LAUSR

The aim of this research is to analyze potency and generate organic fertilizer with noneconomic seaweed as material which is bioecologically environment-friendly to stimulate Gracilaria verrucosa production. By utilizing inexpensive and bioecologically beneficial material, it is expected to increase the growth, production, and repair the quality of Gracilaria verrucosa. The specific target of this research is to analyze the effectivity of an-organic fertilizers (urea) with seaweed-based liquid organic fertilizer. The hormone growth of generated urea and seaweed liquid fertilizers is analyzed, including auxin, gibberellin , cytokinin , as well as nutrient (macro and micro). Moreover, the fertilizer is tested on Gracilaria verrucosa. Several noneconomic seaweeds ( Codium sp., Ulva sp., Padina sp., Amphiroa sp.) are found in waters area of Sulawesi Tengah. Based on laboratory testing result, it shows that organic fertilizer which has good potency by looking at N, P, and K contents is organic fertilizer Ulva sp., with content of N (0.45 mg/L), P (7.67 mg/L), and K (11.06 mg/L). The result of the research shows that there are apparent differences between the tested treatment ( p  < 0.05) on Gracilaria sp., growth, and the highest testing on giving liquid fertilizer Ulva sp. (71.0 g) with dose 400 mL/15 L water. The result of Gracilaria verrucosa quality by using liquid fertilizer Ulva sp. is 40.89%, urea fertilizer 38.62%, and without fertilizer 32.57%. The hormone content of Ulva sp. growth is IAA (0.3961 ppm), gibberellin (36.9595 ppm), and kinetin (3.3718 ppm), and urea fertilizer contains IAA (0.4063 ppm), gibberellin (30.2047 ppm), and kinetin (0.0717 ppm).