Differences of raw cork quality in productive cork oak woods in Sicily in relation to stand density

How resilient is Quercus suber L. to cork harvesting? A review and identification of knowledge gaps

“…Unfortunately, reports on the effects of cork stripping intensity on the radial growth of Q. suber are scarce. Recently, Pizzurro et al (2010) reported negative and significant correlations between cork thickness and cork harvesting parameters namely cork harvesting coefficient, harvested surface and maximum harvesting height, in two cork oak stands in Sicily (Italy), confirming the empirical assumption of a negative impact of cork harvesting on cork production (Montoya-Oliver, 1985;Natividade, 1950). In contrast, Garchi and Sghaier (2008) found no significant correlation between the harvesting coefficient and cork thickness in Tunisian cork oak stands, in agreement with results obtained by Fialho et al (2001) in young trees harvested for the first time.…”

Characterization of Sardinian cork oak (Quercus suber L.) genetic resources for economically important traits

“…Corona et al (2005) state that cork quality variability is high even under identical site conditions, and identification of which factors best characterise a site in term of quality is controversial. Image analysis techniques were used by Pizzurro and Maetzke (2009) to measure cork rings, and dendrochronological analysis was applied to study annual fluctuation on rings growth in relation to various climate characters in a cork cycle production in Sicily. Their results showed that rainfall, summer drought and air temperature are determining factors in controlling cork growth.…”

“…According to Corona et al (2005), the production of cork stoppers is the most remunerative industrial product of cork oak in Sardinia and requires a raw material with elevated elasticity to assure good bottle closure, and with limited presence of lenticels, especially if they have a large diameter (Pereira et al 1996;Vieira Neto 1996). The quality of raw cork is controlled by the interaction of genetic and environmental factors (Nativitade 1934;Dettori et al 2001;Pizzurro et al 2010).…”

“…According to several authors, environment influences cork quality (Isasa 1959;Ahmed 1994;Dettori et al 1996;Courtois and Masson 1999;Pizzurro and Maetzke 2009) and the conditions favouring an intense vegetative activity may cause an increase in the diameter of lenticels and a decrease in the commercial value of cork (Natividade 1950).…”

The cork viewed from the inside

“…Generally there are 7 or 8 qualities (Ferreira et al, 2000;Benkirane et al, 2001;Fédération française des syndicats du liège, 2006;Natural cork users group, 2007), but there is no well-defined standard (Pizzurro et al, 2010). Class 0 represents the best quality while 6 or 7 (depending on the classification used) is the poorest.…”