031 EFFECT OF BLANCHING, IBA CONCENTRATION, AND PLANT GROWTH REGULATORS ON GROWTH AND OVERWINTER SURVIVAL OF CUTTING-PROPAGATED ORNAMENTALS

Abstract

Budbreak inhibition and poor overwinter survival (OS) limit successful cutting propagation of Acer rubrum October Glory, A. rubrum Red Sunset, Hamamelis vernalis, H. virginiana and Stewartia pseudocamellia. Localized blanching (banding) of the cutting on the stock plant; a range of 3 IBA concentrations, and foliar spray application of: 1% silver thiosulfate(STS), STS followed ten days later by Gibberellin, GA4/7:250ppm(STS GA),50ppm thidiazuron (TDZ) and TDZ followed by GA4/7 (TDZ GA)were tested for increasing growth and overwinter survival.. Carbohydrates were analyzed in cuttings which did and didn't grow. A. rubrum October Glory*, and Hamamelis spp all had increased OS for cuttings which grew. A. rubrum Red Sunset demonstrated a similar trend. Hamamelis spp. had significant increase in carbohydrates for cuttings which grew. A. rubrum October Glory' exhibited the same trend. S. pseudocamellia did not have increased OS with growth. and showed no increases in carbohydrates with growth, but the cuttings that didn't grow had at least 93 % more carbohydrates than the other species analyzed. All species had higher OS when stored in the 3° C cooler, than in the fluctuating cold frame. Banding increased growth of A. rubrum October Glory, and H. virginiana. IBA concentration affected growth of all species. STS increased growth of H. virginiana and S. pseudocamellia. GA4/7 increased growth of all cuttings except A. rubrum October Glory.