THE EFFECT OF DIFFERENT HARVEST DATES ON THE YIELD AND QUALITY OF THE GOLDEN THISTLE (Scolymus hispanicus L.)

Abstract

The objective of this study was to determine the yield and quality characteristics of golden thistle (Scolymus hispanicus L.) harvested at different maturity stages. The trial was arranged in the Randomised Complete Block Design under the ecological conditions of Izmir, Turkey in 2017 and 2018 growing seasons and the plants were harvested from November to August at 10 monthly periods. Root lenght (cm), root yield (kg ha-1 ), root bark yield (kg ha-1 ), dry root bark yield (kg ha-1 ), root collar diameter (mm), root xylem diameter (mm), cortex thickness (mm), taraxasterol rate (%) taraxasterol acetate rate (%) were determined. The highest root and root cortex yields were obtained from the plants harvested in july, the average of two years as 19770.64 kg ha-1 and 6480.65 kg ha-1 , respectively. The highest taraxasterol and taraxasterol acetate rates were obtained in May harvest as 0.042% and 0.015% in two years respectively.