In 1995 the varieties in se quence from Golden Harvest X194 down to Pioneer 9171 were in the top- yield group. In 1995 the varieties in s equence from Public Leslie down to Public Bell were in the top- yield group. In 1995 the varieties in sequence from Stine 2660 down to Midwest Genetics G2955 were in the top- yield group. There were no significant differences among varie ties for 1993-95. These recommendations are based on data and information obtained from the South Dakota Crop Performance Testing Program and other regional nurseries maintained by land-grant colleges in the Midwest.
Variety performance is dependent on genetics and environment.
Environmental factors such as temperature, moisture, plant pests, soil fertility, soil type, and the farmer's management practices influence variety performance. Note that the performance of recommended varieties in response to environmental conditions is generally better than the performance of other variet ies. The disease can be controlled or managed partially through the use of resistant varieties. However, the resistan ce to Phytophthora root rot is fungus-race specific. This means that resistance to one race does not necessarily give resistance to other races of this disease.