BerryTone—A simulation model for the daily course of grape berry temperature
, Osvaldo Failla, Luigi Mariani
degli Studi di Milano, Department of Crop Science, Italy
Physiological and phenological behaviour of grapevine (Vitis
vinifera L.) is strongly inﬂuenced by meteorological variables
which are very important for the ﬁnal quantity and quality of the
grapes. Taking into account the classical subdivision in spatial-
temporal scales (Bluestein, 1992; Stull, 1997), the relevance of
single meteorological variables for quantity and quality of
vineyard production can be analysed at macroscale (Jones and
Davis, 2000), mesoscale (Chevet and Soyer, 2006) and microscale
(Larcher, 1995; Haselgrove et al., 2000).
Thermal behaviour of sink organs (grape berries) is a crucial
driving variable for the bulk of biochemical and physiological
phenomena involved in the ripening and it is a key factor for
qualitative proﬁling in terms of primary and secondary metabo-
lites (Jackson and Lombard, 1993).
The physiological bases of the relationships between grape
temperature and metabolism are far from being completely
understood. Nevertheless many efforts have been devoted to
deﬁne the most appropriate fruit thermal status to reach the best
grape quality, according to each wine style (Mariani et al., 2007).
Several studies have discussed the link between temperature
and (i) sugar accumulation (Coombe, 1987), (ii) anthocyanins
accumulation (Bergqvist et al., 2001; Dokoozlian and Kliewer,
1996; Downey et al., 2003; Haselgrove et al., 2000; Mori et al.,
2005; Spayd et al., 2002), (iii) ﬂavonols accumulation (Downey
et al., 2004; Spayd et al., 2002), (iv) tannins synthesis (Downey
et al., 2004), (v) terpen synthesis (Macaulay and Morris, 1993) and
(vi) carotenoids and methoxipyrazines synthesis (Hashizume and
So far, these processes have been studied by taking into
account air temperature. Yet, using cluster related data instead,
the knowledge of these phenomena could be improved. The ﬁrst
way is to measure the cluster temperature directly (Millar, 1972;
Bergqvist et al., 2001; Spayd et al., 2002; Tomasi et al., 2003), but
this method is not widespread because of the high costs and
complicated management of the equipment. Facing these
problems, a proﬁtable approach is given by simulation with
physical frameworks founded models. Energy balance is a
micrometeorological technique (Munn, 1966; Oke, 1978; Stull,
1997; Burba et al., 1999) used to simulate thermal behaviour of
living bodies. Such technique produces datasets directly referred
to the canopy layer and therefore directly linked to the
ecophysiological aspects of ripening. These models have long
been used to analyze the thermal behaviour of systems and are
grape berries. Some examples of this kind of approach may be
found in literature. For example, an energy budget approach was
adopted by Patin
o et al. (1994) to simulate temperature of fruits
Agricultural and Forest Meteorology 149 (2009) 1215–1228
Received 14 March 2008
Received in revised form 17 December 2008
Accepted 20 January 2009
Grape temperature is a crucial driving variable for the wide variety of biochemical and physiological
processes taking place during berry ripening which determine the oenological quality potential of
grapes. The aim of this work is to develop, calibrate and validate a model simulating surface berry
temperature (BerryTone), taking into account the effect of different sun exposures and leaf shadings.
BerryTone has been developed using a mechanistic approach founded on the energy balance and it is
driven only by maximum and minimum daily air temperatures. Calibration and validation have been
carried out on independent dataset in Northern Italy during 2005 and 2006. In order to evaluate the
effectiveness of the model in other environmental conditions, a further test on a time series from 2008 in
Central Italy was also carried out. Final results show that the model satisfactorily described berry
thermal behaviour under solar forcing for different exposures, improving upon the description usually
given by air temperature.
ß 2009 Elsevier B.V. All rights reserved.
* Corresponding author at: Universita
degli Studi di Milano, Dipartimento di
Produzione Vegetale, Via Celoria, 2 - 20133, Milano (MI), Italy.
Tel.: +39 0250316587; fax: +39 0250316575.
E-mail address: email@example.com (G. Cola).
Contents lists available at ScienceDirect
Agricultural and Forest Meteorology
journal homepage: www.elsevier.com/locate/agrformet
0168-1923/$ – see front matter ß 2009 Elsevier B.V. All rights reserved.