Variation in Amounts of Epicuticular Wax on Leaves of Prosopis glandulosa

Abstract

Epicuticular wax weight, leaf dry weight, and area of honey mesquite (Prosopis glandulosa Torr.) leaves were determined periodically during a growing season at six locations in Texas with contrasting climates. Leaf size and wax weight per unit leaf weight and leaf area of individual trees within each population did not differ significantly on any sampling date. Significant variation was observed among population means, both within and across sampling dates, but the population means did not vary by as much as a factor of two. Amounts of epicuticular wax per unit leaf area were least in April and May, increased until July, and remained stable thereafter at most locations. Population means ranged from ca. 4 mg dm-2 in east-central Texas during April and May to a maximum of over 10 mg dm-2 on leaves of trees growing in north-central Texas in October. Honey mesquites growing in arid west Texas and semiarid south Texas had no more wax per unit leaf weight or area than those in humid east-central Texas.