title: The Book of Vinesprouts of Kőszeg (Hungary): a documentary source for reconstructing spring temperatures back to the eighteenth century.
abstract: Following an age-old tradition, since 1740, in the town of Kőszeg in western Hungary, samples of grapevine shoots are annually harvested on St. George's Day, 24 April, and then are pictorially reproduced in the so-called Book of Vinesprouts. Given the strong relationships between temperature and grapevine phenology, the book represents a potential source for reconstructing past spring temperatures. However, this document has been little utilized so far, due to high varietal heterogeneity and lingering uncertainty regarding cultivar identity. This research developed an approach to address these difficulties, by means of a single-cultivar-based modeling analysis, associated with a set of alternative hypotheses about cultivar early development for the period to be reconstructed. Each hypothesis allowed the calculation of a different past temperature reconstruction, which was evaluated against contemporary independent observational data. The results showed that all the development stages recorded before 1900 were compatible with a vine type with a very low heat requirement for bud burst. Estimates were derived from a model calibrated on a subset of drawings of unknown cultivars executed between 1875 and 1898. The model based on this data subset was the only one giving a consistent reconstruction of spring temperatures, expressed as accumulated growing degree days going back to 1740. Although some uncertainty still exists regarding the reconstruction, the research shows that the Book of Vinesprouts contains generally consistent information about spring temperatures for a period of over 269 years for this region of Hungary.
authors.affiliation: Consiglio per la ricerca in agricoltura e l'analisi dell'economia agraria (CRA) - Centro di ricerca per le colture industriali, Via di Corticella 133, Bologna, I-40128, Italy. gianni.fila@entecra.it.
authors.forename: Gianni
authors.initials: G
authors.lastname: Fila
authors.affiliation: Consiglio per la ricerca in agricoltura e l'analisi dell'economia agraria (CRA) - Centro di ricerca per la viticoltura, Viale XXVIII aprile 26, Conegliano, I-31015, Italy.
authors.forename: Diego
authors.initials: D
authors.lastname: Tomasi
authors.affiliation: Consiglio per la ricerca in agricoltura e l'analisi dell'economia agraria (CRA) - Centro di ricerca per la viticoltura, Viale XXVIII aprile 26, Conegliano, I-31015, Italy.
authors.forename: Federica
authors.initials: F
authors.lastname: Gaiotti
authors.affiliation: Department of Environmental Studies, Southern Oregon University, 101A Taylor Hall, Ashland, OR, 97520, USA.
authors.forename: Gregory V
authors.initials: GV
authors.lastname: Jones
mesh_terms: D001878:Books, Illustrated; D057231:Climate Change / Q000266:history*; D049671:History, 18th Century; D049672:History, 19th Century; D049673:History, 20th Century; D049674:History, 21st Century; D006814:Hungary; D008962:Models, Theoretical; D018515:Plant Leaves / Q000254:growth & development; D018520:Plant Shoots / Q000254:growth & development; D012621:Seasons; D013696:Temperature; D027843:Vitis / Q000254:growth & development*
keywords: Climate change; Grapevine; Hungary; Phenology; Spring temperatures