A Point to be Made With 'Pointer'

Mike Rankin
Crops and Soils Agent
University of Wisconsin - Extension

        How much time and effort does the average forage producer put forth into selecting an alfalfa variety?  I'm guessing it's not whole lot.  There are several reasons for this.  First, reliable yield data is hard to obtain.  Heck, unreliable yield data is hard to obtain.  Certainly there are the University of Wisconsin alfalfa variety performance results but the list of replicated yield data pretty much ends after that.  Many companies do their own variety performance testing but this information is generally not made public.  By comparison, there are enough corn and soybean yield data available each year to wallpaper the milk house walls.

        In the case of alfalfa, there are many other considerations to be made in addition to yield.  There is forage quality, disease resistance, stand persistence, maturity, and insect resistance.  The reliable data for these secondary factors is even more scarce than that for yield.  Hence, at some point it all becomes too mind boggling and the tendency is to make a decision based on seed company loyalty, unsubstantiated claims, price, or the fact that you need to buy something from your 3^rd cousin.  All of this is very understandable.

        The point to this discussion is that making a poor alfalfa variety selection choice carries with it some severe economic consequences.  Most farmers wouldn't consider giving up 8 bushels of corn per acre to plant one hybrid over another (all other factors being equal). Yet that amount of corn has approximately the same gross value as 0.25 dry matter tons of alfalfa (even less tonnage in a tight forage market).  Furthermore, with a crop like alfalfa you live with the decision and loss for 3 to 5 years. 

OK, so what do I do?

        The rules for alfalfa variety selection can be made relatively simple.  Most of the new alfalfa varieties hit the market with a near complete package of disease resistance.  It's almost become a non-issue unless you know that a specific problem like Race 2 Aphanomyces will limit establishment and plant survival.  Variety performance data is very limited for forage quality and only somewhat better for stand persistence.  The data is generally reliable, but starting with one of these criteria will severely limit the variety selection pool.  There is really only one place to start when making your selections ---- those varieties that rank consistently high in yield over a number of locations.  Not necessarily the best at every location, but consistently in the top one-third of varieties tested at a given location.

Why not just pick the top performer at the Fond du Lac site in 2000?

        Whether we're talking about corn, soybeans, alfalfa, or petunias, it's a hard concept to understand that the best yield data is not just what was measured outside your own barn door in a given year.  This has been proven over and over again by using historical yield data. Locations are really environments.  Although locations don't change from year to year, environments at the same location always undergo annual changes.  If you make selections based on one location and one year, chances are heavily weighed that you won't be making the best selection.

A case in 'Pointer'

        At long last we get to the "point" of this article.  Let's look at the performance of a variety named 'Pointer' in the 2000 UW alfalfa variety performance trials.  This variety was seeded at three different locations in 1999.  Its performance information is presented in Table 1.  

         Depending on location, a person draws very different conclusions about 'Pointer'.  At Fond du Lac, it's the absolute best finishing 1^st of 38 varieties and over 0.5 tons D.M. above the trial mean.  'Pointer' is nearly dead center average at Arlington but finishes only above Vernal at Marshfield with a yield that is well below the trial mean.  Looking at any single location gives a very different perspective on this variety.  There simply is not enough information yet to know if 'Pointer' is the varietal equivalent of the Yankees, Angels, or Cubs.

        In summary, alfalfa variety selection is important and carries with it significant economic consequences.  Pick varieties that consistently yield in the top one-third of trials where it has been tested.  After doing this, check other criteria such as disease/insect resistance, forage quality and stand persistence.  Don't make selections based solely on data from one year and one location.