Salts of Methyl-2-benzimidazole Carbamate (MBC) and Assessment of Their Potential in Dutch Elm Disease Control

Abstract

Methyl-2-benzimidazole carbamate (MBC) was solubilized by formation of salts (MBC-phosphate, -nitrate, -hydrochloride, -sulfate, and -sodio derivative). All the salts of MBC exhibited greater fungitoxicity towards Ceratocystisulmi than the parent compound and lower phytotoxicity towards elms. MBC-phosphate was root injected into 12 healthy, mature, field-grown white elms (Ulmusamericana L.) and one with severe symptoms of Dutch elm disease. Controls consisted of seven elms injected with distilled water alone. To date, bioassays of trees treated with MBC-phosphate using the root-injection method have demonstrated extremely good distribution throughout the tree at a concentration which, on the basis of laboratory tests, is sufficient to arrest development of C. ulmi. Treated elms could not be successfully inoculated with C. ulmi conidia, whereas control trees could. Recovery of C. ulmi from the diseased elm was greatly reduced after root injection with MBC-phosphate.