Effect of Some Synthetic Fungicides on the in vitro Growth of Colletotrichum gloeosporioides , Causative Agent of Cashew Tree Anthracnose in C?te d?ivoire

摘要

Background and Objective: Anthracnose is the most common disease of tropical and sub-tropical cultures. It is the main disease in cashew orchards of C?te d?Ivoire. The objective of the study was to screen in vitro effective chemicals fungicides to control the disease. Materials and Methods: The synthetic fungicides Azoxystrobin, Carbendazim, Prochloraz, Propiconazole Mancozeb, Thirame, Cymoxanil+Mancozeb and Metalaxyl-M+Copper oxide have been assessed for mycelial growth , sporulation and spore germination of Colletotrichum gloeosporioides , the fungus causative agent of cashew tree anthracnose in Cote d?Ivoire. Each Fungicide was incorporated into a Potato Dextrose Agar (PDA) medium at six concentrations (0.1, 1, 5, 10, 25 and 50 ppm) and data collected were submit to one way analysis of variance (ANOVA) with Statistica software 7.1 version. Results: These fungicides and combinations of fungicides have shown in vitro fungitoxic activity more or less significant on the three life stages of the pathogen. Among the fungicides tested, Carbendazim and Prochloraz were more effective on fungus growth with similar properties. Both fungicides showed very toxic activity by significantly reducing mycelial growth at the lowest dose of 0.1 ppm. Carbendazim had fungistatic and fungitoxic properties, respectively at doses of 1 and 5 ppm while for Prochloraz they were, respectively 5 and 10 ppm. Carbendazim and Prochloraz have been highly toxic to Colletotrichum gloeosporioides compared to other fungicides because they have IC₅₀ less than 0.1 ppm. Conclusion: All fungicides tested can be therefore regards as a prospective means of limiting mycelial growth , spores germination and protecting cashew from Colletotrichum gloeosporioides with Carbendazim, Prochloraz, Propiconazole and Azoxystrobin as the bests.