Semi-Mechanized Sewing Technique Engineered for Small-Scale Planting of the Red Seaweed Kappaphycus alvarezii (Doty)

This study introduced a new small-scale semi-mechanized planting method for Kappaphycus alvarezii (Doty) and compared its efficiency to traditional methods. A semi-mechanized sewing (S-MS) device was designed to speed up the planting process using affordable materials. To validate the S-MS model, three different cultivation systems (S-MS method, tie-tie, and tube-net systems) using two color morphotypes of K. alvarezii were implemented, each in triplicate. The experiment spanned 40 days. Water quality and technical indicators were monitored, and data on material consumption and productivity were analyzed. The exclusive S-MS mechanism was successfully completed. The S-MS significantly reduced rope usage by 4.3 times per each propagule sewn to the main cable and planting time (S-MS = 1 min 12 s per meter) compared to the traditional method (tie-tie = 1 min 48 s per meter). Final biomass varied among treatments (p < 0.05), with the S-MS method showing a higher final biomass (15.26 ± 0.88 kg) with olive green K. alvarezii. The average daily growth rates (6.38%) were higher for the S-MS method with olive green K. alvarezii. The S-MS technique offers cost and time savings for seaweed farmers, making it a viable alternative to traditional methods, showed comparable productivity to tie-tie but superior efficiency and resource economy.