MAC39, MAC9, P2 and Budogovsky 9, while resistant rootstocks include M.4, M.7, Ottawa 3 and Novole. Ornamental crab apples and other Malus species appear unaffected, as are most apple cultivars on seedling rootstocks. Symptoms of AUND appear as infected trees reach bearing age. Bud break is often delayed in the spring, and leaves are small and sparse, their color a dull, pale green. Terminal shoot growth is reduced, with shortened internodes.
Infected trees flower heavily and set large numbers of small, highly colored fruit.
Leaf discoloration and leaf drop occurs prematurely in infected trees. Affected trees often produce large numbers of sprouts from the rootstock. Swelling may occur above the graft union. Decline and death is possible, although infection is not always lethal. The virus is present in common broadleaf orchard weeds, such as dandelion, and may be spread from weeds to apple trees by dagger nematodes.