Diplodia pinea the cause of a disease of hard Pines.
This paper deals with the taxonomy of Diplodia pinea (Desm.) Kickx (Sphaeropsis ellisii Sacc.), its hosts and distribution, and the pathological effects of the fungus in the natural and artificial infection of hard Pines. D. pinea is widely distributed in the United States and has also been reported in various countries lying between the latitudes 30 and 50 degrees north and south of the equator in both hemispheres. In the United States the exotic Pines. Pinus nigra, P. sylvestris, and P. mugo var. mughus are most commonly attacked, but the fungus also occurs occasionally on 8 other species of hard Pine. Although no extensive injury has been caused by D. pinea in forest plantations, its presence may be of considerable importance to ornamental trees which it weakens by killing back the growth of successive seasons. Inoculation tests indicate that, while the fungus is capable of infecting healthy, actively-growing buds and leaves, infection will take place more readily through wounds. KEYWORDS: Pinus mugo var. mughus \ Pinus nigra \ disease \ Pinus sylvestris disease