Occurrence of Fusarium subglutinans f.sp. pini in South Africa
Fusarium subglutinans f.sp. pini is the causal agent of pine pitch canker. Symptoms of the disease are characterized by resinous cankers on the main trunk and large branches, and shoot die-back in the upper crown. In 1974, the disease reached epidemic proportions in plantations and seed orchards of Pinus elliottii and P. taeda in the Southern United States. More recently, it has been reported ;from California (in 1987), Japan (1989) and Mexico (1991). Between 1990 and 1992, F. subglutinans f.sp. pini has been observed in South Africa where it caused a serious root disease of pine seedlings. However, the disease has not yet been detected on mature trees in commercial forests. The authors noted that all pine species grown in South Africa (P. patula, P. elliottii and P. radiata) are exotic species. As the recent appearance of pitch canker in South Africa is of considerable concern, the authors have studied the susceptibility of P. patula, P. elliottii and P. radiata to F. subglutinans f.sp. pini. One-year-old seedlings of the three pine species were inoculated with eight isolates of the fungus. In all cases canker development and shoot mortality were obtained. Disease development was significantly more severe on P. patula and P. radiata than on P. elliottii.
Sources
Viljoen, A.; Wingfield, M.J.; Kemp, G.H.J.; Marasas, W.F.O. (1995) Susceptibility of pines in South Africa to the pitch canker fungus Fusarium subglutinans f.sp. pini.
Plant Pathology, 44(5), 877-882