Growing Micropropagated Kappaphycus Alvarezii and Mitigating Ice-Ice Disease and the Incidence of Macro-Epiphytes Using an Extract of the Brown Alga Ascophyllum Nodosum at Three Different Seeding Techniques

A phyco-biostimulant from the brown alga Ascophyllum nodosum has been widely used in agricultural crops for decades. However, it was recently discovered that the same extract can be successfully applied in the micropropagation and field cultivation stages of eucheumatoids. The present study tested the efficacy of an alkali extract from A. nodosum (aka AMPEP) on Kappaphycus alvarezii with the aim of enhancing daily growth rate, as well as to mitigate the prevalence of ice-ice disease and macro-epiphytes, using three different seeding methods (i.e., double-looping DL, tubular-netting TN and ribbon tying RT, vis-à-vis water quality parameters. Seedlings were dipped in soluble extract powder made up to 1 g L−1 AMPEP for 1 h prior to out-planting in the sea. A total of three growth cycles, each of 45 days, from November—June (representing the dry months) were followed. The daily growth rate (