Poster Presentation Science Protecting Plant Health 2017

Effects of commercial disinfectants on the survival of Fusarium oxysporum f.sp. cubense Race 1 and Tropical Race 4 propagules (#152)

Vu Tuan Nguyen 1 , Peter Trevorrow 2 , Kathy Grice 2 , Lucy Tran-Nguyen 1
  1. Northern Territory Deparment of Primary Industry and Resources, Berrimah, NORTHERN TERRITORY, Australia
  2. Agri-Science Queensland, Department of Agriculture and Fisheries, Mareeba, Qld, Australia

Panama disease caused by Fusarium oxysporum f.sp. cubense (Foc) Race 1 (R1) and Tropical Race 4 (TR4) is one of the most destructive banana plant diseases worldwide. One of the best practices to manage the disease is to implement decontamination procedures using disinfectants on farms to restrict the movement of Foc. This work aimed to determine the most effective disinfectants against both Foc R1 and TR4 to form part of on-farm biosecurity procedures. A total of 20 disinfectants were screened and their activity was assessed after ≤ 30 sec, 5, 30 min and 24 hrs of contact with Foc in the absence and presence of soil (0.05 g/ml). Of the disinfectants tested, the quaternary ammonium compounds that contain > 12% active ingredient (ai) of didecyl dimethyl ammonium chloride (DDAC) were found to be the most effective against both Foc races. These products when used at a 1:100 dilution, reduced Foc survival to a “zero” detectable level across all the contact times with or without soil present. Bleach (10% sodium hypochlorite) and two bio-flavonoid products diluted to this rate were also effective in eliminating Foc but longer treatment times (≥30 mins) were required. Two detergent-based products failed to eliminate propagules of both races even at a dilution rate of 1:10 and after 24 hrs of treatment, although they could suppress Foc colony development. Significantly (P<0.05) greater numbers of Foc colonies developed in some treatments with soil than those without, suggesting that the presence of soil decreases the activity of certain disinfectants. Based on these findings, this study suggests that the DDAC products (> 12% ai) diluted to the rate of 1:100 can form part of decontamination procedures against both Foc R1 and TR4. Excess soil needs to be washed off contaminated items before treatment to maintain the efficacy of disinfectants.