Variation in amounts of epicuticular wax on leaves of Argania spinosa (L). Skeels

Epicuticular wax and leaf dry weights, leaf area, amounts of epicuticular wax per unit leaf weight or area and specific leaf dry weight from 65 trees of Argania spinosa were determined, during July 2001 and 2002 (dry seasons) and January 2002 (wet season), at five sites in South West Morocco, with contrasting climates. Significant variations were found both within and across sampling sites and dates for all parameters. Results showed lowest amounts of epicuticular wax per unit area in January than in July, for all sites. Population means in January ranged from ca. 12.80 mg.dm(-2) to over 16.39 mg dm(-2). In July, amounts ranged from 14.15 mg dm(-2) to 17.11 mg dm(-2). However, no diffrences were observed in the quantity of wax per unit leaf weight or area between trees although their different climates. All the studied characters were significantly correlated between them, except leaf dry weight with wax weight by leaf dry weight. The response's variation among trees in epicuticular wax and the correlation between wax amounts and the other studied characters as specific leaf dry weight suggest the possibility of selection process of drought tolerant genotype.