Dothistroma Needle Blight of Pinus patula, P. radiata, and P. canariensis in South Africa. J. E. Lundquist, Plant Protection Research Institute, Private Bag X5017, Stellenbosch, 7600 South Africa. C. Roux, Plant Protection Research Institute, Private Bag X5017, Stellenbosch, 7600 South Africa. Plant Dis. 68: 918. Accepted for publication 1 June 1984. Copyright 1984 The American Phytopathological Society. DOI: 10.1094/PD-68-918d.
During routine disease surveys of commercial pine forests in South Africa in the spring of 1982 and 1983, Dothistroma septospora (Dorog.) Morelet (syn. D, pin i Hulb.), the causal agent of Dothistroma needle blight, was found associated with isolated stands of Pinus patula Schiede in Dargle State Forest in Natal and of P. radiata D. Don and P. canariensis C. Smith in Isidenge State Forest in the eastern Cape. Symptomatic trees showed premature defoliation, needle tip dieback, and spotting of the current year's needles. Characteristic red coloration of the needles was associated with P. radiata and P. patula but not with P. canariensis. This is the first report of the disease associated with P. radiata and P. patula in South Africa. It was found only once before in South Africa in 1965 by Christenson, who reported D. septospora from a P, canariensis stand in the eastern Cape but was unable to locate the fungus on subsequent visits to the same stand in 1966 and 1967.