SOME EFFECTS OF CHLOROCHOLINE CHLORIDE ON MENTHA PIPERITA

Abstract

The plant growth régulant chlorocholine chloride (CCC), in concentrations ranging from 50 to 16,000 ppm was applied as a soil drench to young Black Peppermint (Mentha piperita) plants. Treatment effects (i. e. reductions in height and leaf size, enhancement of leaf colour (and with 16,000 ppm) toxicity symptoms) were evident within one week .Growth analyses throughout the vegetative period indicated that treated plants eventually grew out of the retardation caused by CCC. At harvest, most treated plants, compared with controls, were shorter and their fresh weight and moisture content greater. Their dry weight was reduced by CCC concentrations above 1000 ppm. The percentage volatile oil content (based on fresh weight) was decreased by all treatments, but based on dry weight, only by 16,000 ppm. GLC analysis of oil monoterpenes indicated reductions in hydrocarbons and menthol, but increases in menthone and menthyl acetate after CCC treatments. Although increasing concentrations of chemical caused progressively more pronounced effects the results indicated two possible levels of activity, low (< 500 ppm) and high (> 500 ppm).