SENSITIVITY OF BARLEY POWDERY MILDEW (ERYSIPHE-GRAMINIS F SP HORDEI) POPULATIONS AGAINST SOME FUNGICIDAL SUBSTANCES IN CENTRAL-EUROPE

In 1993 in middle Europe (Slovakia, Hungary, Czechia and Austria), the sensitivity of barley powdery mildew populations (Erysiphe graminis f . sp. bordei) against the fungicidal substances triadimenol, tebuconaz ole, flutriafol, propiconazole and fenpropimorph was determined. A dec reased sensitivity of the pathogen against all substances of the triaz ole group was found. Of the preparations investigated, tebuconazole an d propiconazole are considered as the most effective ones. On the othe r hand, triadimenol and flutriafol had little effect. In comparison wi th the previous year, we can state that there was an increase of the p athogen sensitivity against triazole substances due to an increased he terogeneity of the pathogen populations. The sensitivity of the barley powdery mildew populations against fenpropimorph was on the level of sensitive standard isolates. However, the presence of isolates with de creased sensitivity against the morpholine substances was observed.