Investigation of the effectiveness of some fungicides against malsecco disease [Phoma tracheiphila (Petri) kanc. & ghik.]

In this study, 14 different concentrations of 12 fungicides, one licensed were tested to supress radial growth of P. tracheiphila mycel in vitro condition. 5.0 ppm and above concentrations of Cyprodinil (375g/Kg) + Fludioxonil (250g/Kg) combination was found to be the most effective on radial growth inhibition. Fluxapyroxad (75g/L) + Difenoconazole (50g/L) combination was the second effective fungicides to inhibit the radial mycel growth at 100ppm and above concentrations. EC50 values of these fungicides were calculated respectively as 0.124 and 1.228 ppm. Fungicides with active substances such as Azoxystrobin, Dithianon and Pyraclostrobin did not show any significant effect in preventing mycelial development of P. tracheiphila. In greenhouse trials, the normal doses of Cyprodinil (375 g / kg) + Fludioxonil (250 g / kg) and Fluxapyroxad (75 g / L) + Difenoconazole (50 g / L) fungicide have not been very effective in preventing disease severity. However, when using twice the application dose, the disease was prevented at 62.6% and 45.3%, respectively, and the licensed fungicide copper hydroxide prevented the disease at most 9.8%.