Disease Note.

First Report of Heterodera glycines on Soybean in South Dakota. J. D. Smolik, Plant Science Department, South Dakota State University, Brookings, 57007. J. L. Jones, and D. L. Gallenberg, Plant Science Department, South Dakota State University, Brookings, 57007; and J. P. Gille, Union County Extension Office, Elk Point, 57025. Plant Dis. 80:224. Accepted for publication 21 December 1995. Copyright 1996 The American Phytopathological Society. DOI: 10.1094/PD-80-0224F.

Soybean fields in 12 eastern South Dakota counties were surveyed for the soybean cyst nematode (Heterodera glycines Ichinohe) during the 1995 growing season. The 255 fields included in the survey had a 10- to 15-year history of soybean production (primarily in rotation with corn), and were selected with the aid of local extension service agents. In the initial phase of the survey, H. glycines was detected in a single field of the 23 sampled in Union County, which is located in the extreme southeastern corner of South Dakota. Twenty-two additional fields within 2 to 3 km of the original field were assayed for H. glycines. The nematode was confirmed in 10 (45%) fields. Nematode identification was based on cyst morphology (2), presence of males, and reproduction on soybean in greenhouse studies. Reproduction of the original H. glycines isolate on the race differentials (1) was consistent with the definition of race 3.