Evaluation of the efficacy of commercial disinfectants against Fusarium oxysporum f. sp. cubense Race 1 and Tropical Race 4 propagules

Abstract

Panama disease caused by Fusarium oxysporum f. sp. cubense (Foc) has devastated banana production worldwide. This work aimed to determine effective disinfectants against two races of Foc, race 1 and tropical race 4 (TR4), for implementation with on-farm biosecurity procedures against this disease following the outbreak of TR4 in North Queensland in 2015. A total of 32 commercial disinfectants were screened and their activity was assessed after ≤ 30 sec, 5 min, 30 min and 24 hr of contact with a Foc suspension containing 105/ml chlamydospores without and with soil added (0.05 g/ml). Of the disinfectants tested, the quaternary ammonium compounds containing ≥ 10% active ingredient were found to be the most effective against both Foc races. These products, when used at a 1:100 dilution, completely inhibited the survival of all Foc propagules across all the contact times regardless of the absence or presence of soil. The bioflavonoids product EvoTech 213 and bleach (10% sodium hypochlorite) used at a 1:10 dilution also eliminated all Foc propagules across all the contact times. None of the detergent-based or miscellaneous products tested were completely effective against both Foc races even used at a 1:10 dilution. Soil decreases the efficacy of disinfectants and therefore must be removed from contaminated items before treatments are applied.