HYDROGEN CYANAMIDE ADVANCES PECAN BUDBREAK AND HARVESTING

Dormant season sprays of hydrogen cyanamide applied to pecan [Carya il linoinensis (Wangenh.) K. Koch] trees advanced budbreak, flowering and shuck dehiscence. Hydrogen cyanamide was applied to dormant branches at approximate to 60, 45, 30, and 15 days before normal vegetative bud break at rates of 0, 120, 240, 480, and 960 mM (corresponding to appro ximate to 0%, 0.5%, 1%, 2%, and 4%, solutions for 3 years). Depending on treatment, hydrogen cyanamide advanced budbreak by as much as 17 da ys, female and male flower maturity by up to 15 days, and nut ripening by as much as 14 days without reducing nut yield or causing phytotoxi city. Hydrogen cyanamide applied at 480 to 960 mM approximate to 60 da ys before expected budbreak possibly may be used commercially to advan ce ripening, manipulate time of pollen dispersal, and substitute for c hilling when pecan is grown in mild environments.