Influencia del riego superficial por goteo sobre la Verticilosis del olivo en condiciones de ambiente natural

Resumen

The prevalence and incidence of Verticillium wilt of olive (VWO) are higher in irrigated olive orchards than dryfarming ones in Andalusia (Southern Spain). It is generally accepted for other Verticillium dahliae host plants that increasing the amount of water and irrigation events will increase the disease incidence and/or severity. To reach this knowledge about VWO is essential for an integrated disease management strategy in Andalusia. This study was aimed to assess the effects of water content in the soil and drip-irrigation frequency on the progress of VWO and the temporal dynamics of the fungus in soil in a cultivar-isolate framework suitable for the development of the disease. To achieve those objectives, a natural environmental conditions pot-experiment was placed at the experimental farm of IFAPA "Alameda del Obispo" in Cordoba (Southern Spain). 'Picual' (susceptible) potted olive plants (one per pot) grew in a soil mixture infested or not (control) by propagules of one defoliating V. dahliae isolate belonging to the highest virulent group to olive (lethal). A surface drip irrigation system with 4 droppers per plant supplied two rates of water content in the soil (high and low) and three irrigation frequencies (daily, weekly, and daily-cum-weekly). Verticillium wilt symptoms were periodically diagnosed and assessed, and inoculum levels of V. dahliae in soil were monitored regularly. Preliminary data collected in the spring to fall period showed that VWO was affected stronger by the irrigation frequency than the rate of water content in the soil. The inoculum levels of V. dahliae in soil did not explain the development of Verticillium wilt during the experimental period.