Abstract
Daily totals or daily averages are convenient to work with and provide a first sound impression of the climatic factors. For example, the development rate of a crop can be estimated quite well by making use of the average air temperature. After all, it is not possible to measure accurately the stages of development from day to day, which means that the effect of temperature must be integrated over at least a week. It is then usual to make use of the concept of ‘temperature sum’ or ‘degree-days’. This value is calculated as the integral of the value with which the (average) temperature exceeds a certain lower threshold (e.g. 5 °C), below which no development occurs at all. This procedure implicitly assumes a linear response above the lower threshold. Also the sum of radiation (possibly modified by the fraction intercepted, see Eqn 2.7) is often used.
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© 1994 Springer Science+Business Media Dordrecht
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Goudriaan, J., Van Laar, H.H. (1994). Climatic factors. In: Modelling Potential Crop Growth Processes. Current Issues in Production Ecology, vol 2. Springer, Dordrecht. https://doi.org/10.1007/978-94-011-0750-1_3
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DOI: https://doi.org/10.1007/978-94-011-0750-1_3
Publisher Name: Springer, Dordrecht
Print ISBN: 978-0-7923-3220-6
Online ISBN: 978-94-011-0750-1
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