A propagation technique for rooting adult phase pecan, Carya Illinoensis (Wang) K. Koch, stem cuttings

Abstract

This study attempted to develop a technique for propagating adult phase cuttings as clonal rootstocks that could be used to produce trees capable of uniform growth and ion absorption. Both hardwood and semi-hardwood adult phase pecan cuttings were rooted. Juvenile cuttings were used as a control. Experiments were conducted to determine the effects of ethephon, indolebutyric acid (IBA), and potassium salt of indolebutyric acid (KIBA). Ethephon did not significantly promote rooting more effectively than IBA or KIBA. However, ethephon treatments of 1,250 ppm and 2,500 ppm produced root systems with more lateral branching than KIBA or IBA at 10,000 ppm. These ethephon-treated cuttings would probably survive better than the auxin treated cuttings because of a larger root absorption surface. Results indicated that quick basal dips of 10,000 ppm IBA and KIBA should remain the standard practice in rooting pecan stem cuttings. No phototoxic symptoms were observed using 95% ethanol as the solvent for IBA (10,000 ppm) versus water as the solvent for KIBA (10,000 ppm). There had been earlier speculation that ethanol might be phototoxic. Since the KIBA- water solution gave no better response than the IBA-ethanol solution, and since ethanol seemed to increase auxin uptake, it would appear that the more stable IBA-ethanol solutions should be used in future research in preference to the less stable KIBA-water solutions..