Technical Abstract: Armillaria Root Rot (ARR) is second only to Peach tree short life (PTSL) as a cause of premature peach tree mortality in southeastern US peach production areas. Two species are of importance, A. mellea and A. tabescens, though the latter appears to be more common. Armillaria attacks the root system of a wide variety of tree species and can persist for years in the soil even in the absence of a host. Most peach seedling rootstocks are very susceptible. Above ground symptoms are typical of a stress pathogen. Close examination will reveal a distinctive white mycelial mat beneath the bark of roots. Control of ARR is extremely difficult once established in an orchard. Pre-plant inoculum reduction, rootstock selection, sanitation and chemical control are all important components of a management program.