RT Journal Article
SR Electronic
T1 A High-Resolution Cumulative Degree Day-Based Model to Simulate Phenological Development of Grapevine
JF American Journal of Enology and Viticulture
JO Am. J. Enol. Vitic.
FD American Society for Enology and Viticulture
SP ajev.2013.13066
DO 10.5344/ajev.2013.13066
A1 Daniel Molitor
A1 Jürgen Junk
A1 Danièle Evers
A1 Lucien Hoffmann
A1 Marco Beyer
YR 2013
UL http://www.ajevonline.org/content/early/2013/10/14/ajev.2013.13066.abstract
AB Common cumulative degree day models used to forecast grape growth stages are (i) often only of local validity, (ii) restricted to a rather limited number of phenological stages or (iii) do not take into consideration that the forcing effect of temperature is limited at higher temperatures. To overcome these problems, a new model was developed to simulate all 26 phenological stages [according to the BBCH (Biologische Bundesanstalt, Bundessortenamt und Chemische Industrie) scheme] of the Vitis vinifera L. variety Müller-Thurgau between budburst and harvest. Sixty time series of grape phenology from four European countries were used to set up and validate the model. The comparison of three cumulative degree day approaches (starting point of the model: budburst = BBCH 09) including one, two or three optimized temperature threshold values revealed that the incorporation of (i) an upper threshold temperature, above which a further increase of the temperature will not accelerate plant development and (ii) a heat threshold, above which a further increase of the temperature leads to a development deceleration, significantly improved the accuracy of the model compared to the cumulative degree day approaches previously published. The threshold triplet 5 °C, 20 °C and 22 °C for lower (base), upper and heat threshold temperature, respectively, allowed the most precise forecast. In 70.5 or 95.8% of the cases, phenological stages were correctly predicted in a range of 3 or 7 days (assuming daily mean temperatures of 20 °C), respectively, around the predicted cumulative degree day. The model can be used for a broad range of applications in viticultural research as well as in practical viticulture, for instance in the planning of tasks that depend on plant development, or as decision support tool for the timing of plant protection measures; moreover it could further be parameterized for other varieties.