Effects of plant growth retardants on the growth of shoot and production of flower of Lonicera japonica Thumb

In order to investigate whether the yield and quality of flower Chinese medicine can be improved by control the growth of shoot, three kinds of plant growth retardants, Cycocel (CCC), Mepiquat chloride (Pix) and Uniconazole (S-3307) with different concentrations were used by spraying on Lonicera japonica Thumb just before the anthesis and at the beginning of flowering. The results show if the concentrations are appropriate, these retardants would restrain the growth of shoot obviously and not affect the growth of flower of Lonicera japonica, and even would increase the yield by improving the flower bud differentiation and then the quantity of flowers. Pix with the concentrations of 100 and 200 mg/L have the best effects on the yield, with the highest increase ratio above 45%. S-3307 with the concentrations of 150~200 mg/L has good effects as well. The contents of flavonoids and chlorogenic acid in flowers treated with different concentrations of Pix are increased, with the highest increase of the total flavonoids is about 27.5%, and the chlorogenic acid is about 14.3%. However, the other two retardants have not any significant improving effects. Overall, the Pix with the concentration of 100~150mg/L has the best effects on improving the yield and quality of honeysuckle flowers. Therefore, it is feasible to improve the yield and quality of flowers by controlling the growth of shoots in Lonicera japonica.