2018 ASHS Annual Conference

One of the most important characteristics of ornamental potted plants is their proper compact growth habit. The most common way to achieve compactness during plant production is usage of chemical growth retardants. However, some of these chemicals have a hazardous character and have been prohibited in a range of European countries due to their toxicity to humans and negative impact on environment.

In our studies we investigated the influence of ethanol treatment on a growth habit of a popular ornamental potted plant Euphorbia pulcherrima cv. Premium Ice Christal. During vegetative growth the plants were watered with ethanol solution in concentrations: 0, 0.5, 1, 2, 4 or 8%. All concentrations of ethanol, except 0.5%, resulted in more compact growth than control plants, however, the concentrations of 4% or 8% caused chlorotic and necrotic spots, or in some cases even death of the plant. Fresh and dry weight, and plant diameter decreased when concentration of ethanol increased. No delay in coloration of bracts was observed.

Ethanol treatment used in appropriate concentrations appears to be an excellent alternative to chemical growth retardants for induction of compact growth. Ethanol is inexpensive, biodegradable material, non-toxic in proper concentrations, which can easily be integrated into a commercial production.