Degree-Day Models

Abstract

The development of plants and Poikilothermic (cold-blooded) animals is highly dependent on temperature. It has been said that “the hotter it is the faster they grow.” This is true, up to a point, where higher temperatures retard or even stop development. Temperature-driven models are available for a large number of plants such as corn, cotton, alfalfa, and several vegetables as well as many pests of these crops. These have had several practical impacts. For example, when adverse weather conditions delay planting, a farmer may reference historical data to assess the probability that a long-season variety will have ample time to mature before a killing freeze. If it is unlikely that the crop will have time to mature, he may consider planting a shorter-season variety or an alternative crop.