Provenance Variation in Pecan

Abstract

An assessment of vegetative traits of pecan [Carya illinoinensis (Wangenh.) K. Koch] from a range-wide provenance collection indicated the existence of at least two distinct populations within the native range (i.e., provenances north of Texas vs. provenances in Texas and Mexico). Southern most provenances generally broke bud earlier, retained foliage later in the fall, grew larger in height and trunk diameter, had narrower leaflet droop angles, had greater leaflet tilt angles, wider limb angles, greater Zn deficiency, less black pecan aphid susceptibility, and less red coloration to foliage than did northern most provenances. Trees originating from Jaumaua, in northern Mexico, were especially noteworthy insomuch that they were by far the tallest, possessed the largest trunk diameters, the longest foliation period, and lowest Zn deficiency ratings of all provenances. One family within this Jaumaua population also exhibited a high level of cold hardiness. Family heritability (hf2) estimates were ≥0.48 for trunk cross sectional area, date of budbreak, leaf redness, cold injury, leaflet droop angle, and leaflet tilt angle, and ≤0.39 for late season leaf fall, black pecan aphid susceptibility, zinc deficiency, and branch angle.