Activity and persistence of I.B.S. fungicides against brown rust of wheat.

Abstract

The effectiveness and persistence of triadimenol, propiconazole and fenpropimorph against brown rust of wheat (caused by Puccinia recondita f.sp. tritici) was compared with that of more recent triazole fungicides (tebuconazole, tetraconazole, cyproconazole and flutriafol) in field studies in Italy. In several field trials carried on cv. Gemini between 1989 and 1992, all the fungicides were found to be very effective, but differed with regard to their persistence. Tebuconazole (as Folicur at 250 g a.i.), cyproconazole (as SAN 619 at 80 or 100 g a.i.) and tetraconazole (as M 14-360 at 125 g a.i.) were the most persistent (25-30 days), followed by flutriafol (as Impact at 125 g a.i.) (20-25 days) and propiconazole (as Tilt 10 EC at 125 a.i.), triadimenol (as Bayfidan EW at 125 a.i.) and fenpropimorph (as Corbel at 795 g a.i.) (18-20 days). It is concluded that longer persistence of tebuconazole, cyproconazole and tetraconazole makes them the most effective tools for the control of brown rust.