Table 2.

Climate variables used for investigating grape fruit quality attributes at maturity

Climate variable	Climate variables used previously	Additional variables used for this study
Temperature	Mean January temperature (Smart and Dry 1980; Webb et al. 2008a); Spring temperatures up to flowering (Keller et al. 2010)	October–February monthly minimum, maximum, and average temperatures (°C)
	Growing season (GS) a average temperature (Ashenfelter 2008; Jones et al. 2005)	GS minimum, average, and maximum temperatures
	Temperature during fruit maturity (Sadras et al. 2007a; Storchmann 2005)	Minimum, maximum, and average temperatures during ripening periodb (RP); Number of hours over 25 °C during RP
	Degree days (sum of daily mean temperature over 10 °C during GS) (Winkler 1974)	Growing degree days (GDD) during GS
	Number of days with maximum temperature over 25 °C during GS (Jones and Davis 2000)	Number of days with maximum temperature over 25 °C during GS, and RP
	Diurnal range (DR) (Gladstones 1992; Nemani et al. 2001)	Monthly DR between December and February, GS, RP, veraison to maturity period c, and for the period between October and February
Moisture condition	Rainfall (mm) (Gladstones 1992)	Amount of rainfall for early (September–November) and for the whole GS
	Moisture stress (Chalmers et al. 2010; Gladstones 1992)	Daily mean evaporation between October and February months, and RP; mean daily vapour pressure deficit (VPD) for October–February, and for RP
	Soil water holding capacity (Jackson 2000; Sivilotti et al. 2005)	Available soil water holding capacity in the top 2 A and B soil layers
Radiation	Radiation (Ristic et al. 2007; Gladstones 1992)	Mean daily radiation between October and February, and for RP

^aGrowing season: period between October and the date when the grapes reached 22°Brix total soluble solids (TSS), i.e. common maturity

^bRipening period: 30 days period preceding common maturity

^cThe veraison to maturity period: period between the start of veraison and common maturity