Phytophthora lateralis on Port-Orford-cedar.

Abstract

Results from annual surveys of the destructive Phytophthora root disease of Port-Orford-cedar (Chamaecyparis lawsoniana (A. Murr.) Parl.) show that the disease is gradually spreading and intensifying within the natural range of Port-Orford-cedar. The disease became established on native trees in the early 1950's in the vicinity of Coos Bay, Oreg., and during its initial buildup invaded most of the low-lying area between Tenmile Lake and Port Orford. Since 1955 its progress, although less spectacular, has been characterized by gradual, steady encroachment into new areas.

Citation

Hunt, John. 1959. Phytophthora lateralis on Port-Orford-cedar. PNW Old Series Research Notes No. 172, p. 1-6