Roses Growth and Flowering Responding to Concentration and Frequency of Seaweed (Sargassum crassifolium L.) Liquid Extract Application

Abstract

Rose is a popular cut flower in Sri Lanka and mainly cultivated for the export market. An experiment was conducted at the Crop Farm, Eastern University, Sri Lanka to assess the effects of seaweed liquid extract on growth and flowering of roses (Rosa sp.) from June to September 2018. Seven treatments of seaweed liquid extract applications (10% once a week (T1), 10% twice a week (T2), 20% once a week (T3), 20% twice a week (T4), 30% once a week (T5), 30% twice a week (T6) and distilled water (T7- control)) were applied at completely randomized design with ten replications. Plant height, leaf area, plant biomass and number of flowers were significantly higher in T3. Once a week application of 20% seaweed liquid extract had the potential to increase the plant height, leaf area, plant biomass, number of flowers and dry weight of flowers in this experiment. It might be due to the presence of nutrients and the growth promoters in the S. crassifolium L. seaweed extract and optimum concentration of seaweed extract received by plants at T3.From this experiment, it could be concluded that once a week application of 20% seaweed liquid extract is suitable for promoting growth and flowering of roses.