Using timing of risks and benefits to breed barley for future climates

Printed with permission from Sonia A. Hall, Center for Sustaining Agriculture and Natural Resources, Washington State University. Originally published on AgClimate.net.

This article is part of a series where Hall shares insights from conversations they had with public plant breeders across the Pacific Northwest about their breeding programs and how climate change considerations intersect with their work. Through these conversations, Hall wanted to better understand the complexities of the plant breeders’ world, where there are elements that already provide useful information about adapting to future climates, and where there are questions—about the climate in the future, or the plants’ responses, or production, market, or other factors affecting a particular crops’ future—that intersect or even overshadow questions about how to prepare for future climates.

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Barley, like wheat, can be sown in the fall, overwinter, and grow and mature the next season, or can be planted in the early spring, and have a shorter, quicker growing season. For a variety of reasons, however, spring barley is considered “the good one” for malting and producing beer. Yet as Dr. Patrick Hayes, Oregon State University’s malting barley breeder, works to develop barley varieties that will be grown under future climates, fall barley is key. The timing of growth and the resources it taps can help avoid a variety of issues that will otherwise impact barley yields and quality (whose main indicator is the percent protein in the grain). Read on for Dr. Hayes’s explanation of why fall barley is becoming increasingly attractive.

SAH: Please describe the focus of your breeding program.

PH: Our breeding program is focused on barley varieties for malting, food, and animal feed. We primarily target growers in the Pacific Northwest, though varieties released here are also adapted to, and used across, a broader geography. The malting and beer brewing industry is why barley exists. Its use for food is a niche market at this time. And animal feed is a default (alas, usually a money-loser) for barley that does not make malt grade.

SAH: Do you currently integrate climate change considerations into your breeding program? How? Are there conditions that make it hard, or unnecessary, to integrate climate change considerations into breeding?

PH: Yes. High temperatures and limited moisture can lead to high protein content in barley, impacting its quality for brewing. The genetics of drought tolerance are super complex, so breeding drought tolerant varieties, particularly with malting quality, is a challenge. We therefore breed for fall-planted barley that can make best use of the available winter moisture and, in irrigated fields, reduce the need for irrigation. This will be beneficial under future conditions with more frequent, and less late-season irrigation water available as snowpacks get smaller and melt earlier. The added advantage of fall barley is that it matures a little earlier, so has a better chance of avoiding heat extremes in the summer. One of our local brewers described the impact of the 2021 heat wave in optimum dryland barley growing areas as a “bloodbath.”

SAH: What traits or characteristics do you focus on in your current breeding program? Do those traits or characteristics confer the ability to adapt to future climates, that could be warmer in all seasons, with increasing variability and extremes? Or could they be affected by changing climates?

PH: Even though the net trajectory as the climate changes is for warming, extremes, including late frosts, are becoming more volatile. Dealing with volatility is a challenge. This explains why, though it’s somewhat counterintuitive, we breed for low temperature tolerance even as the net trajectory is warming. Fall-planted barley requires a tolerance to low temperatures. This a complex trait that we are slowly unraveling. Low temperature tolerance is coupled with flowering time. Some varieties need certain cold periods before they are able to grow and become reproductive. Others simply respond to the length of the day, which becomes their cue for switching to reproductive growth. This is what we are unraveling, but we see options that we can use in breeding. And of course you need all the other positive traits required of a barley variety in terms of resistances, quality, etc.

SAH: What trade-offs do you consider, or would you need to consider, in breeding for warmer conditions, longer frost-free periods, and likely wetter springs and winters, drier summers, and a shift in the availability of irrigation water to earlier in the year (as expected in much of the Pacific Northwest?

PH: Breeding for drought tolerance per se is a huge challenge. We are leaving that to others. Our strategy is avoidance via fall planting. Fall planted crops also mature earlier than spring planted crops, allowing them to escape the hottest days of summer.

SAH: Are there resources – online tools, Extension or other publications, events, etc. – that you know of that can help agricultural professionals integrate climate change into their work assisting producers with variety choice? Or any resources you wish existed?

PH: Certainly necessary and something I intend to get involved with once the decks clear a bit.

This conversation glosses over a whole range of factors that barley growers need to consider, including how barley fits into their rotation, and whether they have the storage capacity and infrastructure to handle malting barley, if they have access to contracts for malting barley to even plant it in the first place, to say nothing of all the management practices that can affect yields and grain quality. Yet breeding for cold tolerance to have productive fall barley varieties that can avoid the worst of what climate change might have in store for our region is an interesting twist on other approaches we are hearing from plant breeders. This twist may also be of interest to other crops that could be planted in the fall. And I can’t help but be personally intrigued by the irony of breeding for cold tolerance in a warming world.