By Bill Mahanna and Ev Thomas
In our last column in the February 10, 2011, issue we addressed corn silage blends. Now let's turn our attention to forage seed blends. For the purpose of this discussion, forage blends will be products containing a specific species, such as alfalfa, rather than a "pasture blend" containing multiple legume and grass species.
When considering the value proposition of a forage blend, most growers understand the need to critically compare price against seed purity and quality. Forage blends from most reputable seed suppliers contain relatively high-quality seed and not "floor sweepings" as some people may think. However, depending upon the supplier, blends are certainly more variable and can range from high germination and high purity to products with lower germination (often older seed) and low purity.
Two main sources
At one end of the seed trade there is "common seed" produced by individual farmer-seed growers. In some crops like alfalfa, clovers, and forage grasses, you can literally find "brown-bag" VNS (variety not stated) products produced by individual farmers who allow a field to go to seed. This is not strictly legal if it involves patented varieties and certainly not with varieties containing proprietary transgenic traits. For these reasons, this source of VNS seed has dwindled to near zero in the era of transgenic crops like corn and soybeans. In forage grasses and legumes, this "farmersource" seed generally finds its way into the market through seed brokers. Rather than the traditional VNS "brown-bag," these products often get sold today in fancy bags, as micro-brands marketed through retailers and companies possessing no seed production, conditioning, or bagging capability.
At the other end of the seed trade are a few major brands that offer blends, typically from their own genetics and produced through their normal production channels. These blends are sold without stating the variety which allow seed companies the option of selling end-of-lifecycle products or excess inventory due to overproduction or lost performance. Blends can also include excess parent seed, experimental varieties that don't advance to commercial status, or inventory that may not meet purity specifications for outcrosses or self-fertilized plants due to failed isolation standards. For all these reasons, blends can vary considerably from lot to lot, and almost certainly from year to year.
Some seed companies have built name recognition around premium blend products. These higher-priced blends may vary in variety but have a consistent branded name with a guaranteed specification for some trait such as a minimum DRI (disease resistance index) or having a stated level of a known variety. Premium blends reduce the company's options for inventory management but offer growers more information about performance.
Be cautious when a premium blend approaches the price of a pure variety. Unless you know all the varietal components of a blend, and have a specific reason for their inclusion levels, you will likely be better off purchasing a pure variety that fits your specific needs.
Growers should rely on the bag tag to evaluate any seed purchase. The tag will indicate the crop species, germination level, crop purity, and weed seed content. Discerning growers should look at the seed tag for germination levels and adjust seeding rates accordingly. Some blends are sold with descriptive information that narrows the range of variation, such as stating if the product is a "fall-dormant" or "nondormant" alfalfa blend.
More reputable seed suppliers take extra measures to ensure that blends meet minimum disease resistance criteria for the specific region the blend will be sold. Beware of blends with a tag showing lesser crop purity. If the tag says there is 3 percent "Other Crop," don't be surprised if your new alfalfa seeding looks like a mixed stand.
In summary, consider blends when you trust the reputation of a company and their seedsmanship. Blends may have suitable performance for short rotations or field situations where specific pest resistance traits or performance of a pure variety are not needed or valued. Carefully consider the economic impact of greater variability and reduced performance of blends in fields seeded down only every three to five years. Pay attention to seed tag information to help set your expectations for crop purity, germination level, and performance. Read company literature and websites for additional clues about adaptation and performance. Expect to pay a little more for premium blends that offer stated traits or varieties you know and value. Don't overpay for a blend when you can select a specific variety with traits you need for your individual fields and specific growing environment.
This article was originally published in the March 2011 Hoard's Dairyman issue, and is reproduced with their permission.