Application of brown seaweed-derived agro biostimulant to the commercial farming of the red seaweed Kappaphycus alvarezii in India: Growth enhancement and production of quality raw material

Currently global seaweed industries are facing issue with availability of raw material for processing of carrageenan due to low growth of current planting material. Use of biostimulants in seaweed cultivation is recently paid more attention due to their proven biostimulatory effect, of which, Ascophyllum marine plant extract powder (AMPEP) is a well proven biostimulant to improve the growth and quality of Kappaphycus alvarezii biomass. Hence, 500 kg of AMPEP was purchased and studied its impact on the commercial farming of K. alvarezii from April 2018 to January 2022 in India. Vegetative propagule of K. alvarezii were dipped in an AMPEP with concentration range of: 0.025, 0.05, 0.10, 0.15, 0.20 and 0.25 % for 30, 60, 90 and 120 min. Before out-planting on rafts in shallow coastal water and found that K. alvarezii responded well to a 0.1 % solution with dipping time of 60 min. The percentage of average daily growth rate (ADGR%) of AMPEP-treated plant in a 45 d grow out period was 3.50 ± 0.50 % vs a control of 1.75 ± 0.25 % for the summer and pre-monsoon months (p