Study of potential resistance inducers to control of witches’ broomdisease of lime

Witches broom diseases of lime (WBDL) has been considered as one of the most economically devastatingdisease of Mexican lime in southern Iran with limit information on management and no available cure.Resistance inducer compounds are able to induce plant defense system against many different pathogens. Inthis study effects of different chemical inducers on WBDL were investigated in greenhouse and fieldconditions. Results revealed that resistance inducer components including ۳۱% Phosetyl-Al plus ۵۳%propamocarb, Hymexazol ۷۰% and, individually, were effectual in control of WBDL disease developmentafter two applications per year. Ascorbic acid (AA), salicylic acid (SA), Aliette, NanoSilver andSTARNER also showed transient effect against WBDL after three or four applications per year. Thetreatments ۳۱% Phosetyl-Al plus ۵۳% propamocarb (Privicore EnergyTM) ۴/۰۰۰, Hymexazol ۷۰% (۲/۰۰۰)and NORDOX (۰.۵/۰۰۰) decreased the symptom progress of ‘Candidatus Phytoplasma aurantifolia’, thecausative agent of WBDL in plant and decrease WBDL disease severity by approximately ۱۷ to ۴۰%compared with the control (non-treated) in greenhouse condition and ۲۰-۲۵% in garden. These resistanceinducer components also exhibited positive effect on WBDL disease severity, fruit yield and quality in fieldcondition. Altogether, the results of this study indicate some promising sign of induced resistance forsuppress the severity of the disease in WBDL infected orchards

Keywords:

induced resistance , WBDL , Mexican lime , greenhouse , field.