Abstract:

【Objective】 The aim of this study was to reduce the production cost and improve the utilization rate of water and fertilizer, and to realize the precise control of potted flowers. 【Method】 The law of absorption and utilization of water and nutrition in different developmental stages of poinsettia was studied by equation regression. 【Result】 It was found that the change curves of water and nutrition uptake as well as the change curves of biomass accumulation in poinsettia showed S pattern. The determination coefficient of the models established by logistic regression equation y=1/(a+be-x) was higher than 0.99. The rate of biomass accumulation, as well as water production and nutrition absorption in poinsettia was right deviation bell-shaped.【Conclusion】The suitable watering frequency and fertilizer amount matching specified medium in different developmental stages of poinsettia were simulated. Watering when the medium water content was 65.09% during 31-53 days, 66.83% during 54-93 days, and 64.34% after 93th day, the water amount was 500.00 mL per pot. The fertilizer amount was 794.68-808.59 mg per pot during 31-58 days, 827.15-833.33 mg per pot during 59-107 days, 831.01-833.33 mg per pot after 107 days, once a week. These conclusions provided a technical support for low cost, high quality and efficient production of potted poinsettia with precise control of water and nutrition.

Key words: Euphorbia pulcherrima, water, nutrition, absorption and utilization, precise control