Growth, Fruiting, Flowering, and Fruit Quality of Sweet Cherries Treated with Paclobutrazol

Abstract

Five-year-old `Napoleon' sweet cherry (Prunus avium L.) trees were treated with single-application basal drenches of paclobutrazol (PBZ) in an attempt to regulate growth and flowering. Increasing concentrations of PBZ at 0.05 to 0.30 g·cm-1 trunk diameter reduced terminal extension the year of treatment and for at least the following 3 years. Fruit count increased on wood grown before treatment but decreased as annual growth declined following treatment. Fruit/cm growth generally increased, whereas fruit per flower bud decreased as PBZ concentration increased. No differences were found in fruit size, soluble solids concentration (SSC; 13% to 14%), or firmness of cherries harvested at brine maturity. Chemical name used: β-[(4-chlorophenyl) methyll-α- (l,l-dimethylethyl) -l-H-l,2,4-triazo1e-l-ethanol (paclobutrazol, PBZ).