Forage Cuttings
(from the Autumn "Haymaker" newsletter)

Mike Rankin
Crops and Soils Agent
University of Wisconsin - Extension

StandFast Alfalfa

        There has not been much in the way of alfalfa genetics news in the past 20 years to get overly excited about.  The lack of progress in yield enhancing traits has been well documented.  The trend seems to be slowly breaking.  Last year, Dairyland Seeds released their first generation of hybrid alfalfas, which if nothing else seem to be consistent in their ability to hold high yields across a wide range of environments.   Next year, a new trait will be introduced called "StandFast".  Claims are that these varieties will exhibit superior standability (less prone to lodge) and faster regrowth.

        The StandFast varieties, developed by Cal/West Seeds, were derived from European parental plants.  Evidently, high standability scores are a requirement in Europe.  The varieties have been initially tested at the University of Nebraska and Penn State University.  The theory, of course, is that better standability translates to higher yields because more of the plant is actually cut and harvested.  In fact, cutting height research confirms that producers can add 0.25 to 0.50 tons per acre by harvesting just one inch more of the stem over the course of a season.  Researchers feel the regrowth ability of the StandFast alfalfas is at least as good as other faster regrowth varieties on the market. Like hybrid alfalfa, time will be the true test of the StandFast types.  Because Cal/West is strictly a breeding company, you will likely see the StandFast trait in variety offerings from several different seed marketers.

Update on Roundup Ready Alfalfa

        As long as we're on the topic of new alfalfa traits, it appears that Roundup Ready alfalfa is still being targeted for approval in 2004.  At the recent Pest Management Update Meeting, Jerry Doll, UW Extension Weed Specialist, reported on results from his 3-year study with RR alfalfa.  He summarized the results as follows:

• Excellent crop tolerance (maximum of 9 pt/acre applied

• Excellent weed control, including dandelion

• Can achieve weed-free alfalfa for the duration of the stand with no risk of crop injury and great flexibility in application timing.

        There will be some management considerations to be worked-out with RR alfalfa.  First, it will obviously take something other than glyphosate to kill stands at the end of the rotation (for example, 2,4-D and dicamba).  Additionally, if there are other perennials like quackgrass in the stand, glyphosate may still be needed to knock these out.  If producers choose to kill stands with nothing other than tillage and follow with RR soybeans or corn, dealing with any alfalfa that does grow back will be more problematic (killing volunteer alfalfa in soybeans is currently difficult enough).  Finally, there is the issue of glyphosate resistance developing by weeds where producers choose RR crops throughout the rotation.

Raptor versus Pursuit for Weed Control in Direct-seeded Alfalfa

        The availability of Raptor and Pursuit for weed control has made life in the direct-seeded alfalfa lane much more bearable.  Simply put, there are a lot more producers direct seeding alfalfa than there were just a few short years ago.  Both post-emergence products are effective, but there are some differences as the following chart created by Jerry Doll points-out: 

Forage Testing…….decisions, decisions

        Considerable time and effort have been expended to inform producers and industry representatives of the new changes in the world of forage testing.  New testing procedures for neutral detergent fiber digestibility (NDFD) have led to different methods of figuring parameters such as total digestible nutrients (TDN) and Relative Forage Quality (RFQ).  There are a number of different levels of forage testing from which a producer and/or feed nutritionist can choose.  Effectively, it breaks down like this from low to high:  

1.  Basic NIR test for parameters such as CP, ADF,NDF, minerals, and determination of RFV.  Not a good choice for balancing feed rations but perfectly fine for a quick comparison of potential differences between two forages.

2.  NIR test to determine CP, ADF, NDF, NDFD, TDN, etc. and determination of RFQ.  Better than the basic test with more precise energy values but requires additional day for oven-drying samples.

3.  Wet chemistry / NIR combination.  Wet chemistry used to increase precision of NDFD, ash, and mineral measurements.  Best for feed ration balancing and troubleshooting problems. 

        The format of these tests will vary between forage laboratories.  Now, more than ever, it is important to consult with your nutritionist to determine the most appropriate forage and feed testing protocols.  It's easy to live with more complicated as long as the information you receive is more precise.  Such is the current state of forage testing.