Wheat breeding aims to hit a moving target, as researchers aim to produce top yielders amid changing growing conditions. In Montana, plant breeders are working to meet what they see as a warming future.

Recently, Luther Talbert, a spring wheat breeder at Montana State University’s Department of Plant Sciences and Plant Pathology, shared research highlights in a lecture about the state’s cornerstone cereal crop. He discussed work to meet a variable and warming climate.

WHEAT LEADER: MSU professor Luther Talbert, shown in his Montana State University lab, has worked for Montana Agricultural Extension Service and at MSU’s College of Agriculture for 30 years as the university’s spring wheat breeder. (Photo by Kelly Gorham)

Talbert focused on traditional wheat breeding techniques that can help Montana growers remain profitable despite rising temperatures and the potential challenges of a longer growing season. The lecture was hosted by the Montana Institute on Ecosystems, a statewide institute housed at MSU.

In his remarks, Talbert noted that the goal of spring wheat breeding is to try to be steps ahead of what’s next. “There are always pests and diseases, but climate and temperature changes area variable and hard to forecast. What we know for sure is that we need to breed for climate variability tolerance,” he said.

This review of climate and variability started in 2009 when Talbert and Susan Lanning, a former MSU research associate, analyzed data from seven ag research centers in distinct locations across Montana. The research centers are part of the Montana Agricultural Experiment Station and located strategically across the state’s diverse climatological and ag environments.

The researchers had records dating back to 1950, with 58 years of detailed monthly weather from across the state. The centers are also authorized weather stations for the National Oceanic and Atmospheric Administration, and some have archived state data going back to the late 1800s.

Talbert examined those data and found that March temperatures in the state have risen 7 degrees F since 1950. He added that he wasn’t expecting that much of a change over the years. “Most farmers know, at least informally, [that] seasonal temperatures have changed over time, but here we had this verified climate data set for Montana — and it was showing a consistent uptick in March temperatures each year.”

A warmer March means earlier planting dates for wheat farmers because the ground thaws sooner; this results in a longer growing season. However, Talbert and Lanning also found that temperatures in July were rising over the years, though not as much as the March temperatures.

The next step was to match weather data with wheat yield. The researchers tracked yield for a spring wheat variety called Thatcher, which research centers had grown since the 1950s. Talbert said that Thatcher data were a common factor they could look at to determine weather variation on a specific variety over the years.

Tracking Thatcher’s yield over time, they found that the warmer March was a positive element, but a hotter July was not. “A longer growing season is good news for farmers, but it gets risky when the temperatures also get hotter in July,” Talbert said. The result is that farmers can plant earlier, but wheat suffers in July if temperatures rise too much.

Heat and drought
July and August is when spring wheat goes through grain fill, a four-week process that essentially determines yield and quality for the crop, which is used in baking and milling. If temperatures are too hot during the process, the plant is too stressed to adequately complete grain fill and reach its full potential.

Talbert noted that if it gets too hot, leaves brown, photosynthesis stops and the wheat kernel essentially stalls, cutting yields. And there’s another issue: “Unfortunately, hotter temperatures during grain fill often go hand in hand with drought conditions.”

Summer 2017 brought Montana growers one of the worst droughts in recent history, which produced a 40% reduction in grain yield, according to USDA. Wheat yields count for a lot, given that Montana is the nation’s second-highest producer of spring wheat, exporting 75% of its wheat to Asian markets.

“Montana’s calling card in many ways is hard wheat, with high protein and strong baking and milling qualities, which global markets want,” Talbert said. “So, essentially, warmer temperatures have the ability to cause an economic impact that will be felt at the farm level first.”

Talbert’s work is moving the needle. He has worked in the Montana Agricultural Extension Service and MSU’s College of Agriculture for 30 years, and with funding from farmer checkoff funds from the Montana Wheat and Barley Committee, his spring wheat breeding program has seen success. Talbert and his program have developed some of Montana’s top-planted wheat varieties, bred specifically for high yield in dry conditions.

An important genetic advancement has been incorporation of genes to help the plant stay green longer during grain fill. The stay-green traits help the wheat plant tolerate the higher July heat by continuing to fill, according to Talbert.

A popular variety is Vida, which has genes that create a semisolid stem, incorporated from an earlier variety named Scholar. The semisolid stem gives the plant some resistance to the wheat stem sawfly, a costly Montana pest.

Talbert says breeding for drought tolerance and hotter temperatures will continue to be a priority, as the program strives to ensure continued profitability of spring wheat production in Montana.

“Spring wheat just doesn’t do well in hot climates,” he said. “We certainly can’t predict what the future holds for Montana, but we can be sure that we need to keep improving our varieties to remain sustainable in a warmer environment.”

Source: Montana State University