Northwest wheat growers faced a "uniquely challenging" falling number season, and most of the problem came from a cause that may not hurt baking quality at all, according to Washington State University researcher Amber Hauvermale.

The falling number test measures starch damage by timing how long pins take to fall through a slurry of ground wheat and water; grain with a low number is sold at a discount. Low numbers have usually been blamed on late-maturity alpha amylase (LMA) or pre-harvest sprouting, both of which raise the starch-digesting enzyme.

This year the main driver was non-alpha amylase induced low falling number, or NAIL, which lowers the number without any alpha-amylase activity. Wheat Marketing Center testing found 118 low falling number samples out of 569, and 94 of them, about 80%, were presumed NAIL. Early results suggest NAIL does not affect cake quality, though some samples show lower protein. Its cause is unknown; one suspicion is cold early in grain development, after an unusually mild winter.

An enzyme activity test can tell NAIL from the other causes. "That combination of characteristics can help better assess whether that grain needs to be penalized, when there may not be a problem there at all," Hauvermale said. Some elevators discounted low falling number wheat and some did not, and the season has started a wider conversation, up to the Federal Grain Inspection Service, about whether the test is appropriate in a NAIL year.

Blending may also be easier: alpha-amylase damaged grain needs about ten parts of good grain to one, while NAIL grain may need closer to one to one, which the team is now testing. Storage, which helps with LMA, is not expected to change NAIL grain.

Hauvermale advised growers with low numbers to contact her or USDA researcher Alison Thompson, and to check WSU variety trials for performance against sprouting, LMA and NAIL. The report is by Matthew Weaver.

Photo: Robert Ashworth / Wikimedia Commons (CC BY 2.0)

Source: Capital Press