Some corn fields this past week have begun to shut down operations prematurely. In some cases, the premature death is related to severe disease stress (see Don Scott's article P&C Newsletter, 9/1/95). In many other cases, however, the plants have simply 'given up the ghost' due to cumulative effects of this summer's heat stress, coupled in some areas with fairly severe moisture deficits.
Many of these fields (maybe all) were those same fields that we all abused last spring by working and planting fields that were too wet to be in. The subsequent poor root establishment, especially shallow root development, resulted in plants that were vulnerable to extreme weather patterns.
One of the extremes that most of the state suffered from this year was the unusually abundant number of days with temperatures in the 90's. Several days of such temperatures usually don't impact corn growth and development very much. However, weeks and weeks of such temperatures eventually takes its toll on plant health as well as dry matter accumulation.
Plants suffering from such stress struggle to complete grain fill before they 'give up the ghost'. In doing so, they often resort to cannabilizing the carbohydrates and nutrients from the leaves and stalks in order to fill the grain. In response to decreased carbohydrate levels in the lower stalks and roots, the plant often becomes more susceptible to the ever-present root and stalk rot organisms. Growers should walk these fields during the next few weeks, monitor the stalk health, and adjust harvest strategies accordingly to manage fields where stalk lodging may be a big problem.