Abstract:
Biological waste from fish processing and post-harvest handling is an environmental issue and the
conversion of fish waste into organic fertilizer has been identified as an eco-friendly approach to
address it. Therefore, this study was done to evaluate the effectiveness of liquid extract from fish
waste as a liquid fertilizer (LFE) and its effects on the growth performance of the micro-propagated
ornamental aquatic plant Cryptocoryne wendtii. Three levels of LFE, 0.25 gL-1, 0.50 gL-1, and 0.75 gL 1 were compared with the recommended level of inorganic fertilizer (0.5 gL-1 Albert solution) as the
control for six weeks. Twenty-four micro-propagated plants were potted in individual plastic cups
and plants were randomly allocated to 12 glass tanks (two pots per tank) with the respective level
of fertilizer (40 L). Complete water exchange with the relevant level of fertilizer was done at two
weeks intervals and, NO3−and PO4
3−concentrations of water were measured before water was
renewed. In this study, measurements of initial and final plant wet weight, total plant height, stem
height, rhizome height, root length, leaf length and width, leaf area, and the number of leaves and
shoots were taken. Additionally, Relative Growth Rate (RGR), Leaf Area Ratio (LAR), and Net
Assimilation Ratio (NAR) were calculated for plants in each treatment. These parameters were
compared using one-way ANOVA. Plant wet weight, total plant height, rhizome height, leaf width,
and leaf area of plants treated with 0.75gL-1 LFE showed significantly higher growth performance
compared to the control. Significantly higher RGR, LAR, and NAR were reported for 0.75gL-1 LFE
treatment followed by 0.5gL-1 and 0.25gL-1 LFE treatments. The results of this study revealed that
liquid fish waste extracts at the concentration of 0.75gL-1 can be used as a liquid fertilizer for
Cryptocoryne wendtii without compromising the growth performances when compared to the
recommended level of inorganic fertilizer.
