Winter 2009 - 2010

This fall, many farmers observed corn stalks that were soft or broke easily. There are many possible causes, with diseases, insects, and K malnutrition as primary candidates. Stalk breakage and lodging at or near corn harvest are not solely diagnostic of a K deficiency, but are consistent with it. Farmers and advisers may want to watch soil test levels and crop development next season. Delays in leaf emergence, silking, and tasseling have all been shown to be caused by K deficiency. Such delays can result in higher grain moisture at harvest. Because subtle changes in crop development are hard to detect, putting out a strip in the field where K has been applied in a sufficient quantity can serve as a needed reference against which comparisons can be made. Farmers and advisers are encouraged to examine nutrient budgets for the last few seasons to see if nutrient withdrawals from crop harvest have exceeded K applications. If so, plans should be made to ensure soil fertility and nutrient applications do not become limiting.