Effect of grafting on the growth and flowering of sprays chrysanthemums

To study the effect of grafting on the growth and flowering of spray chrysanthemum, Artemisia annua was used as the rootstock and eight spray chrysanthemum varieties 'Zhongshan Jinyang' ('ZSJY'), 'Zhongshan Xinmolian' ('ZSXML'), 'Zhongshan Xuerong' ('ZSXR'), 'Zhongshan Yinggui' ('ZSYG'), 'Zhongshan Zaohong' ('ZSZH'), 'Zhongshan Zhiying' ('ZSZY'), 'Zhongshan Zisongguo' ('ZSZSG'), and 'Zhongshan Ziwei' ('ZSZW') were used as the scions. The plant survival ratio, growth index (crown width, crown circumference, and biomass), and flowering characteristics (total inflorescences per plant, flower diameter, fresh and dry weight of single flowers, and flowering period) were studied after grafting. We found that for variety 'ZSYG', the grafted plants showed a 58.4% increase in crown width, a 68.7% increase in crown circumference, a 61.8% increase in the dry weight of the scion, a 108.4% increase in the dry weight of root, a 72.3% increase in the total dry weight, a 28.3% increase in root/shoot, and a 135.2% increase in the total inflorescences per plant compared to those in the own-rooted plants. Grafting can not only promote plant growth and increase plant biomass, and the total inflorescences per plant of spray chrysanthemum but also lengthen the ornamental period of spray chrysanthemum by advancing flowering and delaying the final flowering period. The budding period can be advanced by 13 d, the final flowering period can be delayed by 4 d, and the ornamental period can be increased by 10 d. Therefore, grafting facilitates the growth of spray chrysanthemums, advances flowering, and prolongs the ornamental period.