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Posted 19 November 2007. Forage and Grazinglands. Unprecedented Volunteer Corn: Good for Livestock, Bad for Wheat University of Illinois at Urbana-Champaign. www.aces.uiuc.edu Urbana-Champaign, Illinois (November 1, 2007)--Wow, have you ever seen as much volunteer corn like that present in fields this fall? The exceptional growing season combined with a very dry, warm fall caused early maturing corn to be harvested earlier and drier than usual, and the low moisture content of the seed caused more breakage and loss as it flew out of the combine. Corn seed on the ground apparently had enough soil to seed contact and moisture to germinate prolifically. Despite this corn yields were great around the area.
From a livestock standpoint the volunteer corn, and possibly soybean in some fields, could be a wonderful forage opportunity coming at a time when forage is in short supply. Dean Oswald, University of Illinois Extension Educator for Animal Systems, says, "The volunteer corn can add nutritional value to the corn stubble." However, in drought stricken areas beware of the potentially high levels of nitrate that could build up in volunteer corn under dry conditions. If animals are eating a blended diet of other grasses, corn stubble, and hay along with the volunteer corn, high nitrate levels in the volunteer corn may not be a concern. However, getting the volunteer corn tested at a forage lab for nitrate levels is the easiest way to determine if nitrate is a problem. Oswald adds, 'Since soybean is a legume, volunteer soybean in fields would add high quality feed for grazing animals, because typically soybean residues are less nutritious than corn residue for ruminant animals.' From a wheat disease standpoint, the large amounts of volunteer corn could be a detriment to wheat production because it becomes a food source for wheat curl mite that carries wheat streak mosaic virus. Infection of winter wheat usually happens in the fall when volunteer wheat, grassy weed hosts, or volunteer corn plants are present when adult mites are looking for green plants to feed and lay eggs. Volunteer wheat is the mite's first choice, but if large amounts of volunteer corn are still green the corn could easily become infested with mites carrying wheat streak mosaic virus. Wheat fields planted next to corn fields with large amounts of volunteer corn are particularly susceptible. The warm, dry fall we have been experiencing also favors the survival, reproduction, and movement of the wheat curl mite. Waiting to plant wheat until after the Hessian fly free date helps, but this year the warm, dry weather and amount of volunteer corn may make this management practice ineffective. To check for the presence of the wheat curl mite, a hand lens is needed to see the small, white, cigar-shaped wingless adult. When large populations of mites are present they cause the edges of the wheat leaves to curl inward. Aphids are another insect whose populations may be favored by volunteer corn this fall. Many types of aphids, including the corn leaf aphid, carry the barley yellow dwarf virus (BYDV) which persists in nature in small-grains, corn, and many other perennial and annual grasses. The spread of BYDV from plant to plant and from field to field depends entirely on aphid movement. Aphids surviving on volunteer corn could easily move into nearby germinating winter wheat and transmit BYDV. Barley yellow dwarf virus has the potential to cause more severe damage to wheat when infections occur in the fall. Contact: |
