Combination of vermicompost fertilizer, carbon, nitrogen and phosphorus on cell characteristics, growth and quality of agar Seaweed Gracilaria verrucosa

Seaweed is one of the marine and fishery commodities which encounter many problems in spurring growth and obtain high quality of agar, especially in Takalar District South Sulawesi Province, Indonesia. The combined use of vermicompost organic fertilizer, carbon, nitrogen and phosphorus are a source of much-needed nutrients by the seaweed to expand the network of cells that affect the growth and quality of agar. The purpose of this study was to see the influence of the combination of vermicompost fertilizer, carbon, nitrogen and phosphorus on the characteristics of the cells, the growth and the quality of agar seaweed G. verrucosa. This study was conducted for 42 days. The treatment ratio of carbon%: nitrogen%: phosphorus% are 93:6:1, 92:7:1, 91:8:1, 90:9:1, 89:9:2 and 88:10:2. Treatment ratio of fertilizer was best obtained at treatment 91:8:1, the cell number 39-104 mm^-2, cell size from 25.189 to 400.213 1/4m, cell shape oval and cell wall thickness, weight biomass 0.65 to 2.14 g, the daily specific growth from 2.29 to 7.99%, thallus length from 2.5 to 3.8 cm, quality of agar from 9.98 to 26.52%, quality of agar viscosity of 43-90 cps, quality of agar gel strength of 49.0 to 80.4 g/cm². The range of water quality during the study was 25-26°C for the temperature, water salinity was 25 ppt, pH 7.50 to 7.87, carbon 734.51 to 4754.12 ppm, nitrogen from 14.91 to 98.91 ppm, and phosphorus of water from 19.84 to 38.39 ppm.