b'But some challenges remain stubborn. Weve tried for years to get resistance to alfalfa weevil or armyworm, Miller says. Conventional breeding hasnt done it yet.The Belowground Battle With better fiber digestibility and Some pests do their damage where growers cant see itin the root zone. Clover root curculio, formore protein, you start with higher example, chews away the bark of roots, reducingquality, so you have a wider harvest water and nutrient uptake and opening the door for secondary infections. window. If weather delays you a few We dont have any varieties with resistance todays, you can still hit dairy quality it, Miller says. But Cornell is working with benefi-cial nematodes, and theyre getting some control. something older varietiesManaging stress is critical.couldnt do.If youve got clover root curculio and then lose irrigation, you can lose the field, Miller says. Keep Don Millerfertility high and stress low, and the plants have a better chance of recovering.Other Breeding FrontiersMiller points to several areas where breeders are pushing boundaries:Autotoxicity: After three or four years, alfalfa leaves enough chemical in the topsoil to sup-press new seedlings. Michigan State University is developing a soil bioassay to tell growers when its safe to replantand breeding for varieties that deposit less toxin. Bloat tolerance: Grazing pure alfalfa carriesrisk but breeding efforts continue alongside management-based solutions. Acid soil and aluminum tolerance: RenewedClover root curculiointerest is coming from the Southeast, where feeding damage onlow pH soils limit production.alfalfa roots reduces water and nutrientClimate Change Geneticsuptake and opens theMiller says drought stress is one of the most limit-plant to secondarying factors in crop production. Thats why hes infections. focusing on varieties that can handle drought, salinity and heat extremes.In New Mexico trials, some alfalfa stood unwa-tered for three months in summer. It looked dead, but it was in drought-induced dormancy, Miller says. Once water came back, it recovered.Salt tolerance in alfalfa is another frontier. Its becoming a bigger breeding target because it ties directly into both climate change resilience and water management issues.Weve germinated seed at half the concentra-tion of seawater, he says. The survivors become breeding material.8/ SEEDWORLD.COMOCTOBER 2025'