growing various vegetable crops. Both are located in Washington state.

After completing his Ph.D. in 1976, Dean briefly taught and did research on various vegetable crops at MSU before being lured back to WSU to fill a position vacated by Dr. Bob Kunkel, a professor and well-known expert in potato production. Dean continued with WSU for about three years, left for five years to serve at AgriNorthwest, came back to the university as part of its International Marketing Program for 14 years and then returned to private industry.

Asked recently if he would like to share any of his trade secrets for growing Walla Walla Sweet Onions, Dean reminisced of an experience he had had years before while working for the late Martin Wistinsen, then CEO of AgriNorthwest.

“I had helped develop a formula of sorts for growing potatoes that I later shared with students at the university,” Dean recalls. “I actually wrote a book. One day, Martin approached me and asked point blank: ‘Bill, you’ve got these procedures. You’ve written them down, but give them to 16 different men and none seem to be able to achieve the same results. Why not?’

“My answer to that has always been, take the same recipes and go to the field, but if you apply them at the wrong time, you’ll do poorly,” Dean says. “I’ve always warned my students, ‘Pay attention to the details. Timing is as important as the particular task you are doing.”

250 Acres of Walla Walla Sweets
Two hundred fifty acres of Walla Walla Sweets are being grown at Walla Walla River Farms this season. All fields are between the towns of Lowden and Touchet in the Walla Walla Valley, 10 to 15 miles from downtown Walla Walla.

Walla Walla River Farms is owned by Keystone Fruit Marketing, headquartered in Green Castle, Pa., and a group of local investors, most of whom have lived in the area for years. Keystone owns 50 percent of the farm and handles all of the onion marketing. The company also markets Walla Walla Sweets grown by other partners involved in the curing and storage side of the business. Sweet onions also are brought in from Georgia and Peru.

All of the onions grown at Walla Walla River Farms this year are transplants, planted to mature in time for the late-season niche (mid-July to the Labor Day weekend).
This past year has not been a profitable year for most storage onion growers across the country, but Dean is optimistic about 2005 Walla Walla Sweet crop.

“I’d like to say that prices are going to be great for growers this year, but the reality is much will depend on what’s happening in Georgia,” Dean admits. “If the quality there is good and acreage is down—and it appears it may be—look for better prices. Generally speaking, what happens in Georgia has a major impact here. The Texas crop also influences our market, and raining weather there may have shortened this year’s crop.

“We’ve had an ideal season so far. The plants have gone in nicely, and, as the season progresses, I expect to see a very, very good crop,” Dean predicts.

Onions produced at Walla Walla River Farms are certified sweet via pungency testing. “That’s something we are seeing more of nationally,” Dean points out. “People are asking for testing to verify pungency. They want to know that their onions, indeed, are sweet. There is considerable debate over what is, and what is not, the right way to test onions, but we like the procedure we’re using.”

The farm uses the Schwimmer and Weston method, modified in the 1990s by Dr. Bill Randall of the University of Georgia to handle larger samples. The methodology was developed on the East Coast in the 1960s.

Walla Walla River Farms’ onions average 3.5 on the pungency scale.

“We have onions in the 2.0 range and others up to 4.5. Our limit is 5.2,” Dean explains, adding that, in his personal opinion, the “perfect” onion, the one with that “truly nice taste,” falls within the 3.5 to 4.0 range. Walla Walla Sweets are an intermediate-day onion in terms of type and have a loyal following of consumers who look for them each summer..

Drip Irrigated
Onions on the farm are all drip irrigated to help reduce disease, Dean says. Walla Walla Sweet Onion varieties do not have the disease resistance that some hybrid onions do, so growers have to closely watch for any sign of disease. Among the more common diseases are mildew, black mold and botrytis. Since the onions are all cured after harvest, botrytis has not been a major issue.

Dean likes to keep his soil moisture content at approximately 85 percent. He uses the kind of moisture probes that can be permanently installed throughout the season. One probe is placed at shallow depth and a second at the one foot level at each site. His goal is to monitor moisture movement out of the drip system down into the soil profile. Typically, Walla Walla Sweet roots are at the 12- to 18-inch depth.

While white rot remains a challenge for growers farming in the older areas of the valley and requires fumigation to control, Dean has yet to see any signs of the disease on his farm. Most of his tracts of land have never had onions on them before, and, those that have, he is well acquainted with their history.

Labor availability has not been an issue this year, the general manager says, but the long-term outlook is anything but certain. Due to the rapid decline of asparagus production in Washington state in recent years, jobs attracting field workers are drying up. Hand labor is critical to the Walla Walla Sweet industry. Both planting and harvesting require an extensive labor pool.

“A good worker typically plants two to three crates of transplants per day,” Dean points out. “There are 5,000 onions in a crate. We plant just shy of 140,000 plants per acre, so it takes about 27 crates per acre. When you do the math, the number of workers required adds up fast, depending upon how many acres you need to plant per day.”

Mechanical Harvesting Ahead?
Dean continues to monitor what’s happening on the mechanical harvesting scene, but feels the technology is not yet perfected enough to make the investment.

“It’s getting close, but if you make a $300,000 investment in a harvester and the concept doesn’t work, it’s difficult to sell the machine to somebody else,” he frowns. “Taking both the tops and roots off of a soft onion is asking a lot from a piece of equipment. Some harvesters do a great job with the tops but have a more difficult time with the roots. Walla Walla Sweets, in particular, have very large, long roots that must come off. You don’t want them in your finished pack.”

Dean says he wants to watch closely what’s happening with the Top Air, Shuknecht & Sons and Nickolson (from Great Britain) harvesters undergoing testing in Georgia and other areas of the country where sweet onions are grown.

“Somebody is going to come up with the right combination, and growers will quickly begin using these machines when they do,” he opines. “While the jury is still out, we’ll be watching and will make the move when it’s cost-effective to do so.”

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