SPOKANE — Researchers are advancing on several fronts in their efforts to manage starch damage in wheat.

“We’re close,” said Camille Steber, USDA research plant molecular geneticist.

“We’re within a season of having a new rapid test for grain receival that will hopefully help improve post-harvest management, and hopefully allow us to better segregate good from bad grain as it goes through the grain chain,” said Amber Hauvermale, Washington State University assistant professor.

Wheat with a low falling number has starch damage and must be 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 starch damage that year cost farmers more than $30 million in lower wheat prices, according to estimates.

Causes are pre-harvest sprouting when cool, rainy weather occurs before harvest, or late maturity alpha amylase (LMA), which occurs because of cold weather during grain filling.

Steber and Hauvermale provided an update on their work during the Spokane Ag Show.

Rapid testsBeta testing of the new rapid tests are likely to begin in March with stored samples from 2023, and then with key collaborators this summer.

The rapid test is intended for grain elevators at first.

“(They) said, ‘We really need a red light, yellow light, green light test,’” Hauvermale said.

While the falling number test is expensive, slow and can’t be run in the field, the new immunoassay tests are rapid, specific, quantitative and customized for enhanced sensitivity.

The new test takes 5 to 15 minutes, Steber said.

The rapid tests could also serve breeders earlier in the development stage, Hauvermale said.

“They need something that allows them to screen a whole bunch of things really quickly,” she said.

Wheat breedingBreeding programs are aiming for wheat varieties with higher falling numbers.

Breeders have found eight potentially “perfect” genetic markers for Pacific Northwest wheat, Steber said.

An overlap between LMA tolerance and pre-harvest sprouting tolerance suggests that researchers should be able to develop markers to enhance both traits in early-generation breeding lines.

There are also examples of lines that are LMA susceptible but pre-harvest sprouting resistant, or vice versa. It’s important to confirm both traits in advanced lines, Steber said.

Grower perspectiveThe researchers want to talk to farmers about how low falling numbers has impacted them, Hauvermale said.

Farmers can also identify and provide samples of wheat with low falling numbers for further testing.

The researchers want to know if the rapid tests could eventually be useful for farmers in the field.

Such information may help avoid mixing wheat with low falling numbers with higher falling numbers at the farm level, Steber said.

“You might come to know that some part of your farm lies a bit lower and tends to have a lower falling number,” she said. “Maybe it’s wise to keep that truckload separate from everything else.”

“It’s complex, and there are a lot of logistical challenges, but I think we can rise to the challenge,” Hauvermale said.

Contact the researchers

Amber Hauvermale: ahauvermale@wsu.edu

Camille Steber: camille.steber@usda.gov

Alison Thompson, USDA research geneticist: alison.thompson@usda.gov