Investigation on usability of onion (allium cepa) and garlic (Allium sativum L.) wastes in prevention of rainbow trout fungal disease

In this study, usability of waste parts (skin and stem) of onion (Allium cepa) and garlic (Allium sativum) plants in treatment of fungal diseases (Saprolegnia parasitica) that occur on economically important fish species rainbow trout (Oncorhynchus mykiss) and its eggs was investigated. In the study, aqueous methanolic extraction of skin and stem parts of onion and garlic plants were performed. For this purpose, identification of fungus (Saprolegnia parasitica) species and MIC values were determined using obtained extracts. 5 different concentrations (0 g/L (control), 0.4 g/L, 0.8 g/L, 1.6 g/L, 3.2 g/L) of the extracts on the live material were investigated via bathing method. These extracts were applied only once after fertilization. According to the results of the study, the number of eggs in groups showing fungus formation was compared with the control group, garlic stem (0.4 g / L) and onion skin were relatively low, but no statistically significant difference was found. Garlic skin (0.4 g/L, 0.8 g/L, 1.6 g/L) groups had lower fungus formation and higher survival rates compared to the control group. No differences were observed in garlic stem (3.2 g/L) and garlic skin (3.2 g/L) groups in comparison with the control group. Based on the study data and observations, there was no change in the development of the eggs, the development of the larvae and larval stages, and growth in fish compared to the control group. It has been concluded that the waste parts of garlic and onion plants (stem and skin) can be used in the treatment of fungal disease on rainbow trout and eggs.