CONTROL OF SNOW MOLD (MONOGRAPHELLA NIVALIS) IN LAWN BY AZOXYSTROBIN

The impact of different fungicides (azoxystrobin, azoxystrobin+flutriafol, chlorothalonil and propiconazole) on occurrence and severity of pink snow mold (Monographella nivalis (Schaffnit)E. Müller var. nivalis) on lawn were investigated in trials at the Grassland Research Station at Zubří during 1999 – 2002. Azoxystrobin (Amistar) at rates of 1 and 2•L ha^-1 and azoxystrobin+flutriafol (Amistar Gem) at 1.5 and 3 L•ha^-1 gave the best control in a grass sward composed of three different varieties of red fescue (Festuca rubra L.), Kentucky bluegrass (Poa pratensis L.) and creeping bentgrass (Agrostis stolonifera L.) in the winter 1999/2000. The efficacy of both chemicals differed significantly from that of chlorothalonil (Bravo 500) and from the untreated control. The effect of Amistar and Bravo could not be evaluated in 2001 because of the very low incidence of snow mold. In 2002 and on the same grass sward, azoxystrobin (Amistar) at the rates of 0.8 and 2•L ha^-1 gave significantly better disease control, compared to propiconazole (Tilt 250 EC) or the untreated plots. The best green color in winter was observed in all treated plots, and the lowest number of plants of annual bluegrass (Poa annua L.) was recorded in plots treated with azoxystrobin in 2001.