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Leaf spots and rust are the most destructive diseases of peanut in Tropical Africa, but it has shown thatAkanthomyceslecaniiisknown ashyperparasiteof rustandleaf spots fungi. Previous studies have investigated on the use of conidia ofA.lecaniiin biocontrol of these diseases. However, the conidia are influenced by temperature and relative humidity, which could result in low efficiency of biocontrol agents in natural conditions. The use of secondary metabolites could help to fight against the plant diseases in natural conditions. Thus, we sprayed peanut plants with culture filtrates from 21-day-old cultures of two strains ofA. lecaniigrown in potato dextrose broth, to assess their efficiency against leaf spots and rust diseases innatural conditions. A susceptible variety SH470P and a moderately susceptible varietyPC79-79 of peanut to rust and leaf spots diseases were used. Our findings revealed thatA. lecaniiculture filtrates have significantly reduced the severity of rust and leaf spots diseases in SH470P only. In SH470P, the lowest severity of leaf spots in 2020 (59.26%) and 2021 (48.10%) were recorded in plots sprayed with culture filtrates ofA. lecanii. The lowestseverity of rust (29.60%) was recorded in the plots sprayed with theA. lecaniiculture filtrates in 2021 in SH470P. From our findings, the use ofA. lecaniiculture filtrates is a promising alternative in the control of peanut rust and leaf spots. But, further studies are required to determine the effective doses and active secondary metabolites against these diseases. |
