David M. Nyaga
Abstract: Relationships between plants and their environments are complex and varied. They range from parasitism, mutualism, saprophytism to competition. Technically, it is difficult to assess how harmful or beneficial a relationship may be but it is always possible to describe their effects. Parasitism is one of the harmful associations that have been studied widely. In Kenya the family Loranthaceae (mistletoes) causes considerable deaths of many indigenous, exotic and ornamental trees. This paper presents results of an exploratory survey carried at Egerton University Njoro Campus between SeptemberNovember 2007 to investigate the level of infestation on trees by mistletoe. The specific objectives were to estimate and compare infestation levels on exotic and indigenous tree species. Random stratified sampling with ocular estimation was used. The results indicated that Schinus molle, Fraxinus pennyslvanica and Acacia mearnsii were the most infested. On the other hand Polyscias fulva (Hiern) Herms, Croton megalocarpus and Spathodea campanulata (Seem) were the least infested or were free of infestation. Indigenous species had the least infestation levels when compared to exotic species. We recommend further investigations into the prevalence of the parasite in natural and plantation forests with a view of determining avenues for the containment of the parasite.
Keywords: Words mistletoe, infestation, trees, Egerton, University