The Effect of Seaweed Extract and LED on the Growth and flowering of Two Lisianthus Cultivars

Lisianthus is a slow-growing flowering plant whose seed germination and growth is a challenge in the tropics. Due to the marketability of this type of cut flower, this study was performed in two experiments to investigate the effect of seaweed extract (SWE) and LED on the growth of seedlings of two cultivars of lisianthus (namely Ariana and Mariachi) and its effect on flowering as a factorial experiment in a completely randomized design. The first experiment consisted of LED treatments with blue, red, blue-red, and white light at concentrations of 125, 250, 500, 750 and 1000 ml/L of seaweed extract and control treatment (no treatment) with 8 replications. According to the results of the first experiment, the greatest leaf width and stem diameter were observed in the presence of blue light and the greatest leaf diameter was observed in the presence of red-blue combined light. In the second experiment, conducted 60 days after the second experiment, the greatest number of flower buds per plant and stem length were observed under the white light condition. Also, in Arena cultivar, concentrations of 500 and 750 ml/L of seaweed extract led to a greater number of flower buds per plant than the control treatment. Increases in morphological traits of leaf width and diameter, leaf length, and internode length were observed upon exposure to blue light and red-blue combined light in both of the experiments. Enhancements in most of the morphological traits in both experiments was observed in the presence of blue light and red-blue LED combined light. According to the results of this study, it seems that production of Arena cultivar in the presence of blue light and a concentration of 500 ml /L of seaweed extract is more feasible than the other cultivar and light and seaweed amendments.