Verticicladiella Root Disease of Pinus strobus in New Zealand. C. G. Shaw III, Forest Research Institute, Rotorua, New Zealand. M. Dick, Forest Research Institute, Rotorua, New Zealand. Plant Dis. 64:96-98. Accepted for publication 5 April 1979. This article is in the public domain and not copyrightable. It may be freely reprinted with customary crediting of the source. The American Phytopathological Society, 1980. DOI: 10.1094/PD-64-96.

Verticicladiella sp. was isolated consistently from black stained sapwood of dead and dying in two forests on the North Island of New Zealand. This is the first report of a species of Verticicladiella in New Zealand. The heaviest mortality associated with the fungus was along temporary access roads in the most poorly drained portion of one stand. Microscopic examination of infected sapwood showed hyphae in axial and ray tracheids and ray parenchyma. Verticicladiella sp. was reisolated consistently from inoculated damaged P. strobus roots but not from undamaged roots. Isolates in culture exhibited optimum growth near 20 C, more profuse growth at 25 C than 15 C, and no growth at 30 C. Sporulation occurred at 20 C and was most profuse at 25 C.