Toxicities of Common Fungicides and Their Mix Formulations to Mango Anthracnose Pathogen Colletotrichum gloeosporioides

Toxicitis of ten fungicides to mango causal agent Colletotrichum gloeosporioides were tested using mycelial growth rate method. The results showed that prochloraz 45% EW had the strongest of toxcity with the minimum EC50 value of 0.01 mg/L among 10 fungicides. flusilazole 40% EC, propiconazole 25% EC, difenoconazole 95% TC or iprodione 50% WP had stronger toxicities with the EC50 values of 0.03 to 0.81 mg/L. myclobutanil 96% TC, triadimefon 15% WP, chlorothalonil 96% TC and kresoxim methyl 30% WP had the low toxicities with the EC50 values of 4 to 65.2 mg/L, while mancozeb 50% WP had the lowest toxicity with the EC50 values of 105.0 mg/L. Among 8 mix formulation of two of these fungicides, toxicity indexes of the mix of prochloraz and triadimefon in tested ratios were more then 1 with the highest index of 1.2 at the optimun ration at 6:4, its co-toxicity index (CTC) was 166.61, which was significantly higher than 100, indicating a strong synergistic action between these two fungicides. No previously synergistic action was found between other 7 mixes.