MOUNT VERNON, Wash.—A Washington State University research scientist has identified worn-out soil as the main culprit for declining beet seed yields in the Skagit Valley.
Reviving the ground will take well-timed irrigation, careful fertilizing and winter cover crops, plant pathologist Lindsey du Toit said.
“It’s a complicated story. It’s not a simple solution,” said du Toit, stationed at WSU’s center in Mount Vernon.
Northwest Washington, particularly Skagit County, is reputed to be one of the world’s top producers of spinach, cabbage and table beet seeds.
Beet seed producers do not disclose yields, but WSU Skagit County Extension Educator Don McMoran estimated yields declined by one-third between 2010 and 2013.
Beet seeds in Skagit County were a $2 million crop in 2011, $1.9 million in 2012 and $1.5 million in 2013, according to McMoran’s estimates.
In the 1940s, beet seed farmers were plagued by a virus spread by aphids. Because beet seeds need two growing seasons, the aphids were able to perpetuate the virus while the current year’s crop overlapped with the next year’s crop.
The solution was for plants to winter on Whidbey Island, away from the aphids but close enough to truck the roots for spring planting in the Skagit Valley.
The solution still works. Du Toit concluded that neither pests nor disease was causing the decline in yields.
“It would have been a little easier for me as a pathologist if it was a disease,” she said.
Several WSU researchers worked on the problem. Weed scientist Tim Miller conducted on-farm trials with herbicides, and entomologists Lynell Tanigoshi and Bev Gerdeman scrutinized crops for pests.
A breakthrough came last winter when du Toit tested beet leaves and found plants were suffering from a calcium deficiency after a winter on Whidbey Island.
The soil wasn’t holding enough water to dissolve nutrients for plants to absorb. The plants were being transported in a weakened state and transplanted in soil that also was broken down by years of growing the same crop.
The plants were vulnerable to being stressed by a lack of moisture. The county’s vegetable seed farmers, who number about two dozen, have not traditionally irrigated. But last summer, more did.
Farmers shared water resources, said Jack Hulbert, the co-owner of Hulbert Farms and Skagit Seed Services.
“This year the yield was average, which we haven’t seen since 2009,” he said.
Foliar feeding also can give plants a jolt of nutrients. But du Toit said fertilizer won’t cure what ails the ground.
Also, fertilizer, Hulbert said, can have the unwanted effect of delaying plants going to seed. “Pouring more on isn’t going to be a good thing,” he said.
WSU Whatcom County Extension agriculture agent Chris Benedict recently began meeting with farmers to discuss cover crops to restore soil nutrition and structure.
Hulbert said that after the harvest he planted cover crops, a practice discontinued 15 years ago to cut costs.
He said the outlook for beet seeds in the valley is good. “It’s just a matter of getting our soil back.”
Last growing season, McMoran regularly updated farmers on soil moisture to help them irrigate before the plants were stressed.
It’s too early to declare beet seed yields will bounce back, but the harvest was reason to be optimistic, he said.
“When you have had really crummy crops and you have an average one, it’s exciting,” McMoran said.
He said he has not received any reports suggesting cabbage and spinach seed yields have suffered a decline.
Du Toit said beet seeds may be the “canary in the coal mine,” alerting valley farmers to soil damage.
“All the crops are impacted by the quality of the soil,” she said.
Source: www.capitalpress.com