In the state’s dry, nutrient-deficient soil, CU Boulder researchers and others aim to learn if the crop can survive and even thrive in a hotter, drier future

Venture through Colorado’s Front Range during the summer months and you’ll likely spot vibrant yellow sunflowers growing wherever they can, like a thin crack in the sidewalk or along the edge of a bustling highway. Head east toward Denver International Airport and you’ll find entire fields of them.

Soon, you may be seeing even more of these cheery blooms throughout the Centennial State.

As the planet gets hotter and drier, farmers in Colorado may lean more heavily on commercial sunflowers to help hedge against the effects of human-caused climate change. These hardy plants don’t need as much water as other crops, nor as many inputs like fertilizer. 

They’re tough enough to withstand hot and cold temperatures and, on top of all that, they can be transformed into an array of valuable products ranging from cooking oil to edible protein, birdseed and more.

With a new $1.2 million grant from the National Science Foundation, a team led by scientists at the University of Colorado Boulder will begin unraveling some of the sunflower’s genetic mysteries in hopes of making the crop even more resilient and productive in the future. 

“It’s never going to compete with corn or wheat in some of the breadbasket states, but where it really shines is in the kinds of habitats like we have here in Colorado—where we have less water and fewer nutrients,” says Nolan Kane, a CU Boulder associate professor of ecology and evolutionary biology and the principal investigator for the project. 

“It’s proved to be an environmentally sustainable and economically sustainable crop.”

Breeding roadmap

With the three-year federal award, researchers will analyze more than 50 years of measurements taken from various commercial sunflower varieties grown in dozens of locations and climates across the country. 

Then, they’ll pinpoint the genetic underpinnings of the plants’ adaptations to their environments. In particular, the researchers are curious to know how the sunflower’s timing, or phenology, has changed over time—such as when the seeds germinate or when the plant flowers—and whether those shifts have helped or hurt the plants.

That knowledge, coupled with future climate modeling predictions, could serve as a roadmap for sunflower breeders like Brent Hulke, a research geneticist with the U.S. Department of Agriculture (USDA) and a CU Boulder associate adjunct professor of ecology and evolutionary biology. 

“We expect to have a better appreciation for how climate is affecting this important crop in the Great Plains, and tie it back to the plant’s genetics, which will help us adapt breeding strategies to enhance stress tolerance, as well as enhance recommendations for farmers in terms of variety choices in the future,” says Hulke, who is also a co-principal investigator on the NSF grant. 

Sunflowers’ long roots

Sunflowers are native to North America. Indigenous peoples saw the value in this annual plant and began cultivating it thousands of years ago. They cracked open the hulls and ate the tender seeds as snacks or ground them into flour or meal to bake into bread or incorporate into other foods. Beyond the edible applications, they also used sunflowers for ceremonial and medicinal purposes, as well as for decorations, body paints and dyes.

But despite this long, fruitful history on the continent, sunflowers didn’t catch on as a modern agricultural crop until the 1960s. Since then, the plants have thrived in the more arid regions of the western Great Plains—chiefly, North Dakota and South Dakota. Worldwide, sunflowers have also become an important crop in Ukraine (as well as the country’s beloved national flower), Russia, Argentina, Turkey and parts of the European Union.

Optimizing crops for the future

In Colorado, farmers are increasingly planting sunflowers to help diversify their crops and make use of less-than-ideal farmland, even though plant breeders haven’t developed varieties suited to the Centennial State’s climate. 

As such, one aim of the project is to help breeders develop sunflower varieties specifically for Colorado. Another is to help improve sunflower breeding more broadly in the face of harsher future climates. 

“I don’t think any one species is going to be the right answer (to adapting to climate change)—it’s important to have a range of species, and I worry that our current agriculture is too dominated by too few species,” says Kane. 

“By improving our ability to use such a sustainable crop, our goal is not to replace all corn and soybeans and other crops with sunflowers. It’s to provide an additional crop.”

One big challenge all plant breeders face now is how quickly the climate is changing, which can make it tricky to develop plants for an unknown future. But Kane says that’s all the more reason to dig into the historical data and glean every bit of information possible to make smart breeding decisions.

“Right now, we’re not keeping up, we’re not optimizing our crops,” he says. “Our job is not to predict the future climate, but if we do assume that some of these climate predictions come true in a particular environment, what should we breed for in the future? Sunflower is not a huge crop in the U.S., and yet we can help to make it a better, more efficient, sustainable crop in the future, just by taking advantage of the information we already have.”

Other co-principal investigators on the project are Sarah Elmendorf, a research scientist at the CU Boulder Institute of Arctic and Alpine Research; and Colin Khoury, senior director of science and conservation at the San Diego Botanic Garden.