Abstract
This study was conducted to evaluate the control efficacy of dollar spot on creeping bentgrass after applying various amounts of tebuconazole, chlorothalonil and mixture of tebuconazole and chlorothalonil (tebuconazole+chlorothalonil). In effect of three fungicides on suppression against Sclerotinia homoeocarpa, tebuconazole and tebuconazole+chlorothalonil were found to inhibit more than 98% fungus growth on medium and 70% in chlorothalonil treatment. The control efficacy of tebuconazole at different rates of 31.25, 62.5, and 125 a.i. mg m-2 on creeping bentgrass showed more than 80%. Application of tebuconazole (125.0 a.i. mg m-2), tebuconazole+chlorothalonil (125.0 a.i. mg m-2+135.9 a.i. mg m-2) and chlorothalonil (135.9 a.i. mg m-2) were suppressed 96%, 80%, 70% for the dollar spot severity, respectively. Correlation between application amount of fungicides and control efficacy of dollar spot was significantly positive, and suggested amount of tebuconazole, tebuconazole+chlorothalonil and chlorothalonil that might suppress more than 80% of dollar spot were calculated to 29.6, 132.2+142.8, and 157.0 a.i. mg m-2, respectively.
Figures & Tables
Fig. 1. Inhibition rate of three fungicides such as tebuconazole (T), chlorothalonil (C), tebuconazole+chlorothalonil (TC) against S. homoeocarpa.