Effect of Brushing on Dwarfing, Branching and Flowering of Dendromthema indicum var. hortense

Dendranthema indicum var. hortense plants were brushed gently with a soft plastic dusting brush 15 times (back and forth) per day for 7, 14, or 21 days, or brushed 10, 20, or 30 times per day for 15 days. Twenty-six days after treatment ended, plant heights were reduced significantly by all treatments. As time elapsed after brushing treatments, the dwarfing effect was decreased but the effect persisted after 21-day treatment with both suppression of both branch length and leaf area. Branching increased in the plants treated 30 times for 14 days and 15 times for 21 days. Both the fresh weight and dry weight of the shoot and root were also reduced. However, the chlorophyll content was not affected 80 days after planting. Stomatal width was deceased in plants treated 15 times for 21 days, but stomatal length was not affected by brushing. Number of stomata was increased greatly in plants treated 15 times for 21 days compared to the control. Days to emergence of flower buds were shortened by 6 days in plants treated 15 times for 21 days. The number of flowers increased in the plants treated 30 times for 14 days and 15 times for 21 days. Bases on this experiment, it is recommended to brush plants 15 times per day for 3 weeks to promote Dendranthema pot production with high quality.