5.6.9
EFFICACY OF SOME SELECTED FUNGICIDES IN THE PROTECTION OF WINTER OILSEED RAPE AGAINST LEPTOSPHAERIA MACULANS

Z KAROLEWSKI and Z WEBER

Department of Phytopathology, University of Agriculture, ul. Dabrowskiego 159, 60-594 Poznan, Poland

Background and objectives
The vegetation period of winter oilseed rape lasts from 10 to 11 months. Development of the plant and its pathogen, Leptosphaeria maculans, is stopped only during winter. Chemical control of the pathogen has to be done during winter, spring, and summer. An objective of this work was assessment of six selected fungicides in the protection of winter oilseed rape against L. maculans.

Materials and methods
Two cultivars (Bolko and Mar) of winter oilseed rape, three fungicides (Baytan Universal 19,5 OS - a.i. triadimenol, imazalil, fuberidazole; Sibutol 35,9 FS - a.i. bitertanol, fuberidazole, and Zaprawa Oxafun T - a.i. carboxin, thiram) for seed dressing and three fungicides (Alert 375 SC - a.i. flusilazole, carbendazin; Alto 320 SC - a.i. cyproconazole, and Benlate 50 WP - a.i. benomyl) were used. The number of infected plants and degree of infection were evaluated.

Results and conclusions
The efficacy of L. maculans control in the experiment depended on the oilseed rape cultivar, kind of fungicide, and the term of its application. Better results were received with fungicides Alert 375 SC and Alto 320 SC than with Benlate 50 WP. Seed dressing with Sibutol 35,9 FS or Zaprawa Oxafun T partially protected young plants against the pathogen.