Researchers aim to breed heat- and drought-resilient hops

October 1, 2021
Researchers aim to breed heat- and drought-resilient hops

After this summer's heat waves scorched Northwest hop yards, reducing yields, many growers are asking for more heat- and drought-resilient hop varieties — and researchers, relying on new funding, are answering the call.

"I'm sure growers at the January (American Hop Convention in Florida) will demand more hops that can stand up better against wildfire smoke, heat and drought," said Peter Weathers, a grower in Salem, Ore., whose hop fields this year saw heat losses.

On the private industry side, growers are pushing breeders of proprietary hop varieties to develop more climate-resilient hop plants.

On the public side, USDA and university researchers are using new federal and private funds to improve public hop varieties and develop new ones.

John Henning, a hop geneticist at USDA who has an appointment at Oregon State University, is one of the nation's lead researchers in this area.

Henning's hop breeding program, spanning Washington, Oregon and Idaho, involves about 100 different plant family lines.

The summer's heat, Henning said, helped reveal which varieties and genetic lines are strongest.

"This was a good year to find out which (hops) are most susceptible to heat and which ones are not," said Henning.

Through his initial research, Henning noticed three major trends.

First, Henning found that triploid hop cultivars — hops with three rather than two sets of chromosomes — tend to be more drought-resistant.

Second, he found that later-establishing varieties performed worse because the young hops didn't make it far up the trellis before the heat hit.

Finally, he said hop plants with longer or more fibrous root systems seemed to fare better.

Although Henning didn't specify which varieties are most and least resilient by name — he's not permitted to do so as a USDA researcher — others in the industry have been more candid.

Several growers, along with Michelle Palacios, administrator of the Oregon Hop Commission, told the Capital Press that Citra and Centennial were among the varieties most impacted by the heat, especially Citra because the plants were young when the heat hit.

Citra is highly sought-after by brewers for its citrusy flavor and aroma.

Weathers, the Salem farmer, said growers walk a fine line between growing what holds up well under heat while producing what brewers want.

Palacios of the commission agreed.

"You can breed the perfect hop — it's got disease resistance, can handle water stress and heat — but if people don't want to buy it, what's the point?" she said.

Another grower, who spoke on condition of anonymity, said many popular hop varieties are not the most sustainable.

"Some of the popular varieties like Citra and Simco require more spraying or more water," the grower said. "The brewers and end-consumers are not always sophisticated enough to know that the hops they like best might have a bigger carbon footprint."

Henning of USDA said researchers will work to improve popular varieties through breeding and management strategies, while also developing new varieties.

2021 is an exciting time for hop research, Henning said, because new money from Congress, research at state universities and new USDA hop research positions are making progress possible at a rate he's never seen before.

"It's an exciting time, to be honest," he said.

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