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Tips for finding top-shelf alfalfa genetics

Dan Wiersma Published on 30 January 2015

Imagine cutting next year’s first crop of alfalfa and seeing a perfect stand of deep green, healthy alfalfa flowing through your haybine. Your neighbor says it’s the best stand of alfalfa he’s ever seen. It’s obvious that your silo will not hold your entire alfalfa crop.

Turning this fantasy into reality begins with something simple: choosing your alfalfa variety. Below are four key tips for finding top-shelf alfalfa genetics that can get you closer to that dream.

1. Know the company you keep
Connect with a reputable seed company that provides the best genetics and cares enough to help you make those genetics succeed on your farm.

Your alfalfa genetics supplier should do much more than deliver your seed. Look for a company that offers trustworthy information and helps you evaluate the potential of new products to fit your farm.

Turn your seed company representative into a trusted adviser who helps you find ways to cut costs and identifies value-adding opportunities for your forage operation.

2. Build a complete package
Not long ago, root rot diseases were driving growers away from planting alfalfa in wet soils. Today’s varieties deliver greatly improved alfalfa establishment and stand longevity. Selecting a disease and winter hardiness package reduces worries about high-risk weather and soil situations.

Alfalfa breeding has focused on advancing disease-resistant varieties since the 1970s. Today’s varieties have resistance to bacterial wilt, verticillium wilt, fusarium wilt, anthracnose, phytophthora and aphanomyces (race 1 and 2) root rots.

Each variety is evaluated using standardized tests and then characterized by disease resistance at five levels: susceptible, low resistance, moderate resistance, resistant and highly resistant.

A Disease Resistance Index (DRI) helps identify overall risk for the most common alfalfa diseases. The maximum score a variety can have is 35 (5 points per disease). While no alfalfa variety exhibits 100 percent resistance to a disease, top-shelf alfalfa varieties offer resistance above 50 percent for most diseases tested.

Winter hardiness of alfalfa varieties is another key factor in building your complete alfalfa package. In northern climates, winter hardiness is best defined as protection of the alfalfa crown against extreme cold exposure. In early alfalfa varieties, winter hardiness was closely related to fall dormancy.

More recent breeding advances changed this. Now, varieties with a fall dormancy (FD) score of 4 or 5 have very high winter hardiness levels. One advantage of FD 4 or 5 plants is their ability to produce extra forage growth, especially during the fall growing period.

In addition to disease resistance and winter hardiness, other factors may influence your variety decision. If your fields are prone to lodging, look for a variety bred for high standability.

To maximize forage quality or to extend your harvest window, consider a high-quality variety. When potato leafhopper pressures are an issue, or if you choose not to manage them chemically, select a leafhopper-resistant variety. Finally, if weeds challenge your stand’s establishment, consider alfalfa varieties resistant to glyphosate herbicide.

Know your risks and plan for them. Your best alfalfa package addresses all of your needs.

3. Demand proven performance
University yield trials and data from seed companies can help prove yield potential of alfalfa varieties. Small differences in yield can drive big differences in your bottom line. Choosing a variety that averages half a ton less than another is equal to choosing a corn variety that yields 20 bushels less per acre.

Many universities conduct alfalfa variety evaluation trials. Each university plants multiple locations and harvests four to five times per year for several years. While not as extensive as corn trial efforts, these alfalfa trials provide insights into top-performing genetics.

Look for varieties that consistently rise to the top of the tests across multiple years and locations. In addition, company-provided data (the data that drives breeding programs) can be used to confirm the performance and reliability of an alfalfa variety.

Testing “experimental” varieties is less reliable as a performance indicator than testing commercial products using seed from a commercial bag.

checking seed

4. Understand the bag’s tag
Learn to read your alfalfa seed tag to make good value choices. Seed-coating amounts can range as high as 35 percent to as low as 8 percent.

Seed germination rates can vary significantly. Obviously, the cost of seeding an acre of alfalfa can differ dramatically based on seed coating and germination rates alone.

Most university research verifies that optimum alfalfa stands can be established with or without heavy clay seed coatings. Clay or limestone-based seed coatings do not provide enhanced germination rates.

Stand establishment is best achieved with high-germ seed that has a seed-applied fungicide and nitrogen-fixing rhizobium. Avoid high levels of hard seed that do not contribute to stand establishment. Planting into a firm seedbed allows good seed-to-soil contact and helps ensure quick, uniform germination.

Remember: Getting the seed selection right is just the first step. To make the dream of a healthy, bountiful alfalfa crop a reality, start with top-shelf genetics.

Then drive your crop’s performance by planting for maximum seedling establishment, maintaining good weed and pest control and addressing the soil pH and fertility needs of the growing crop. Be sure to keep these tips in mind as you select alfalfa varieties for the coming year.  FG

Photo by Mike Dixon.

Dan Wiersma
  • Dan Wiersma
  • Livestock Information Manager
  • DuPont Pioneer