The seasonality and economic feasibility of cultivating Kappaphycus alvarezii in Panagatan Cays, Caluya, Antique, Philippines

Vegetative thalli of brown and green Kappaphycus alvarezii were cultivated in Panagatan Cays, Caluya, Antique, Philippines, over 60- and 90-day period s using hanging-long line (HU fixed off-bottom (FB), and hanging long line- fixed off-bottom (BL-FB) methods to determine the daily growth rate and yie ld. A completely randomized design experiment with six replicates of 5-m li ne cultivation rope was used in the study. An economic analysis was prepare d to determine the viability of the culture systems used. To determine the effect of strain, culture technique, culture days and culture month on the daily growth rate and yield, a combination of these different factors was t reated as a single treatment. Results show that at 60-day culture period, d aily growth rate and yield in all techniques were lowest in July-August and highest in January-February. Higher growth rate (2.3-4.2% day(-1)) and yie ld (3.6-15.8 fresh weight kg m(-1) line(-1)) were obtained from September t o February. Significant differences (P < 0.05) in growth rate and yield wer e determined between culture months. At 90-day culture period, there were n o significant differences in growth rate and yield between culture months; however, a significant difference was found between culture techniques. The average production (dry weight kg crop(-1)) of K. alvarezii when grown at 60-day culture period during lean and peak months using HL, FB and HL-FB te chniques ranged from 421 to 3310 kg with HL-FB the highest and FB the lowes t. Net income, return on investment (ROI) and payback period were all posit ive during peak months, but negative values were obtained during lean month s. Only seaweed grown on HL technique during the peak months at 90-day cult ure period showed positive income, ROI and payback period. The seasonality of cultivating K. alvarezii is shown in this present study. This paper furt her shows the best culture technique to be adopted at certain months of the year to produce the highest yield and income. (C) 2001 Elsevier Science B. V. All rights reserved.