Molluscicidal activity of the aqueous extract of garlic (Allium sativum L.) bulb against golden apple snail (Pomacea canaliculata L.)

Abstract

The search for efficient, organic, and environment-friendly molluscicide that could minimize the spread of the invasive Golden Apple Snail (Pomacea canaliculata) in the Philippines is still on going. To investigate the molluscicidal activity of garlic (Allium sativum) towards the rice pest (Pomacea canaliculata), this study employed Complete Randomized Design in 3 trials (n=630 snails) to test the efficacy of Aqueous Garlic Extract [AGE] under five experimental treatments (T1=10ppm AGE; T2=8.75ppm AGE; T3=7.5ppm AGE; T4=6.25ppm AGE and T5=5.0ppm AGE) and two control groups (Positive Control=Niclosamide [Snail ShatterTM] and Negative Control= distilled H2O. After 48h experimental period, mortality data were analyzed using One Way ANOVA (p<0.05) and post hoc analysis (Tukey’s test) while Probit analysis was employed to determine toxicity level of AGE at LD50 and LD90. Results showed that there is a direct relationship between AGE and snail mortality, suggesting that all treatments exhibited molluscicidal properties. However, T1 and T2 were reported to have a comparable molluscicidal effect to that of the commercially-available molluscicide (NiclosamideTM). Toxicity level (LD50) was found to be at 4.007ppm while LD90 is 7.602ppm. As evidenced by the laboratory experiment results, this study concludes that the best AGE concentration against the target mollusk (Pomacea canaliculata) is T3=7.5ppm. For future research, this study recommends the use of similar AGE concentrations to P. canaliculata and economically important, non-target organisms (Tilapia, Oreochromis niloticus) under field trials.