Standard Article

Degree Day Method


  1. Carlos D. Messina

Published Online: 15 APR 2005

DOI: 10.1002/047147844X.me76

Water Encyclopedia

Water Encyclopedia

How to Cite

Messina, C. D. 2005. Degree Day Method. Water Encyclopedia. 4:197–199.

Author Information

  1. University of Florida, Gainesville, Florida

Publication History

  1. Published Online: 15 APR 2005


An adequate description and prediction of plant development is critical for understanding plant growth and its responses to the environment. Only then we can assess the impact of a changing environment on plant productivity and survival, understand plant adaptation, design adequate agricultural production systems, and optimize natural resources management. Of particular importance for water resource management are the effects of plant ontogeny on plant water use and productivity throughout the regulation of leaf area. This determines the patterns of plant water demand and the partitioning between transpiration and evaporation components. Therefore, plant development dictates the selection of cultivars that best fit the water availability patterns under dryland conditions, and the amount, frequency and timing for irrigation otherwise.


  • degree days;
  • photothermal units;
  • physiological day;
  • growing degree day;
  • plant development;
  • photoperiod;
  • day length;
  • crop model