تاثیر چند قارچکش در مهار گونه های Fusarium عامل زوال درختان سیب

Symptoms of apple trees decline in Semirom apple orchards of Isfahan province were observed as weakness, wilting, decrease in the amount of foliage and suddenly whitening of some branches. After sampling, the infected tissue was cultured on PDA medium containing antibiotics. Fusarium spp. colonies appeared predominately. Morphological and molecular studies using Tef1/tef2 primers showed the existence of two species F. solani and F. oxysporum. In order to evaluate the efficacy of several fungicides on the control of isolated fungi, using in vitro mycelial growth inhibition assay a completely randomized design in laboratory conditions was performed. Tilt (Propiconazole), Eminent (Tetraconazole), Cabrio Duo (Pyraclostrobin+Dimethomorph), Collis (Boscalid+Kresoxim-methyl), Ortiva Top (Azoxystrobin+Difenoconazole), Lamardor (Tebuconazole+Prothioconazole), Uniform (Azoxystrobin+Mefenoxam), Flint (Trifloxystrobin), Stroby (Kresoxim-methyl), Rovral Ts (Iprodione+Carbendazim) and Topsin M (Thiophanate-methyl) fungicides were tested at four concentrations 10, 25, 50, 100 and 200 milligram per liter in three replications. Colony diameter was measured at different concentrations and the average percentage of mycelial growth inhibition at each concentration was calculated. Statistical analysis of experimental data was performed using SAS software. The results on F. solani showed that Tilt fungicide at concentrations of above0 mg/l, eminent and Cabrio Duo fungicide at concentrations of above 100 mg/l, Ortiva Top fungicide at concentrations of above 50 mg/l, Rovral TS fungicide at concentrations of above 25 mg/l and Lamardor fungicide at concentrations of above 10 mg/l showed more than 50% average percentage of growth inhibition, but Collis, Uniform, Flint, Stroby and Topsin M fungicides at the maximum test concentration (200 mg/l) average percentage of growth inhibition less than 50%. Also the results on the F. oxysporum showed that Tilt, Eminent, Ortiva Top, Lamardor and Rovral TS fungicides at concentration of above 10 mg/l, Cabrio Duo fungicide at concentration of above 100 mg/l, Collis fungicide at the maximum test concentration (200 mg/l) have average percentage of growth inhibition more than 50%, but Uniform, Flint, Stroby and Topsin M average percentage of growth inhibition less than 50%. According to the results it seems that Lamardor, Rovral TS, Ortiva Top, Tilt and Eminent fungicides had more impact on mycelial growth inhibition of Fusarium species than other fungicides in laboratory conditions. It is also recommended that fungicides be tested in greenhouse or orchard conditions.