Justification: 

Oklahoma Alfalfa occupies  about 400,000 acres which generates a significant income to the state.  Traditionally, the best alfalfas in this area have been considered moderately dormant. Varieties with a significant amount of non-dormant germplasm in their pedigree sometimes have severe winter kill. The most persistent, high yielding varieties have only slightly less dormancy than those developed for the Midwest.  

Alfalfa Testing Personnel: 

Personnel in the Plant & Soil Sciences Department through the Oklahoma Agricultural Experiment Station  and Oklahoma Cooperative Extension Service, conduct alfalfa variety evaluations throughout the state to assist producers with decisions related to variety choices. Currently John Caddel has overall responsibility for this activity. 

Results: 

Detailed results and summaries of evaluations are published on the web at http://alfalfa.okstate.edu/var-test/alf-var.html and as extension publications each year. 

Varieties are tested in a wide array of environments and those that perform well consistently are included in a "recommended list" if they are marketed in Oklahoma. 

 
HOW DOES AN ALFALFA VARIETY GET ON THE RECOMMENDED LIST? 

To be placed on this list, an alfalfa variety must consistently yield well in several tests over several years, and its stand persistence must be good. Alfalfa seed distributors should assure OSU that seed will be available in Oklahoma.  If  seed is not readily available, a variety is not recommended. 
 
High yielding varieties with long stand life have acceptable levels of resistance to the important pests in Oklahoma.  Their multiple pest resistance is necessary for good performance.

  
HOW MUCH BETTER ARE THESE VARIETIES THAN OTHERS
THAT PRODUCERS CAN USE?

 

All  recommended varieties yield much better than the average in our tests. The yield advantage is usually about 10-15% compared to old Oklahoma commons and sometimes as much as 30% better than varieties that are not well adapted.  

Much higher yields are attainable, using new proven multiple-pest resistant varieties than using old varieties or seed from unknown sources. In addition to high yields, stands of the recommended varieties normally remain productive 2 to 5 years longer than  unimproved ones. 

 

Of the 50 to 100 varieties released each year, we test those that have potential for use in the state. They are sown in replicated small plots on research stations. Each plot is harvested and weighed at every cutting for at least 3 years.  

Personnel at Oklahoma State University responsible for alfalfa variety performance evaluations make every effort to conduct the best possible tests.   Individual tests are designed to detect forage yield differences of 5 to 10% (much smaller than can be seen). Yield differences of as little as 2-3% become important as we collect data from tests at different locations and years. When accumulated over years and averaged over several sites, yield differences among the best varieties are less than 2%.  The best varieties do, however, always differ from unadapted varieties and even some of the "so-called" new varieties. 
 

 

 
Announcement:

An invitation is sent to all known potential developers and marketers for alfalfa in Oklahoma during late July each year for trials to be sown in September. 

Entry Fee: 

Applicants pay a fee of $350 per alfalfa entry per site for proprietary varieties or experimental strains for a 3-year forage yield test.  Fees may increase to cover increased costs, and testers will be notified in the invitation. 

Testing fees payable to the Plant & Soil Sciences Department, O.S.U., should be received along with entry forms and seed several weeks prior to establishment of new tests. 

Seed: 

A 100-gram sample of alfalfa seed per site is required. 

Participants are requested to indicate the generation of seed submitted for testing (syn 1, syn 2, syn 3, etc.) for varieties and/or experimental strains. Purity and germination information should be provided, if possible. No lime coated seed.  Participants should also indicate if seed will be shipped directly from you or via a central collection site. If seed is to be shipped from a central collection site please inform them promptly. 
 
Description of tests: Entries will be planted in plots 5 meters long consisting of five rows, 15 cm apart, with a minimum of four (usually 6) replications. Herbicides will be used to control weeds as needed. Plots will be harvested when most entries are in bud or early bloom stage, 3 to 6 times per year depending upon the site. Normally yields are recorded for each harvest during 3 or 4 years. Observations on stand persistence, disease and insect damage, rate of regrowth, etc., will be taken when appropriate. When possible, plots will be maintained for 6 years. Years 4 through 6 will be primarily for persistence observations. 
 
Miscellaneous information: Alfalfa variety tests are available for inspection at any time mutually convenient to the Oklahoma Agricultural Experiment Station personnel and outside observers. Any questions related to these tests should be directed to John Caddel.  
 
E-Mail: john.caddel@okstate.edu 

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