Pinus diseases in the tropics
Brief surveys have been conducted from 1983-87 in many tropical countries, on foliage pathogens in Pinus plantations, research plots, nurseries and natural forests. In addition to visual observations, samples were collected for detailed analysis. The main pathogens studied were the following: Mycosphaerella gibsonii (EPPO A1 quarantine pest), Mycosphaerella pini (EU Annex II/A2), Mycosphaerella dearnessi (EPPO A1 quarantine pest), Sphaeropsis sapinea and various other foliage diseases.
Mycosphaerella gibsonii has been observed on 24 Pinus species, including new host records (P. ayacahuite, P. clausa, P. greggii, P. pseudostrobus, P. rudis). In addition, M. gibsonii is recorded for the first time in the following countries: Bangladesh, Jamaica, Kenya, Madacasgar, Nepal, Papua New Guinea, South Africa, Sri Lanka, Swaziland and Thailand. This suggests that this fungus is much more widely distributed in tropical and subtropical regions than previously thought.
Mycosphaerella pini has been found on 10 Pinus species in 12 countries of Africa, South America, Asia and the Caribbean: Ecuador, India, Jamaica, Kenya, Malawi, Nepal, Philippines, South Africa, Sri Lanka, Tanzania, Zambia, Zimbabwe. These are the first reports of M. pini in Nepal, Philippines, Sri Lanka and Zambia.
Mycosphaerella dearnessii was observed on 4 Pinus species in the USA and Colombia only. It is mostly associated with P. radiata in Colombia, and P. taeda and P. palustris in southern USA.
Sphaeropsis sapinea was observed on 21 Pinus species in 13 tropical countries and appears pantropical but is particularly common in Africa.
The author felt that records of M. gibsonii and M. pini from remote native blue pine (P. wallichiana) forests and M. gibsonii from native Chir pine (P. roxburghii) forests in Nepal suggest that both fungi are endemic to the Himalayan region as well as to Central America and that the low number of records of M. dearnessi suggest that it has apparently failed to spread to other tropical countries despite the presence of potential host plants.
Ivory, M.H. (1994) Records of foliage pathogens of Pinus species in tropical countries.
Plant Pathology, 43 (3), 511-518.