# Early Basal Leaf Removal at Different Sides of the Canopy Improves the Quality of Aglianico Wine
###### Abstract  
It is well known that the early removal of basal leaves is a viticultural practice adopted to improve the exposure of clusters to direct sunlight and UV radiation and increase the phenolic compounds and anthocyanin concentration in the berries. The aim of this work was to study the influence of early basal leaf removal on Aglianico wines produced in the Apulia region (southern Italy) during three consecutive seasons. Three vine treatments were carried out, where 100% of the cluster-zone leaves on the north, south and both sides of the canopy were removed. Undefoliated plants were used as a control. The effect of the treatments on the basic chemical parameters, phenol content and volatile composition of wines was investigated using WineScan FT-MIR, spectrophotometry, HPLC-DAD and SPME-GC/MS. Early defoliation increased the amounts of flavonoids (+35-40%), anthocyanins (+15-18%), total polyphenols (+10%), antioxidant activity (+8-14%) and colour intensity (+10%), especially when leaf removal was applied on the south side. Moreover, leaf removal led to a 40% increase in free anthocyanins when applied on the south side of the canopy, while a 24% increase was observed when applied to the north side and 21% when applied to the north and south sides. A negative effect was observed on volatile compounds, which decreased by about 18, 14 and 13% when the treatment was applied on the north, north-south and south sides of the canopy, respectively. In conclusion, early leaf removal treatments allow for the modulation of the phenolic and volatile concentrations of Aglianico wines. vine defoliation; color intensity; polyphenols; antioxidant activity; anthocyanin profile; volatile profile +
Footnote †: journal: _Foods_  
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Among vicultural practices, early basal defoliation is frequently applied to reduce the incidence of bunch rot and enhance the quality of the grapes and wine by modulating the microclimate around the bunch [11; 12; 13]. Early defoliation affects the concentration of soluble solids, phenols and anthocyanins in grapes [11; 12] and wines [14]. Its positive effects on grape and wine composition are related to the modification of canopy porosity, leaf/fruit ratio, cluster and berry exposure and skin/berry ratio [14; 15]. In a three-year study on defoliation applied to cv Barbera in northwest Italy, it was found that when the climatic conditions were less favorable for grape ripening, the quality of the must and wine increased, whereas no effect was observed in warmer years [16]. [PERSON] et al. [17] reported that defoliation applied to varieties characterized by different anthocyanin and flavonoid profiles (Cabernet Sauvignon, Nero d'Avola, Raboso Piave and Sangiovese) showed a genotype-dependent response [17]. Recently, several studies were performed to assess the impact of basal leaf removal on volatile organic compounds in grapes and wine with controversial results. The existing discrepancies among these studies indicate that the grape variety or clone [18; 19], climate conditions [20], grape maturity [21] and the timing and severity of leaf removal [20; 22; 23] may be responsible for the observed effects of basal defoliation on the aromatic properties of grapes and wine. Aglianico is a late-season red wine grape variety grown in the Apulia, Campania and Basilicata regions in southern Italy, which are characterized by a warm and arid climate. For this variety grown in the geographical area of Potenza (Basilicata), anthocyanin compounds were shown to be increased due to the late defoliation at veraison with or without 40% cluster thinning [24]. In another study on Aglianico (Castel Campagnano, Campania), a reduction in grape sugars and alcohol in wine was observed as a result of two different defoliation intensities performed near harvest time [25]. In contrast, [PERSON] et al.