There are three or more sources of major gene resistance. There are several races of SCN, but any of the three sources of resistance is effective against the Iowa populations. Sclerotinia stem rot Resistance is polygenic, and there are some varieties with good white mold resistance. Growth characteristics of different varieties also may influence their tendency to be infected. You should make disease resistance a priority if a potentially recurring disease was a problem in 1995 or 1996.
Most diseases do tend to recur due to pathogen buildup.
Resistance is most effective if used in combination with crop rotation and other management practices. Continuous planting of one resistant variety can lead to a breakdown in resistance to some diseases, so there is some risk to overuse of resistance. In the absence of disease, some resistant varieties may not yield quite as well as susceptible varieties, but the difference is usually small, especially when compared to the substantial yield benefit of resistant varieties in the presence of disease. This information subject to a usage policy .