Keeping Up With Alfalfa Advances
Whether it’s new conventional varieties with better winter hardiness and disease resistance, or a new GE product with herbicide resistance and improved digestibility, there’s a lot happening in the alfalfa seed market. Here’s a snapshot of the latest advances and what’s coming down the pipe.
In the world of forage seed, alfalfa gets a lot of press, due in part to a genetically engineered variety that has renewed interest in alfalfa seed.
Even before Forage Genetics International (FGI) began selling its HarvXtra alfalfa seed with Roundup Ready technology to farmers in Eastern Canada in 2016, the alfalfa industry was split on whether it was a good idea. On one side, alfalfa seed producers in the West feared contamination risk, endangering alfalfa seed exports. In the East, growers wanted the ability to grow herbicide tolerant alfalfa for livestock feed.
In the end, FGI decided to launch the product in the East for hay production only, and it’s not sold in Western Canada. It was also available to U.S. growers for planting Jan. 1 of this year. Despite the controversy, the issue put alfalfa back in the spotlight.
“It’s what often gets lost when people talk about alfalfa — the conventional side and some of the strides being made,” says Erick Lutterotti, general manager of Gold Medal Seeds, a subsidiary of FGI, and vice chair of the Canadian Seed Trade Association’s Forage and Turf Committee.
Especially exciting for Lutterotti are new varieties of multifoliate alfalfa that have been bred to be winter hardy.
“That’s the big thing in conventional alfalfa,” he says, noting that winter hardiness ratings indicate the potential longevity of the alfalfa stand.
Lutterotti says that although fall dormancy is related to winter hardiness, the latter is separate from fall dormancy. In recent years, breeders have separated winter hardiness from fall dormancy.
“In the past, multifoliate alfalfas came with a 4 or 5 fall dormancy rating, meaning it wakes up early and goes to bed late,” Lutterotti says. “Inherently, creeping-rooted alfalfa was the most winter hardy, but those varieties were best suited for lower-yielding two-cut systems.
“Now we have a very high-quality alfalfa — dairy quality — that’s still at that 4 fall dormancy rating, but you have a winter hardiness below 2. This gives you lots of options as to your farming system.”
Regional differences are the key to knowing what alfalfa variety is best, Lutterotti adds. If the crop is meant for short-term growth, moderate winter hardiness is usually adequate. For long-term stands, a lower winter hardiness rating is often a good idea, but it can depend on a couple factors, he says.
“In regions with more snow, a lower winter hardiness rating may not provide much additional protection, but you never know. You don’t want the grower to just assume that they’re going to get a lot of snow cover next winter. You might not get as much snow in a given year, so it might be a good idea to go with an alfalfa that can withstand exposure to the cold better.”
He recommends retailers work with their customers to determine the variety that is the best fit for their specific situation.
Improving Yield, Persistence, Quality
The advances in alfalfa products, such as high-quality winter hardy varieties, are due in part to the work of people such as Annie Claessens, Agriculture and Agri-Food Canada’s Quebec Research and Development Centre forage breeder. Claessens is part of a multidisciplinary team of researchers working to improve the forage crop.
Like most breeders, alfalfa breeders strive to boost yields. The key is lowering the dormancy, but doing so can have unwanted effects on alfalfa persistence. It’s an interesting conundrum that Claessens and her team are challenged with.
“We’re trying to help growers extend the alfalfa growing season from late summer through to early winter, so we want less dormant cultivars. However, when they’re less dormant, they generally have lower winter survival.”
Some significant gains have been made in recent years, like the kind Lutterotti refers to, where winter hardiness has been improved while keeping fall dormancy the same. But there’s a ways to go, Claessens notes.
“Those two traits can be improved simultaneously. We’ve developed an indoor selection method to decrease dormancy but increase freezing tolerance, which is one of the most important factors in lowering winter survival under our climatic conditions.”
Breeding for better freeze tolerance involves creating plants with perennial organs (crown and roots) that can withstand freezing temperatures. Her team has been able to increase the freezing tolerance of alfalfa by 5 degrees Celsius.
Claessens and her colleagues are also working on disease resistance, which is the second most important factor for lowering winter survival. Breeding efforts focus on Phytophthora root rot and Aphanomyces root rot to reduce the effects of cold and wet soil conditions.
Phytophthora root rot can survive for many years in the soil, and may attack alfalfa even after long rotations to other crops. Aphanomyces root rot, caused by a pathogen very similar to Phytophthora, attacks both seedlings and adult alfalfa plants and can dramatically reduce yield.
“We’ve developed an indoor selection method to identify which plants are highly and moderately resistant to those diseases,” Claessens says. “We can select plants with greater resistance and breed them to rapidly develop lines that are better able to resist those pests.”
Boosting quality also remains the mission of alfalfa breeders such as Claessens.
“Our goal is to have cows produce more milk from the alfalfa they consume, either by increasing alfalfa’s digestibility or energy content so the microorganisms in their stomach can have more energy to process the protein,” she says. “By increasing the energy content, we can increase milk production from forages, increase protein content of the milk, and reduce nitrogen loss in the environment.”
Exciting new alfalfa varieties don’t just appear overnight. Claessens notes that breeding programs are expensive, and new sources of germplasm and funding are always being sought. It can take many years for a new alfalfa variety to hit the market.
More than GE
At this time, HarvXtra alfalfa with Roundup Ready Technology is available only to growers in Eastern Canada and is confined to the sale of seed for hay production. All seed production takes place in the United States.
“The reduced lignin trait is more important than the Roundup herbicide resistance, in my opinion,” says Mike Peterson, global traits lead for FGI. “The Roundup Ready trait is a nice add, but it’s not the main feature driving the sales of this product.
“The HarvXtra always comes first when we describe the product.”
GE alfalfa isn’t the only product FGI is working on. It’s also making strides with conventional alfalfa, an example being an attempt to offer stronger resistance to Anthracnose stem rot.
Anthracnose is caused by Colletotrichum trifolii. This fungus can attack leaves, but most characteristically attacks stems and crowns. While resistance has been built into many varieties, Peterson says it’s beginning to break down. The disease is rare in Western Canada, but it’s more prevalent in the Eastern United States and Eastern Canada.
“Even with Aphanomyces root rot, which has been around for over 20 years, the industry is finding there’s still a lot to be gained by breeding new varieties resistant to additional races of this important disease,” he adds.