Growth and physiological trait variation among corn hybrids for cold tolerance

Global food demand has risen continuously because of increasing population with greater food and energy needs. Corn production, however, is constrained by current and possible increased future variability in the weather. Earlier planting is a strategy for U.S. Mid-South corn producers to avoid typical summer droughts. However, planting early will increase the likelihood of seedlings exposure to cold temperatures. The objectives of this study were to evaluate corn hybrids planted when the conditions are desirable followed by low and moderately low temperatures to assess the variability among the vegetative and physiological parameters and to classify hybrids into different cold tolerant groups. Twenty one commercially-grown hybrids were subjected to three day/night temperature treatments; 29/21 °C (optimum), 25/17 °C (moderately low), and 21/13 °C (low) from 15 d after planting (DAP) for plants grown at optimum temperature. Shoot, root, and physiological parameters were measured, 32–34 DAP. Significant dif...