EFFECT OF TRIACONTANOL AND CHLORMEQUAT ON GROWTH, PLANT HORMONES AND ARTEMISININ YIELD IN ARTEMISIA-ANNUA L

Artemisinin and herbage yield of Artemisia annua plants were determined after application of triacontanol (tria.) and chlormequat (2-chloroethyltrimethylammonium chloride). Tria. at 1.0 and 1.5 mgl-1 produced a statistically significant positive effect on artemisinin level as well as on plant height, leaf and herbage yield. Chlormequat at 1000 and 1500 mgl-1 also increased artemisinin level, decreased the plant height at higher concentrations and increased the leaf and herbage yield at lower concentrations. Tria. application enhanced GA-like activity, but ABA levels decreased, while chlormequat increased ABA but reduced GA-like substances. The effect of Tria. on artemisinin yield seems to be mediated through its effect on plant growth.