International Journal of Biometeorology

, Volume 60, Issue 8, pp 1123–1134 | Cite as

Growing degree hours - a simple, accurate, and precise protocol to approximate growing heat summation for grapevines

Original Paper


Despite its low accuracy and consistency, growing degree days (GDD) has been widely used to approximate growing heat summation (GHS) for regional classification and phenological prediction. GDD is usually calculated from the mean of daily minimum and maximum temperatures (GDDmm) above a growing base temperature (T gb). To determine approximation errors and accuracy, daily and cumulative GDDmm was compared to GDD based on daily average temperature (GDDavg), growing degree hours (GDH) based on hourly temperatures, and growing degree minutes (GDM) based on minute-by-minute temperatures. Finite error, due to the difference between measured and true temperatures above T gb is large in GDDmm but is negligible in GDDavg, GDH, and GDM, depending only upon the number of measured temperatures used for daily approximation. Hidden negative error, due to the temperatures below T gb when being averaged for approximation intervals larger than measuring interval, is large in GDDmm and GDDavg but is negligible in GDH and GDM. Both GDH and GDM improve GHS approximation accuracy over GDDmm or GDDavg by summation of multiple integration rectangles to reduce both finite and hidden negative errors. GDH is proposed as the standardized GHS approximation protocol, providing adequate accuracy and high precision independent upon T gb while requiring simple data recording and processing.


GDD GDH Rectangular integration Finite error Hidden negative error 



The research was partially funded by the California State University-Agricultural Research Institute (CSU—ARI). The author thanks Dr. AH Sabuwala and Mr. KL Gu for a useful discussion on rectangular integration. The author also thanks Drs. AH Sabuwala, S Gu, K Kurtural, S van Zyl, and D Zoldoske as well as Mr. S Grant, G Dervishian, and KL Gu for a helpful review of the manuscript.


  1. Allsopp PG (1987) Estimating day-degrees from daily maximum-minimum temperatures: a comparison of techniques for a soil-dwelling insect. Agric For Meteorol 41:165–172CrossRefGoogle Scholar
  2. Amerine MA, Winkler AJ (1944) Composition and quality of musts and wines of California grapes. Hilgardia 15:493–675CrossRefGoogle Scholar
  3. Buttrose MS, Hale CR (1973) Effect of temperature on development of the grapevine inflorescence after budburst. Am J Enol Vitic 24:14–16Google Scholar
  4. Burden RL, Faires JD (2011) Numerical analysis. 9th ed. Brooks/Cole, Cengage Learning, BostonGoogle Scholar
  5. Cesaraccio C, Spano D, Duce P, Snyder RL (2001) An improved model for determining degree-day values from daily temperature data. Int J Biometeorol 45:161–169CrossRefGoogle Scholar
  6. DeGaetano AT, Knapp WW (1993) Standardization of weekly growing degree day accumulations based on differences in temperature observation time and method. Agric For Meteorol 66:1–19CrossRefGoogle Scholar
  7. Gladstones J (1992) Viticulture and environment. Wine titles, Adelaide, 310 ppGoogle Scholar
  8. Gu S, Jacobs SD, McCarthy BS, Gohil HL (2012) Forcing vine regrowth and shifting fruit ripening in a warm region to enhance fruit quality in ‘Cabernet Sauvignon’ grapevine (Vitis vinifera L.). J Hortic Sci Biotech 87:287–292CrossRefGoogle Scholar
  9. Huglin P (1978) Nouveau Mode d’Évaluation des Possibilités Héliothermiques d’un Milieu Viticole. C.R. Acad Agric France 64:1117–1126Google Scholar
  10. Jackson DI, Lombard PB (1993) Environmental and management practices affecting grape composition and wine quality—a review. Am J Enol Vitic 44:409–430Google Scholar
  11. Jones GV, Davis RE (2000) Climate influences on grapevine phenology, grape composition, and wine production and quality for Bordeaux, France. Am J Enol Vitic 51:249–261Google Scholar
  12. McIntyre GN, Kliewer WM, Lider LA (1987) Some limitations of the degree day system as used in viticulture in California. Am J Enol Vitic 38:128–132Google Scholar
  13. Molitor D, Junk J, Evers D, Hoffmann L, Beyer M (2014) A high-resolution cumulative degree day-based model to simulate phenological development of grapevine. Am J Enol Vitic 65:72–80CrossRefGoogle Scholar
  14. Moncur MW, Rattigan K, Mackenzie DH, McIntyre GN (1989) Base temperatures for budbreak and leaf appearance of grapevines. Am J Enol Vitic 40:21–26Google Scholar
  15. Nendel C (2010) Grapevine bud break prediction for cool winter climates. Int J Biometeorol 54:231–241CrossRefGoogle Scholar
  16. Oliveria M (1998) Calculation of budbreak and flowering base temperatures for Vitis vinifera cv. Touriga Franscesa in the Douro region of Portugal. Am J Enol Vitic 49:74–78Google Scholar
  17. Parker A, de Cortazar-Atauri I, van Leeuwen C, Chuine I (2011) General phenological model to characterise the timing of flowering and veraison of Vitis vinifera L. Aust J Grape Wine Res 17:206–216CrossRefGoogle Scholar
  18. Purcell LC (2003) Comparison of thermal units derived from daily and hourly temperatures. Crop Sci 43:1874–1879CrossRefGoogle Scholar
  19. Rawworth DA (1994) Estimation of degree-days using temperature data recorded at regular intervals. Popul Ecol 23:893–899Google Scholar
  20. Roltsch WJ, Zalom FG, Strawn AJ, Strand JF, Pitcairn MJ (1999) Evaluation of several degree-day estimation methods in California climates. Int J Biometeorol 42:169–176CrossRefGoogle Scholar
  21. Snyder RL, Spano D, Cesaraccio C, Duce P (1999) Determining degree-day thresholds from field observations. Int J Biometeorol 42:177–182CrossRefGoogle Scholar
  22. Scarpare FV, Filho JAS, Rodrigues A, Reichardt K, Angelocci LR (2012) Growing degree days for the ‘Niagara Reseda’ grapevine pruned in different seasons. Int J Biometeorol 56:823–830CrossRefGoogle Scholar
  23. Tarara JM, Blom PE (2009) Modeling seasonal dynamics of canopy and fruit growth in grapevine for application in trellis tension monitoring. Hortscience 44:334–340Google Scholar
  24. Watson DM, Beattie GA (1995) Effect of weather station logging interval on the precision of degree-day estimates. Aust J Expt Agric 35:795–805CrossRefGoogle Scholar
  25. Williams DW, Williams LE, Barnett WW, Kelley KM, McKenry MV (1985a) Validation of a model for the growth and development of the Thompson seedless grapevine. I. Vegetative growth and fruit yield. Am J Enol Vitic 36:275–282Google Scholar
  26. Williams DW, Andris HL, Beede RH, Luvisi DA, Norton MVK, Williams LE (1985b) Validation of a model for the growth and development of the Thompson seedless grapevine. II. Phenology. Am J Enol Vitic 36:283–289Google Scholar
  27. Winkler AJ, Cook JA, Kliewer WM, Lider LA (1974) General viticulture—revised and enlarged edition. University of California Press, Berkeley and Los AngelesGoogle Scholar
  28. Worner SP (1988) Evaluation of diurnal temperature models and thermal summation in New Zealand. J Econ Entomol 81:9–13CrossRefGoogle Scholar

Copyright information

© ISB 2015

Authors and Affiliations

  1. 1.Viticulture and Enology Research CenterCalifornia State UniversityFresnoUSA

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