Avoid Planting Scotch Pine Near Dwarf Mistletoe-Infected California Pines

摘要

Eight-year-old Scotch pine (Pinus sylvestris) were severely infected by dwarf mistletoe (Arceuthobium occidentale) when planted near infected Digger pine (P. sabiniana) in the foothills of the northern Sierra Nevada, in California. But 6-year-old knobcone x Monterey (P. attenuata x P. radiata) hybrid pines in the same plantation were uninfected. To prevent infection, avoid planting Scotch pines near native California pines bearing dwarf mistletoe.