The application of disinfectants through drip irrigation could be a feasible practice against verticillium wilt (Verticillium dahliae) of olive. OX‐VIRIN (activated peroxide) and OX‐AGUA AL25 (quaternary ammonium compounds) are two disinfectants that have shown efficacy against V. dahliae in irrigation water and potential for reducing the disease in young olive plants. In this work, various post‐planting application strategies incorporating OX‐VIRIN (once a month, or twice a month on alternate or successive weeks) or OX‐AGUA AL25 (once a month, or twice a month on alternate weeks) were assessed for their effect on V. dahliae in soil, disease in olive trees, and olive yield, in a 2‐year pot‐experiment under natural environmental conditions. The disinfectants were injected via metering pumps into a drip irrigation system that irrigated olive trees planted in V. dahliae‐inoculated soil. All the application strategies significantly reduced the total inoculum density in soil compared to controls with no disinfectants and noninoculated soil. The microsclerotia density was also significantly reduced in disinfested soils by 73.6–86.8%, depending on the strategy. The symptoms and infection incidence were always lower in treatments subjected to disinfestation. The treatment with OX‐AGUA AL25 applied twice a month on alternate weeks most reduced the symptoms (by 53.0%) and colonization index (by 70.8%) with respect to untreated water control. This soil disinfestation also significantly strengthened the symptom remission. Tree growth and production were negatively affected by soil inoculation (reduced by 45.6% and 88.7%, respectively), but not so by disinfectants, which even relieved the reduction in inoculated soils, especially when OX‐AGUA AL25 was applied.

Controlling Verticillium dahliae through irrigation systems should be an important measure within integrated management of verticillium wilt of olive in Spain. Pathogen content of water infested by V. dahliae conidia and sclerotia can be diminished following in vitro treatments with the disinfectants OX‐VIRIN and OX‐AGUA AL25. Three concentrations per disinfectant were assessed for their effectiveness under operational conditions of modern irrigated olive orchards. Sterilized potted soil was drip‐irrigated with conidia‐ or sclerotia‐containing water that was pumped from a storage tank and disinfected (or not, control) within the pipelines via metering pumps. The trial was carried out in autumn and spring for each type of propagule infesting the water. The inoculum dispensed through drippers and the total inoculum density accumulated in soil were estimated. Furthermore, the treated residual inoculum in soil was assessed for pathogenicity on olive plants. Conidial incorporation in soil was prevented by most disinfectant treatments in spring; while for sclerotia, prevention was observed only at the highest OX‐VIRIN (51.2 mL L−1; in both seasons) and OX‐AGUA AL25 (11.27 mL L−1; in autumn) concentration. The remaining disinfectant treatments reduced conidia and sclerotia accumulation in soil by over 99% and 95%, respectively. Season particularly impacted the efficacy of lower concentrations. Expression of symptoms was not observed in olive plants grown in previously treated soils. The infectivity of the residual inoculum present in some treated soils was prevented, markedly reduced or limited to the roots. These results provide a novel, interesting and feasible approach in the management of the disease.