Issue No. 1, Article 9/March 24, 2006
Promotions for a "Nontraditional" Product
We have received a number of questions in recent weeks about a specific product called "X-Tra Power," which is a mixture of chelated micronutrients (magnesium, copper, manganese, and zinc), along with "growth-supporting co-factors," sold by Stoller USA, a company in Texas. While many such products are marketed, the campaign to sell this one includes citations that the "University of Illinois" found some rather large increases in corn yield from using this product in trials. The company Web site cites Dr. Wayne Pedersen of the U of I as having gotten 13.3 and 30.0 bushels per acre yield increase on corn in 2004 and 2005, respectively, from using X-Tra Power at a quart per acre in-furrow.
I have tested this product as a foliar application at Urbana, and Eric Adee tested it as a starter application at Monmouth in 2005. These results are not part of the advertising literature, but neither showed a significant yield increase from this product. So there are some positive results and some less-positive ones, which is typical for such inputs. We have no reason to disbelieve the positive results that have been reported, but we clearly lack access to all results, including those that showed little or no response. Not having all data means that we have no way to know what an "average" expectation should be from using this product.
This lack of complete information is the norm with products such as these, so the decision on whether or not to use such products is based less on neutral information than on trust in the company that sells them and in our own instincts. There is apparently a guarantee with this particular product, in which the purchase price will be refunded if the material fails to pay for itself. This is to be measured by leaving an untreated strip in the field. Such an approach is a little skimpy on statistical validity, though unless the strip is chosen with a certain outcome in mind, that risk is shared by the producer and the company. Such a guarantee moves some risk from the producer to the company, which can be helpful if refunds are made in cash and less helpful if "refunds" are in the form of more product, especially more of the same product that just showed itself to be ineffective.
We know that micronutrients are necessary for plants, even though many trials have shown that soils usually supply enough of these elements so that we don t need to add them. But given the limited neutral information on such a product, how do we make the decision to use it or not? Let's first keep in mind that there have been a lot of very high yields in Illinois in recent years and that many of these were in fields where such products were not used--there is certainly no indication that high yields require such inputs.
If producers are using micronutrients routinely and are convinced that they need them, then such a product should be compared to other sources in terms of price. (Availability of chelated versus nonchelated micronutrients is a separate issue, which we'll leave for another time.) In this case, we can also be reasonably confident that the input will not produce a loss in yield. This is helpful information to use in such decisions, in that it means our exposure is limited to the cost of the material.
It is difficult to imagine that a lot of fields have another 15 to 30 bushels just waiting to be "released" by the use of such inputs, but we have no basis to rule out the possibility of this happening. On the other hand, hundreds of trials have been done on inputs like this, and the majority of such trials have shown no effect. While we need to stay open-minded about such products, it is also helpful to be skeptical. In this case, one way such skepticism might be put into practice is to put the X-Tra Power on with one side of the planter and not with the other side, keeping things like starter the same on both sides. The yield monitor can be used to take yields, as long as there is a clear record (a PVC marker stake is helpful) of which side of the planter was treated.
Such results will not answer the question for every field and for all time, but it s really the only way to get a direct answer for a given field in a given year. In the same way that we should remain skeptical about the usefulness of such a product, we should also remain open to further testing if a first, single test shows no yield increase or an increase not large enough to pay for the product. If you want more specific suggestions about such a test, feel free to contact me.--Emerson Nafziger