Suppression of Dollar Spot Caused by Sclerotinia homoeocarpa on Creeping Bentgrass (Agrostis palustris Huds.) after Applying Tebuconazole, Chlorothalonil and Their Mixture

Young-Sun Kim1   Hye-Jung Lim2   Suon-Kyu Ham3   Kyu-Seung Lee4   Geung-Joo Lee1,*   

1Department of Horticultural Science, Chungnam National University
2Taejun Agrotech Co. Ltd.
3Daejung-golf Engineering Co. Ltd.
4Department of Bio-Environmental Chemistry, Chungnam National University

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.