Progress towards Sclerotinia--Resistant Varieties

Sclerotinia crown and stem rot (SCSR), caused by the fungus Sclerotinia trifoliorum, is one of the most important factors limiting the success of late-summer alfalfa seedings in the region. Infections of S. trifoliorum that progress into the crown of a fall-sown alfalfa plant can kill it during winter or spring green up. Stand losses by the following spring may be insignificant (1-3%) or nearly total, with 95-99% of the stand being dead (and often even rotted away and gone by spring green-up)