Pecan Production Responds to Root Carbohydrates and Rootstock

Abstract

Abstract The problematic alternate-bearing characteristic of pecan [ Carya illinoensis (Wangenh.) C. Koch] has prompted an investigation of the role of rootstock and carbohydrate concentrations in tree organs in relation to nut production. Six years of data on the influence of open-pollinated pecan rootstocks on in-shell nut production by 80- year-old trees of ‘Stuart’ of ‘Schley’ scion cultivars provide evidence that rootstocks may influence yield, yield efficiency, and alternate bearing and that yield is closely associated with January root starch concentrations. Several “superior” trees, possessing greater-than-average nut yields and less-than-average alternate-bearing intensity, were identified as candidates for improved pecan rootstocks, indicating a projected frequency of ≈5% for the occurrence of superior rootstocks.