LAUSR

Abstract Grapevine can be severely affected by phytoplasmas and there is no effective control strategy for management of these diseases. A technique to reduce the number of infected plants could thus arise from the stimulant of plant defence systems to induce recovery. In this order, two components (T1: propamocarb/fosetyl 530:310 g/l and T2: hymexazol) were sprayed with 4/000 concentration on the canopy of symptomatic grapevines (cv. Bidaneh Sefid) infected by phytoplasma in Qazvin and Lorestan provinces (Iran). Treatments consisted of monthly sprays in spring-2016 and 2017 (two applications) in symptomatic plants. Treated plants in 2016 showed any symptoms in next year and treatment repetition were performed in 2017, in same vineyards with different symptomatic plants. Nested PCR analysis of DNA samples extracted from recovered plants failed to detect phytoplasma infection. The results of this study show these resistance inducers could promote host defence in treated phytoplasma infected plants and could be useful for control of grapevine phytoplasma diseases in Iran.