Abstract
Ethephon alone and in a mixture with inorganic defoliants was used to defoliate apple nursery trees of three cultivars: Yellow Transparent, McIntosh and Jonathan. The mixture of ethephon with copper sulphate or magnesium chlorate defoliated the trees better than ethophon or inorganic defoliants used seperately in twice as high concentrations as in a mixture. The tress defoliated with the mixtures of defoliants suffered less from frost injury than those treated with only the inorganic defoliants.