Burrus has received some customer reports related to non-GM harvest issues. Simply stated, the type of “border harvest” needed to reach an acceptable non-GM purity has been atypically wide in 2014. In one case, the grower had to shave off 4 to 5 times the border area commonly needed. Such issues apparently are occurring in proximity to neighboring GMO corn.
What should you do? Because the issue appears to be pollen drift into non-GM fields, Burrus strongly recommends that non-GM growers harvest outer rows and deliver that corn until they eventually hit acceptable purity. We simply cannot predict where that line is in each field, but sampling each field should paint the needed picture. Burrus also strongly recommends that growers not toss everything in the bin before conducting the step above. If contamination truly was exceptional (for reasons listed below in this article), the risk of contaminating or losing the non-GM premium on an entire bin of corn is simply not worth the additional corn in storage. Pick and deliver until you hit purity, then start thinking about storage.
Why do growers have to go deeper into fields before they reach acceptable purity?
1.) How much GM pollen has been present in 2014? In a July 2014 report, the USDA Economic Research Service stated that herbicide tolerant crops represented 89 percent of US corn acreage. Corn with at least one insect trait represented 80 percent of US corn acreage. In total, 93 percent of the US corn acreage consisted of some kind of traited product. Increase the relative number of GMO corn near a non-GM field, and the "contamination risk" of pollen contamination increases as well.
2.) There must be a relatively smooth “nick” between the undesired/donor/GM corn and the non-GM crop. “Nick” refers to pollen being present when silks are present. In Illinois, it often takes about 8 days to go from 50 percent planted to 75 percent planted (USDA – NASS), but in 2014, growers were able to complete planting in about 5 days. In addition, alot of similar maturity corn was planted at the same time. It usually takes about 8.5 days for Illinois corn to go from 50 to 75 percent silk. In 2014, silking occurred within 5 days. In other words, many of the same corn maturities began to silk and shed pollen at the same time. GMO corn was eager and much more able to provide contaminating pollen in a “timely fashion.”
3.) Environmental factors, such as cool conditions, increased the viability of pollen. Corn pollen can last for a while (hours) before it “must” come into contact with silk, but it doesn’t last forever. Cool conditions increases the viability of pollen, which provides more opportunity for contamination.
4.) Getting pollen to travel far requires the correct environment as well. Most corn pollen drops relatively close to the plant from which it originated (some resources say about 99 percent falls within a couple dozen feet of the plant). However, this does not mean all corn pollen falls within that distance. A percentage or two of that pollen will always drift further. The distance this pollen moves can total an additional several feet to several dozen feet. The microenvironment, wind in particular, will determine how far pollen drifts. The 2014 storm events allowed pollen to really move around!
– and you get increased GM contamination risk to non-GM corn in 2014!
(Matt Montgomery, THE Burrus Sales Agronomist)