Abstract
The defoliants used on shrubs in the nursery were: ethephon, KJ, Mg(ClO3)2•6H2O, CuSO4•5H2O, (NH4)2SO4 in various concentrations separately or as mixtures. Spraying was performed on September 26-28 1972 and 1973. The most effective defoliant for Rosa cv. Lampion, Spiraea X bumalda cv. Froebelii, Spiraea X vanhouttei shrubs was KJ applied at a concentration of 0.2% or used in mixture with ethephon or (NH4)2SO4 in lesser concentrations. Effective defoliation of many shrubs including Forsythia X intermedia was obtained with Mg(ClO3)2 used at a concentration of 0.24-0.48% or CuSO4 at concentration of 2%. But at the same time these defoliants brought about comparatively the greatest retardation in shrubs development and growth and, in the case of Forsythia X intermedia, reducted also frost resistance.