Ohio FG1 and Ohio FG2 both carry the Rps3 gene for resistance to phytophthora rot. Also found in the variety 'Chapman', this gene confers resistance to races 1, 3, 4, 16, and 25, but not to race 7. In tests of tolerance to race 7, Ohio FG1 was rated moderately intolerant and Ohio FG2 highly tolerant. In four years of testing in Ohio, no symptoms of phytophthora rot have been observed on either variety.
Both Ohio FG1 and Ohio FG2 are susceptible to brown stem rot [caused by Phialoiohora gregata (Allington and Chamberlain) W. Gams]. Observations in Michigan and Ohio in 1994 suggested that, when the disease occurs, symptoms of brown stem rot are more severe on Ohio FG1 and Ohio FG2 than on most other varieties. Growers should avoid fields where this disease is known to be a problem, such as fields where soybeans were grown the previous year and brown stem rot symptoms were observed.
Ohio FG2 is susceptible to purple seed stain [caused by Cercospora kikuchii (T. Masu. & Tomoy- asan) and to pod and stem blight [caused by Dianorthe phaseolorum (Cke. & Ell.) Sacc. var. soiae (Lehman) Wehm.]. The reaction of Ohio FG1 to these diseases has not been evaluated.
Assays using Mexican bean beetle [Epilachna varivestis Mulsant] indicated that Ohio FG1 and Ohio FG2 incurred greater loss of leaf area than the variety Williams when attacked by foliarfeeding insects. Ohio FG1 and Ohio FG2 have larger leaves than most grain-type cultivars, and it is not known whether this loss of leaf area would lead to reduced yields. Although economic damage from leaf-feeding insects is rare in Ohio, growers of these new varieties should be prepared to scout fields carefully if leaffeeding insects are a threat.