Efficacy of Disinfectants against f. sp. Tropical Race 4 Isolated from La Guajira, Colombia.

Banana, the main export fruit for Colombia, is threatened by Fusarium wilt (FWB), caused by f. sp. (), tropical race 4 (TR4). Pathogen containment through disinfecting tools, machinery, shoes, and any means that may carry contaminated soil particles with proper disinfectants is at the forefront of disease management. In this study, the biocide efficacy of 10 commercial quaternary ammonium compounds (QACs) products and one based on glutaraldehyde (GA) were evaluated on both reproductive structures (microconidia and macroconidia) and survival spores (chlamydospores) of TR4 (strain 140038) isolated from La Guajira, Colombia. QACs were evaluated at 1200 ppm and two exposure times: <1 and 15 min in the absence or presence of soil. For GA disinfectant, four different concentrations (500, 800, 1200, and 2000 ppm) were evaluated at both contact times in the presence of soil. In the absence of soil, all QACs showed 100% biocidal efficiency against microconidia, macroconidia, and chlamydospores at both <1 and 15 min. The presence of soil decreased the efficacy of disinfectants, but some of them, such as QAC3_1st, QAC7_4th, and QAC5_4th, showed 98%, 98%, and 100% efficacy against TR4 chlamydospores, respectively, after <1 min of contact time. For instance, the GA-based disinfectant was able to eliminate all TR4 propagules after 15 min for all concentrations tested.