Parasitism of host trees by the Loranthaceae in the region of Douala (Cameroon)

Abstract

The Loranthaceae constitute the most important parasite plants that cause variable damages: morphological, technological, ecological and socio- economic. These numerous and damaging effects make some parasitic angiosperms true agronomic threats, especially in developing countries. The Loranthaceae is represented in Cameroon by 26 species gathered into 7 genus. The study area includes four sites: a traditional plantation of Cola nitida situated at Penja (70 km Nord of Douala), the main road to Douala airport, one quarter (Logbessou) and Makondo village (80 km East of Douala) in an orchard dominated by Citrus. A total of 2643 individuals of DBH (diameter at breast height) greater or equal to 5 cm were inventoried. 637 individuals were parasitized. Eight known species were identified. Phragmanthera capitata is more frequent and more abundant (76.14%). The infested host trees belong to 16 species gathered into 12 genus and 10 families. The most parasitized host family is Sterculiaceae. The most sensitive host species to the parasitism of Loranthaceae is P. americana (21.51%), followed by C. nitida (17.27%) and Terminalia mantaly (13.65%). Lauraceae is infested by 7 Loranthaceae out of 8 parasites investigated. The consequences of the parasitism of the Loranthaceae demonstrate the need for establishing comprehensive ecosystem management programs.

Key words: Host trees, inventory, Loranthaceae, parasites plants.