The historic drought of the 2012 season is far from over, but one side effect of the drought is already predicted to extend into the next year on the scale not seen before.
With nearly 20 percent of contiguous United States enduring extreme and exceptional drought conditions and with 60 percent overall in moderate to severe drought or worse, according to the latest statistics by U.S. Drought Monitor, dramatic effects and costs of this natural disaster have already piled up.
The issue is not just about withering crops anymore. Farmers and herbicide makers are gearing for another, less obvious, consequence of the drought as the next growing season approaches: volunteer corn.
As drought escalated this year, large acreage of corn across the country failed and many farmers had to plow under their undeveloped fields. The by-product of this is that affected farmers will likely see a large emergence of “rogue” plants from the failed harvest whether they are making their switch to canola following their typical crop rotations or planting corn again..
Volunteer crops are considered to be weeds because they present farmers with the same problem as weeds. As noted by some weed specialists, volunteer crops:
reduce yields of the planted crop by competing for moisture, nutrients, and light, serve as hosts for diseases and insects that attack the planted crop, and interfere with harvesting operations. Volunteer crop plants also can reduce the quality of the harvested crop.
Some volunteer plants always come up post-harvest and farmers go through great lengths to harvest crops cleanly to minimize their emergence. Once volunteer plants emerge the solution typically involves the use residual herbicides early in the planting process and this year this practice will likely be implemented more extensively given the sheer magnitude of the what is expected. Ridding fields of volunteer crops, however, is made more complicated because so much of today’s corn crop is genetically engineered for herbicide resistance including Monsanto’s Roundup Ready corn varieties and Bayer CropScience’s LibertyLink corn with stacked herbicide resistance genes. Farmers clearing the fields, therefore, have to resort to herbicides different than the types the corn was genetically modified to withstand.
The impact on yield and increased early applications of herbicides will not be the only concern according to one integrated pest management specialist from University of Minnesota. Volunteer corn may allow more rootworms to survive between plantings and that has a potential of accelerating rootworm resistance to Monsanto’s Bt corn. With that as a possibility and with hard-to-kill rogue plants, reverting to row cultivation methods for pest control and even crop rotation may become a more effective pest management alternative on some fields.