Shopping for the best alfalfa varieties can be similar to buying a new truck. Buyers should compare the various brands, check prices and options, and check out the history reports.

“I’ve heard some people say the best way to choose an alfalfa variety is to go to a feed store or supplier and buy the cheapest variety,” said Dan Putnam, University of California Cooperative Extension forage specialist. “I highly recommend against this.”

Variety performance is more important than the seed price, says Putnam, who spoke at the 2010 Alfalfa, Forages, and Biofuels Field Day held at the University of California (UC) Desert Research and Extension Center (DREC) in El Centro, Calif., (Imperial County).

The DREC is the southern-most location for UC-sponsored alfalfa variety trials underway across California. The other locations include UC Davis and Kearney in the Central Valley, and at Tulelake and the Scott Valley in the intermountain region.

“Seed price is important at some level,” Putnam said. “If you have two equal varieties in performance then go after the cheaper seed. If you don’t consider variety performance then you may be losing yield potential.”

Alfalfa is the largest acreage crop in California; typically about 1 million acres. Acreage in 2010 is expected to drop to the 900,000-acre range, the lowest level since the 1940s. Declining acreage is tied to reduced alfalfa hay demand by cash-strapped dairies. Putnam says acreage may increase in the Imperial Valley this year due to alfalfa hay prices edging higher and improved foreign demand.

At what point is paying $2 more per pound for seed for an improved alfalfa variety worth it?

“About a tenth of a ton to two tenths of a ton increase in alfalfa hay yields is required to recover a $2 seed price increase,” Putnam told the farm crowd. “The first thing to ask an alfalfa salesman is how the variety performs — the characteristics, yields, and pest management characteristics.”

Putnam offered these suggestions to help choose the best alfalfa varieties.

• First, choose a group of high-yielding, certified varieties from relevant, multi-year trial results. Do not necessarily select the top-rated variety.

“The top one-third of the varieties are likely to become high-performing over time. Alfalfa is a perennial; be patient and see how the varieties perform over time.”

• Second, determine fall dormancy requirements and preference. The fall dormancy rating for low desert-grown alfalfa should be an 8 rating or higher. A 9 rating is the norm in desert production.

“The fastest way to gain higher yields, particularly in desert long-season environments, is to increase the fall dormancy rating. The plants will be more winter active, grow faster in the early spring, and provide higher yields per cutting.”

• Next, examine the variety’s pest resistance ratings. Determine the pests in the growing area. The stem nematode is not viewed as an important low desert pest, but Putnam suggests choosing a variety with some resistance.

“It’s similar to buying an insurance policy; you may not need a high resistance level every single year,” Putnam said. “In years when a bad infestation hits you are better off having the resistance protection.”

• Another factor to consider in alfalfa varieties is biotech traits. Monsanto’s Roundup Ready (RR) alfalfa is designed to tolerate the herbicide glyphosate. A judge in 2007 halted the sale of RR alfalfa pending completion of a USDA Animal and Plant Health Inspection Service environmental impact statement. Many expect RR alfalfa will be back on the market this year.

If RR alfalfa re-enters the market, Putnam is unsure whether RR alfalfa is a good fit for the Imperial Valley. Additional restrictions from seed companies and Monsanto exist for the distances between RR and non-RR alfalfa and seed production fields.

There is a major concern whether the Imperial Valley can successfully utilize the biotech trait while protecting the Valley’s major export seed and hay markets.

• Other key factors to consider include stand persistence and forage quality. A grower can sacrifice yield when quality is the top priority.

“If a seed person says they have a higher quality alfalfa variety, then the next question should be how well does it yield,” Putnam said. “If a ton of yield is sacrificed in favor of high quality, the grower should determine if the economics favor that.”

In many cases they do not, particularly in the Imperial Valley where some hay is yield-based for the horse market, not for quality hay.”

Putnam was asked if a variety can impact alfalfa quality. Yes, he said, but not as much as adjusting the cutting schedule.

“The cutting schedule is the most powerful way to impact quality rather than the variety,” Putnam said. “You can cut five days early and get the same or better impact on quality.”

Varieties with a higher fall dormancy rating and a faster growing period can increase quality by improving levels of protein, total digestible nutrients, and the leaf-to-stem ratios. Decreased dormancy almost always reduces yields.

email: cblake@farmpress.com