This relationship with modern varieties seems less dependable. Fall dormancy ratings provided by the seed industry are given in Table 1. 4. Disease and pest resistance. Variety selection based on yield performance alone is less satisfactory than selections that also consider disease resistance characteristics. Resistance to specific disease-causing pathogens may be the most important attribute in an alfalfa variety.
Pathogens can dramatically reduce yield and persistence of susceptible varieties.
For example, Phytophthora root rot resistance is often very important on soils that are less than well-drained. Below is an explanation of the information found in Table 1. Nearly all alfalfa varieties currently grown in Ohio have resistance to Bacterial Wilt and Fusarium Wilt. The widespread use of these varieties has greatly diminished the significance of these diseases. However, severe losses can still be incurred in stands of susceptible varieties.