Selection of appropriate varieties is a critical aspect of an IPM program. Of special importance is the disease, insect, and nematode resistance package of a variety, but other factors are important as well. Often, there are few other cost-effective strategies available, especially for root diseases and nematodes. Varieties should be selected for maximum yield, high level of pest resistance within the appropriate fall dormancy classification for a given area.
| Fall Dormancy | Bacterial Wilt | Verticilium Wilt | Fusarium Wilt | Anthracnose Race 1 | Phytophthora Root Rot | Spotted Alfalfa Aphid | Pea Aphid | Blue Alfalfa Aphid | Stem Nematode | Southern Root Knot Nematode | Northern Root Knot Nematode | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Zone | FD | BW | VW | FW | AnTh | PRR | SAA | PA | BAA | StN | SRKN | NRKN |
| Intermountain | 3–5 | HR | HR | HR | HR | HR | R | R | R | HR | R | R |
| Sacramento | 4–8 | R | R | HR | HR | HR | HR | HR | HR | HR | R | R |
| San Joaquin Valley | 7–9 | R | R | HR | HR | HR | HR | HR | HR | HR | HR | HR |
| Coastal | 5–7 | HR | HR | HR | HR | HR | MR | HR | HR | HR | HR | HR |
| High Desert | 4–8 | HR | HR | HR | HR | HR | R | R | HR | HR | HR | HR |
| Low Desert | 8–11 | MR | LR | HR | R | HR | HR | HR | HR | R | HR | HR |
| Fall Dormancy Rating: Varieties are rated 2–11, with 2 being most dormant during fall period and 11 being least dormant or most winter active in standardized field tests. |
| Resistance abbreviations: Ratings are based upon the percentage plants in a cultivar population which are resistant in standardized tests: HR=Highly resistant ( >51% of population), R=Resistant (31–50% population), MR= Moderately Resistant (15–30% of population), LR= Low Resistance (6–14% of population) |
Consult relevant publications for more information on alfalfa varieties:
- For a complete discussion on alfalfa varieties, see Irrigated Alfalfa Management for Mediterranean and Desert Zones, UC ANR Publication 3512.
- For currently available resistant varieties, see the list of alfalfa varieties provided by the National Alfalfa & Forage Alliance website.
- For current variety performance data for California, see University of California Alfalfa and Forages website.