In vitro and In vivo Efficacy of some Fungicides against Phytophthora nicotianae

This study was conducted in order to determine the in vitro and in vivo efficacy of some chemicals against Phytophthora nicotianae, which is one among the Phytophthora spp. that are responsible for tomato root and crown rot disease. We tested various active substances against this disease pathogen. In the experiment, varied concentrations of "metalaxyl 35%", "fludioxonil 25 g/L + metalaxyl-M 10 g/L", "ametoctradin 300 g/L + dimethomorph 225 g/L", "hymexazol 360 g/L" and "tolclofos methyl 30% + thiram 30%" active substances were used. In in vitro studies, EC50/EC90 values that inhibited sporangium formation and mycelium growth of P. nicotianae was calculated separately for each active substance. In pot experiments, application doses of active substances were applied to tomato seedlings and the active substance that prevents the disease best was determined. As a result of in vitro studies, "metalaxyl 35%" provided the lowest EC50/EC90 concentration that prevents mycelium growth by 50% and 90%. The lowest EC50/EC90 concentration values that decreased the sporangium formation by 50% and 90% were obtained from "ametoctradin 300 g/L + dimethomorph 225 g/L." In pot the experiment, "Fludioxonil 25 g/L + metalaxyl-M 10 g/L" exhibited the highest efficacy against P. nicotianae. (C) 2018 Friends Science Publishers