EFFECTS OF PHOSPHORUS IN THE WASTEWATER FROM INTENSIVE CATFISH FARMING PONDS ON THE GROWTH AN PHOSPHORUS UPTAKE OF Hymenachne acutigluma (Stued.).

Hymenachne aquatic grass, Hymenachne acutigluma was planted in the wastewater from intensive striped catfish (Pangasianodon hypophthalmus) cultivating ponds containing 2.1 mg N/L, which was enriched with a serious of inorganic phosphorus (P) concentrations. The experiment was arranged in a completely randomized design with three replications in the net house for 42 days. The results showed that P concentrations did not significantly affect the growth of Hymenachne. The presence of high P concentrations resulted in the increase of P content in plant tissues leading to higher P absorption at the P levels of 8 and 10 mg P/L. H. acutigluma removed 12.1-27.6% P from 88.3-95.9% P in the wastewater of striped catfish pond. This result indicated the low concentrations of N (2.1 mg N/L) and of 1-10 mg P/L were not optimal for the growth of H. acutigluma. [ABSTRACT FROM AUTHOR]