Study on the Hydroponic Cutting Technique of Hydrangea macrophylla ‘Endless Summer’

Taking Hydrangea macrophylla ‘Endless Summer’ as the research object, the effects of different types of hydroponics equipment, different types and concentrations of rooting agents on cutting rooting of Hydrangea macrophylla ‘Endless Summer’ were studied under static hydroponics conditions. Through the comparative analysis of growth indicators, the best hydroponic cutting rooting scheme was summarized, providing reference basis and technical support for the subsequent factory seedlings of Hydrangea macrophylla ‘Endless Summer’ and hydroponic cutting of other Hydrangea varieties. The effects of different types of hydroponic equipment, rooting agents and concentrations of rooting agents on the earliest rooting time, average rooting rate, average root length and average root quantity of Hydrangea macrophylla ‘Endless Summer’ hydroponic cuttings after rooting were studied by using a four-factor and three-level experimental design. In the treatment 9, the cuttings were soaked with 200 mg·L⁻¹ ABT rooting agent for 5 min and then cultured in the "A type" structure of the aerosol culture mode, the growth of the cuttings was the best. In the treatment 8, the cuttings were soaked with 200 mg·L⁻¹ NAA rooting agent for 5 min and then cultured on the DFT deep-flow culture vegetable wall, the rooting effect was the worst. In the treatment 4, the cuttings were soaked with 200 mg·L⁻¹ IBA rooting agent for 5 min and then cultured in the NFT single-layer flat structure, the root germination time was the earliest. In the treatment 3, the cuttings were soaked in 300 mg·L⁻¹ NAA rooting agent for 5 min, and then cultured in NFT mode single-layer flat structure, the rooting was the latest. The types of rooting agents were the most important factor affecting the earliest rooting time and root quantity in hydrangea hydroponics cutting results, and the type of hydroponics equipment was the most important factor affecting the average rooting rate and root length growth, among which the "A type" structure of the aerosol culture mode was the best for cutting and rooting. Among different rooting agents, IBA was the most beneficial to the early rooting time, but ABT was the most beneficial to the growth of cuttings, and low concentration of NAA was the most beneficial to the increase of root mass. The concentration of rooting agent did not affect the rooting rate of Hydrangea macrophylla 'Endless Summer' hydroponic cutting.