Abstract:

The control of A. alternata, causes significant losses in forest trees, vegetables and fruits, with registered fungicides cannot provide the desired effect. In this study, active ingredients of new generation fungicides (Phosphorus acid (D*), Thiophanate methyl + Tetraconazole (Y*), Pyraclastrobin + Fluxapyroxad (P*), Metrafenone (V*), Azoxystrobin + Propiconazole (As), Azoxystrobin + Cyproconazole) (Ar)) and various combinations there of were tested. In the study, the doses of all fungicides in field conditions (mg L-1) were used and each application was made with four replications. A. alternata grown on pure Potato Dextrose Agar (PDA) medium. Mycelial discs (9 mm diameter) obtained from isolates were immersed in the relevant fungicide solutions for 45 seconds and transferred to PDA medium. In the study, mycelial growth diameters of the isolates were measured with an interval of two days, and at the end of the experiment, the % inhibition rates of the isolates against fungicides were calculated. As a result of the 18-day development of A. alternata, the most effective fungicides with mycelial inhibition rate were P* with 90.6%, 88%, respectively. Ar* with 5, As with 84.8%, Y* with 71.8%, the least effective fungicides were V* with 7.2% and D* with 37.4%. It is hoped that fungicides, which are found to be effective in the fight against the agent in vitro, can also be effective in field conditions. In addition, the mixture of fungicides with P* and Ar* active substances was compared with the single application of these fungicides, and the effectiveness of the fungicide combinations was discussed. The fact that these active substances are not registered against A. alternata and the efficacy of alternative fungicides is not known, the chemical control of the pathogen, which has a wide host range and can infect different forest and fruit trees and vegetable crops, has been emphasized.