Inter- and Intraplant Competition in Corn

Abstract

While competition for resources within and among plants is understood to affect yield per plant and thus per unit area, direct effects of crop management on plant competition are not always well understood. I narrowly define interplant competition here as a decrease in the amount of light intercepted per plant due to proximity to adjoining plants; such competition may or may not affect corn yield per unit area. Examples of management factors that influence interplant competition include uniformity of plant spacing, timing of plant stand loss, and plant population density. Intraplant competition effects are defined here as factors that affect internal allocation of photosynthate within the plant. I will restrict the discussion to plant damage effects that result in yield loss, and will relate this to reductions in light interception. I conclude that the goal of crop management is to have the corn plant set an adequate number of kernels, then to maximize the interception of light energy during the grainfilling stage in order to maximize yield.