Study of the variability of cork growth in northern Algeria

Abstract

The study of the growth of Algerian cork according to the concept of origin was carried out on 100 samples of 20x20cm representing ten production regions (El Tarf, Jijel, Skikda, Mila, Guelma, Bejaia, TiziOuzou, M'Sila, Hafir, Zarieffet). The caliber varies significantly from one to another (Origin 1). On average, it was about 29.75 mm with a still regressive aspect in the Western Region (Origin 2) and the Mountain Zone (Origin 3). The mean annual increments for an 8 year production cycle follow the same path, very significantly different between the samples of the Eastern Region (3,14mm year^-1: El Tarf, Jijel, Skikda Guelma and Mila), the Central Region (3.19 mm year^-1: Tizi Ouzou and Bejaia) and Western Region (2.64 mm year^-1: M'Sila, Zarieffet and Hafir), a reduction of 12% in the Mountain Area. Growth indices were very stable for samples of origin1, shades and growth irregularities appear by applying the concept of origins 2 and 3. Regardless of the origin used, the indices of growth rate are type fast in Central and Eastern Region and middle type in the Western Region. This fact also applies to the Coastal Zone more than the Mountain Area.