ABSTRACT
Black soldier fly frass and its derivatives as biofungicide to control Fusarium wilt in bananas

Jia Xin Ong1, Nur Baiti Abd Murad1, Siti Rasila Ainaa Mohd Rasli2, Mohd Rezuwan Shah Zakaria2, Shanmugaprakasham Selvamani2, Hesham Ali El-Enshasy3, Martin Jose Zorrilla4, and Noor Baity Saidi1*
 
Fusarium wilt disease has greatly threatened banana (Musa acuminata Colla) plantations worldwide. Sustainable approaches utilizing bio-based agricultural products are a promising alternative to managing the disease. In this study, the potential of composted black soldier fly (BSF; Hermetia illucens [Linnaeus], 1758) frass and its fermented liquid derivative as biofungicides against the Fusarium wilt pathogen, Fusarium oxysporum f. sp. cubense tropical race 4 (Foc TR4), were investigated in vitro and in vivo. The minimum inhibitory concentration (MIC) of sterile (filter-sterilized) and non-sterile filtrates prepared from composted BSF that inhibit Foc TR4 spores was recorded at 40% and 25% (v/v), respectively. However, only the non-sterile filtrate (50%, v/v) achieved the fungicidal effect against Foc TR4 spores and mycelium in the in vitro inhibition assay. The in vivo pot experiment showed that preventive treatment of soil with the composted BSF frass in combination with the fermented liquid derivative reduced the Fusarium wilt disease index to 47.66%. Analysis of the microbial community in the composted BSF frass revealed a high abundance of Firmicutes (64%) and Actinobacteriota (23%) phyla, whereas Proteobacteria (44%), Planctomycetota (19%), and Bacteroidota (18%) dominated the fermented liquid derivative, which likely explains the observed disease-suppressing effects. This study pioneers the exploration of BSF frass as a biofungicide against Fusarium wilt in bananas, revealing that composted BSF frass and its fermented liquid derivative could serve as effective, sustainable alternatives to conventional fungicides in managing the disease.
Keywords: Biological control, BSF, Foc TR4, Fusarium oxysporum f. sp. cubense, Hermetia illucens, Musa acuminata, suppression.
1Universiti Putra Malaysia, Faculty of Biotechnology and Biomolecular Sciences, 43400, Serdang, Selangor, Malaysia.
2Nutrition Technologies, R&D Biotechnology Division, 79150 Iskandar Puteri, Johor, Malaysia.
3Universiti Teknologi Malaysia, Institute of Bioproduct Development, 81310 UTM, Johor Darul Ta’zim, Malaysia.
4Nutrition Technologies, 048423, Singapore, Singapore.
*Corresponding author (norbaity@upm.edu.my).