New seed certification program tackles weedy rice

Luis Espino, a University of California Cooperative Extension rice farm adviser based in Williams, Calif.

WILLIAMS, Calif. — A new program helps protect California’s specialty rice fields from an undesirable strain known as weedy rice.

A University of California-affiliated nonprofit organization’s new Rice Seed Quality Assurance Program launched last year to examine and judge specialty varieties that couldn’t be certified under the Association of Official Seed Certifying Agencies’ existing program.

For example, California has thousands of acres of Koshihikari, a specialty Japanese sushi variety that’s sold at a premium back to Japanese markets. Because it’s a specialty variety brought to California, it was never in the domestic seed certification program, said Timothy Blank, who handles field inspections for the UC-Davis-based California Crop Improvement Association.

The new quality program verifies producers of rice seed and seeks to assure buyers that a product has met purity standards. The program has buy-in from many of the state’s seed producers, Blank said.

“So far I’ve been really surprised with the support we’ve gotten from all the people who should be in the program,” he said. “Everyone’s been cooperative. ... I think they are because they understand that this has the potential of solving the weedy rice issue.”

Weedy rice, also known as red rice, belongs in the same genus and species as cultivated rice but is one of the most damaging weeds of rice worldwide. The plant shatters prior to harvest, spreading hundreds of thousands of seeds on the ground, Blank said.

Reports from the southern U.S. have shown that a presence of weedy rice in fields reduced yields by up to 60 percent, the UC Cooperative Extension notes. And because it is a very close relative of cultivated rice, the herbicides used in rice don’t kill it, the UCCE explains.

California was practically free of weedy rice for the past 50 years, but it has recently resurfaced and was confirmed in more than 10,000 acres as of the end of 2016, according to the university.

“Weedy rice is becoming more common,” said Luis Espino, a UCCE rice farm adviser in Williams. “We’re starting to find it in different places. The suspicion was that it’s been moved around in seed that’s not been certified.”

It’s relatively easy to obtain rice seed, Blank said. One of the ways that companies bring in new varieties is by requesting seed through the USDA’s germplasm seed bank — which anyone can do — and experimenting with different lines, he said.

“They’re not doing any breeding,” he said. “They’re just taking something that somebody else had gifted to the seed bank.”

However, little is sometimes known about the seed that was donated to the bank.

Established in 1919 as the International Crop Improvement Association, the Association of Official Seed Certifying Agencies includes officials from the U.S. and seven other countries. It began certifying crop seeds in the 1920s, and the first rice seeds were certified in the 1930s, Blank said.

“It’s basically a pedigree program,” tracking rice seed from the time it leaves breeders’ hands to the time it gets to conventional growers, Blank said.

For specialty seeds that can’t be verified under the existing program, California’s Rice Seed Quality Assurance Program was formed for producers who agree to abide by nearly a dozen growing guidelines, including assuring that planting equipment be thoroughly cleaned and inspected before use.

When a seed grower changes varieties, the field must be inspected before planting to make it eligible for the following year. Inspections verify a field’s freedom from weedy rice.

Weedy rice can take years to remove from a field, he said.

Though it will likely take time, Blank believes the effort will eventually resolve California’s weedy rice problem.

“There’s some that believe it can’t be done, but it has been done before so I’m optimistic,” he said. “We had a bad weedy rice problem back in the 1920s and ’30s, and it was for all intents and purposes eradicated for decades. I believe it can be eradicated again through a good seed program and persistence.”

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