CULTIVATION AND CARRAGEENAN YIELD AND QUALITY OF KAPPAPHYCUS-ALVAREZII IN THE WATERS OF VIETNAM

The carrageenan-producing red alga Kappaphycus alvarezii (Doty) Doty w as brought to Vietnam from Japan in 1993. Branch fragments of this spe cies were cultivated in a pond, lagoon, inlet and offshore in Vietnam for the first time. The best daily growth rate (DGR) of plants grown i n the lagoon area attained 9-11% day(-1) in May to June (cold season). The water temperature and salinity in this area ranged from 27.2-32.4 degrees C and 31.4-33.7 degrees C, respectively. DGR of plants grown in the inlet ranged from 7 to 9% day(-1) in June. Grazing by fish has been observed to occur in this area. The DGR of plants grown in the po nd ranged from 5-6% in January-July, but decreased to less than 4% day (-1) in August (hot season). K. alvarezii in Vietnam showed a carragee nan yield of 18.8-24.6% and gel strength of 1566-1712 g cm(-2). These values are similar ones obtained from K. alvarezii cultivated in the P hilippines and Indonesia.