Published 7:00 am Thursday, January 25, 2024
PULLMAN, Wash. — Northwest wheat farmers will soon have faster and better tests for starch damage in their wheat crops, a Washington State University researcher says.
“With fluctuations in weather patterns, unpredictable rain and unpredictable cold snaps, it’s quite possible to have events like what happened in 2016,” said Amber Hauvermale, a research assistant professor.
The commonly used falling number test measures starch damage in wheat. Technicians determine how long it takes two pins to fall through a ground wheat-water slurry, measuring its viscosity. Wheat with a low falling number has starch damage and is sold at a discount because it reduces the quality of baked goods and noodles.
Farmers were caught off guard in 2016 when 44% of soft white wheat samples and 42% of club wheat samples tested below 300, the industry standard. The industry estimated the damage that year cost farmers more than $30 million in lower wheat prices.
During this year’s Spokane Ag Show, Hauvermale will provide an update on industry efforts to quickly detect and address low falling numbers.
“The intention is to develop diagnostic tools that can be run faster than a falling number test … at the elevators or in the field,” Hauvermale said. A new rapid test is “on the near horizon,” she said.
Growers are most at risk in two instances:
• When the crop is in soft dough stage, about 25 to 28 days after the wheat flowers. At that time, if growers were to pull off a kernel, it would be green and squishy.
“If you get a cold snap or an extreme temperature drop when the grain is in that state, depending on how susceptible it is, there may be a problem there,” Hauvermale said. That’s late-maturity alpha amylase (LMA), the enzyme that occurs as a result of large temperature fluctuations during late grain filling.
• After the grain is completely mature and ready to harvest, rain could be an issue, depending on how susceptible the wheat variety is to pre-harvest sprouting (PHS).
“Eventually we’ll be able to distinguish between whether you have sound grain or whether you have LMA or PHS,” Hauvermale said.
Wheat breeders hope to eventually be able to identify and remove susceptibility in a variety.
“Our wheat breeders here and around the globe are making monumental strides to breed the problem away, but we’re not there yet,” she said.
One of the most difficult things about the falling number problem is that there’s virtually no way to distinguish between late-maturity alpha amylase or pre-harvest sprouting.
There’s no visible signs of the enzyme in the grain. It’s evident in severe sprouting, but “at that stage, you have a massive problem,” Hauvermale said.
“Running a falling numbers test will tell you something has happened,” but won’t identify the cause, Hauvermale said.
Hauvermale estimated that researchers ran more than 300 samples to calibrate the new rapid test.
The researchers wanted to identify a range of samples specifically from the field, with falling numbers between 200 and 300, to test the correlation between the rapid test and the falling number test, to ensure the two tests deliver the same number. The focus is on soft white wheat and soft red wheat classes, Hauvermale said.
“It took a lot of searching this year for the perfect samples,” Hauvermale said.
The falling number test is the global standard for measuring soundness of the wheat, she said.
“All of the growers understand falling number, the elevators are working with falling number, the bakers and millers often are working with falling number,” she said. “That’s what the industry uses, so we wanted to make sure we were incorporating that into the output of the test.”
Overall, in Washington, farmers experienced “pockets” of low falling numbers. Hauvermale credits the “weird” planting season, as farmers had delays in winter and spring, which also delayed harvest.
Researchers are also working to predict if weather in a given year is likely to elevate the risk of low falling number. Hauvermale calls it an “early warning detection system.”
“The hope is that if people in a general area know, the elevators can be on alert and have a better way to manage as the grain is coming in, or ramp up testing,” she said.
