May 7, 2007
Wet Weather Concerns
Applications of Herbicides and Nitrogen
UAN solution will burn corn leaves if it is applied after corn emergence.
Usually this will not result in any yield loss with rates of 60-90 lb N/A on
small corn. However corn yield reductions can occur if the nitrogen is used as
a carrier for an herbicide application after corn emergence. The nitrogen and
herbicides should be applied separately to minimize the risk of injury. See the
following article from the last month’s ICM Newsletter for more details:
Planting Under Less Than Ideal Conditions
Many growers still have some of their corn and most of their soybeans yet to plant. Planting when the soil is too wet can lead to a lot of problems later in the growing season, including “stress-induced K deficiency” in corn from poor root growth due to sidewall planter compaction. Although it is always best to wait until soil conditions are ideal for planting, with the current wet conditions and more rain in the forecast it is likely that some planting will be done this month under less than ideal conditions. One way to try to minimize the problems caused by planting under somewhat wet conditions is to lessen the down spring pressure on both the planter closing wheels and depth gauge wheels to try to reduce the compaction caused by the planter. See Mark Hanna’s article in the ICM Newsletter for more details:
Note: See also Virgil Schmitt’s update on Alfalfa Weevil, Corn planting, Black Cutworms, Corn Flea Beetles, and Bean Leaf Beetles at http://www.extension.iastate.edu/Pages/eccrops/cu070507.html.
If you have any questions, please feel free to contact the Iowa State University Extension Office.
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