Corn plants can overcommit to yield when environments are ideal through the pollination period and stress oc­­curs later. In a stressful environment, the large number of kernels place a high demand on the plant for sugars.

If photosynthesis, which produces sugars, is reduced because of stress, the kernels draw sugars from stalk tissue and deprive the roots of adequate nutrients. Cloudy weather following pollination is the most common stress...