Delayed Development of Resistance to QoI Fungicide in Venturia inaequalis in Israeli Apple Orchards and Improved Apple Scab Management Using Fungicide Mixtures

Quinone outside inhibitors (QoI) fungicides group were introduced for commercial use against apple scab (Venturia inaequalis) in Israel 1997. Unlike other regions the world, which resistance of V. inaequalis to QoI was observed within 3–5 years use, it only occurred after 14 use. Field trials conducted between 2007 and 2017 showed a significant reduction susceptibility QoIs northern since 2011. The delay development is related limited fungicidal sprays resulting from unfavorable conditions pathogen. Of 28 isolates collected infected leaves or fruits orchards Israel, 27 resistant fungicide Kresoxim-methyl. Amplification CYTB gene sequencing G143A mutation region confirmed all QoIs. Resistance demonstrated orchard, vitro molecular-based study, forced growers avoid using scab. We show that foliar applications tank mixtures systemic plus captan prepacked improved efficacy can be used as strategic approach management, including has been detected.