Abstract: Zinnia elegans is widely used in landscaping. Confronting potassium (K) resource shortage in China, it is necessary to clarify the optimum amount of potassium application and improve potassium utilization efficiency. This paper studied the effects of different potassium application treatments (0 mg/kg, 100 mg/kg, 200 mg/kg, 300 mg/kg and 400 mg/kg) on growth and bloom of Zinnia elegans by pot experiments, so as to provide theoretical basis for the rational application of potassium fertilizer in the cultivation process of Zinnia elegans. The results indicated that potassium application was beneficial for increasing plant height, leaf number, shoot dry weight, root dry weight, number of flowers and flower diameter. All these indexes showed a tendency of increasing first and then decreasing with the potassium level rising. When the potassium level was 300 mg/kg, these indexes reached the highest level, then declined at 400 mg/kg, but still higher than those of the control. Under this experiment condition, 300 mg/kg was the most appropriate potassium level to Zinnia elegans for its growth and bloom.

Key words: Zinnia elegans, potassium, growth, bloom

摘要： 百日草广泛应用于园林绿化，面对我国钾素资源短缺的问题，必需明确百日草的最佳施钾量，提高钾素利用效率。通过盆栽试验研究不同供钾处理(0 mg/kg、100 mg/kg、200 mg/kg、300 mg/kg和400 mg/kg)对百日草生长和开花的影响。结果表明：施钾有利于提高百日草的株高、叶片数、地上干重、根干重，开花数和花直径，这些指标均随施钾水平的升高呈现先上升后下降的变化趋势，且均为钾处理300 mg/kg时最高，400 mg/kg钾处理时指标有所降低，但仍高于对照。该试验条件下，300 mg/kg钾处理的百日草生长和开花最好，是百日草的最适施钾水平，该结果为百日草栽培过程中钾肥的合理施用提供理论依据。

关键词: 百日草, 钾, 生长, 开花