Black-Stain Root Disease

Roots show black wood discoloration with eventual decline. This disease spreads by root contact. Remove infected trees. The pathogen (Leptographium wageneri) favors moist conditions and enters through wounds or natural openings. You are most likely to see symptoms during the growing season when conditions shift between wet and warm. On susceptible hosts, the damage can progress quickly if left unchecked.

Favor resistant species. Plant at wide spacing to avoid pre-commercial thinning. Remove infected material promptly and improve growing conditions to limit pathogen spread. Good sanitation, adequate spacing, and proper irrigation practices reduce disease pressure over time.