The effect of surface sterilants on spore germination of Fusarium oxysporum f. sp. cubense tropical race 4

- We analysed three surface sterilants for effectiveness against Fusarium oxysporum f. sp. cubense tropical race 4 spores.
- Complete inhibition of Foc TR4 microspores can be achieved.
- Sporekill® was the most effective sterilant assessed.
- The effectiveness of sterilants generally decreased under tropical field conditions.

Fusarium wilt of banana is a devastating disease caused by Fusarium oxysporum f. sp. cubense (Foc). The 'tropical' race 4 strain (Foc TR4) has a significant impact on the banana industry worldwide. To prevent this soilborne disease from spreading, the best practice is to minimise movement of infested soil. Investigations were made on three products, Farmcleanse®, Sporekill® and Domestos®, to determine their suitability as surface sterilants for use in footbaths and on machinery. Assessments involved analysing the rates of microconidia germination, following treatment with fresh preparations of each product, at a range of concentrations and exposure times; and also with preparations of each, after exposure to heat and sunlight, for a range of times. Sporekill® was a better surface sterilant than Farmcleanse® and Domestos®, preventing germination of microconidia after the minimum exposure time of 30 s. Sporekill® was also able to inhibit microconidia germination after 6 months of exposure to heat and sunlight. This study demonstrated that Sporekill® is more effective than Farmcleanse® in inhibiting the germination of Foc TR4 spores, and may be beneficial for use in footbaths and the general disinfestation of machinery contaminated with Foc TR4.