Efficacy of Fermented Garlic and Vinegar-Based Biopesticide for the Management of Sweetpotato Wilt Caused by Fusarium oxysporum f. sp. batatas

Abstract

This study aimed to determine possible biopesticides against Fusarium wilt in sweetpotato using locally available materials. The fungicidal efficiency of fermented garlic and vinegar combinations were tested against Fusarium oxysporum f. sp. batatas through bioassay, as a soil amendment, and as a spray on infected field plants. Three different local kinds of vinegar, namely sweetpotato vinegar, coconut water (sukang puti) and cane vinegar produced comparable inhibition zones in vitro. Garlic and wood vinegar combination produced the least inhibition zone against the fungus but was the most effective soil amendment. Soil with Trichoderma harzianum recorded the highest herbage weight and length but did not translate to storage root yield. Instead, garlic and wood vinegar or sweetpotato vinegar had the highest storage root yield. Its efficacy was comparable with other amendments such as Trichoderma harzianum and lime. The soil amendments enhanced herbage and root yield in the study despite favorable conditions for disease development. When used as a spray, garlic extract combined with either wood vinegar, sweetpotato, coconut water, or cane vinegar was found effective in controlling Fusarium wilt, as verified in two trials giving more than 50% disease control compared to untreated plants. Results showed that fermented garlic, regardless of local vinegar formulation, is an effective biopesticide in managing Fusarium wilt of sweetpotato.