Use of Systemic Fungicides Metalaxyl and Fosetyl-Al for Control of Sorghum Downy Mildew in Corn and Sorghum in South Texas. I: Seed Treatment. G. N. Odvody, Assistant Professor, Texas A&M Research and Extension Center, Route 2, Box 589, Corpus Christi 78410. R. A. Frederiksen, Professor, Plant Sciences Department, Texas A&M University, College Station 77843. Plant Dis. 68:604-607. Accepted for publication 1 February 1984. Copyright 1984 The American Phytopathological Society. DOI: 10.1094/PD-68-604.

Metalaxyl gave nearly 100% control of sorghum downy mildew (Peronosclerospora sorghi) in corn (Zea mays) and sorghum (Sorghum bicolor) at seed treatment rates as low as 0.05 g a.i./kg. Stands of corn and sorghum were reduced at metalaxyl seed treatment rates higher than 1 g a.i./kg. Fosetyl-Al gave 91–99% control of sorghum downy mildew in sorghum at seed treatment rates of 5 and 10 g a.i./kg.