Apple latent viruses
Disease
Apple latent viruses
Apple chlorotic leaf spot virus (ACLSV) Apple stem grooving virus (ASGV) Apple stem pitting virus (ASPV)
Distribution: Common to all fruit-growing regions in eastern North America.
Latent viruses are viruses that survive in their host without causing symptoms. These viruses are transmitted when a virus-infected scion is grafted onto a susceptible rootstock. There are number of latent viruses that affect apple, but these three are the most common. They may occur together, in pairs, or singly. Affected trees begin to show a general decline 1–2 years after grafting. Familiar symptoms associated with the specific viruses are: ACLSV, chlorotic leaf spots, leaf distortion, or leaf stunting (A); ASGV, chlorotic leaf spots, stem grooving and pitting, union necrosis, and swelling above the graft union (B); ASPV, pitting and grooving, epinasty and decline (C).