PROTECTIVE EFFECT OF ACIBENZOLARSMETHYL ON FIREBLIGHT SEVERITY IN QUINCE AND CHARACTERIZATION OF THE ERWINIA AMYLOVORA STRAINS INVOLVED
O.M. Balajoo, M. Kesahavarzi, A. Zahabi, Y.R. Danesh, R. Haghjuyan
Quince (Cydonia oblonga), a plant of economic importance in Iran, has been destroyed in many locations due to its high susceptibility to fireblight caused by Erwinia amylovora. In this investigation, the protective effects of Bion (active ingredient acibenzolar-s-methyl) against quince fireblight was studied. The experiments were conducted on cv. Isfahan in both glasshouse and screenhouse condition during years 2009-2010. The inoculum comprised a mixture of eight local E. amylovora strains collected from distant provinces of Iran. The plants were sprayed with Bion (100 and 200 mg/l) three times at 4 days interval and inoculated with E. amylovora after 4 days. Control plants were treated with streptomycin and distilled water before inoculation. Results showed that 200 mg/l Bion reduced shoot blight severity up to 71% in 1- and 2-year-old plants in both glasshouse and screenhouse conditions which was comparable to streptomycin. Although Bion caused some phytotoxicity in 1-year-old seedlings, no phytotoxic effects was observed in 2-year-old plants in either conditions.