Effects of Fish-derived Liquid Fertilizer on Growth of Wolffia globosa during the Monsoon Season

Introduction Wolffia globosa has been considered a functional food formulation due to its excellent nutritional value and rapid growth. Organic liquid fertilizer from fish (OLF) has been used as a source of nutrients for plant growth. However, there is limited information regarding the use of OLF for the cultivation of W. globosa . This research aimed to cultivate W. globosa using OLF during the monsoon season. Methods Two outdoor experiments were conducted during the monsoon of 2025. Experiment 1 comprised eight treatments of OLF, being 0, 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, and 3.5 mL/L. The plant was grown on rainwater in 11-L plastic containers covered with 50% black shade cloth and harvested at 11 days. Experiment 2 resembled the cultivation system in small-scale farms and comprised three treatments: 1.5, 2.5, and 3.5 mL/L, with OLF added during the experiment. OLF was made from fish waste collected from a local supermarket. The plant was grown on tap water in open 1.2-m diameter cement ponds. Biomass (g) was monitored every five days for 30 days. Daily rainfall was collected during the two experiments. Results Biomass gain was lower in Experiment 1 (1.8-2.4 times the starting mass) than in Experiment 2 (2.6-4.1 times the starting mass). Biomass was greater at higher rates of OLF in both experiments, although differences were not always statistically significant;biomass per unit area (g/m 2 ), average daily biomass gain (g/day), and daily productivity (g/m 2 /day) were greater at higher rates in Experiment 2. Biomass per unit area exceeded 2 kg/m 2 in treatment 3.5 mL/L after 30 days. In the three treatments, average daily biomass gain was the highest at 15 days (48.85-66.76 g/day), while daily productivity was the highest at five days (89.08-105.77 g/m 2 /day). Discussion OLF as high as 3.5 mL/L could fertilize W. globosa under the conditions of this study. Conclusion It is practical to cultivate W. globosa using OLF without changing media for a 30-day period. However, farmers may harvest the plant at 15 days, as average daily biomass gain reached a peak, and then restart the whole process of cultivation with the new media.