Published data containing fungicide concentrations that control 50% (IC50) of a given fungus were analyzed. In the analysis we considered: (i) the IC50 determined in vitro and in vivo for a given fungicide and for a specific fungus; (ii) the concentration (g/ha) of active ingredient for the fungicide indicated to control a specific disease in the field; (iii) water volume of 120/L used in the spray; (iv) the fungicide a.i. concentration (mg/L) in 120 L volume; (v) and the ratio of the concentration used in the field with that determined in the laboratory. The analysis were performed by using IC50 data for DMIs, QoIs, a carbamate and a benzimidazol against the following fungi Bipolaris sorokiniana, Drechslera tritici-repentis, D. siccans, Fusarium graminearum, Puccinia triticina, Exserohilum turcicum, Phakopsora pachyrhizi and Corynespora cassiicola. The fungicide concentrations sprayed in the field were 33.9 (D. siccans and trifloxystrobin) to 500,000.0 (E. turcicum and iprodione) times higher than that determined in the laboratory. It was concluded that the IC50 was not related to the concentration used in the field and therefore should be used to compare the power among fungicides and to monitor the fungal sensitivity shift towards fungicides
Inhibitory concentration; fungitoxicity; fungicide sensitivity