Pests and Diseases and the Main Control Strategies

Olive tree and its products can be damaged by the presence of numerous pest insects (phytophagous invertebrates). A large group of those phytophagous invertebrates’ species that afflict olive trees is composed of polyphagous species, and the other group made up of monophagous or oligophagous species. This phytosanitary problem of the olive tree constitutes the main obstacle to the productivity of olive growing. As is the case in all countries of the Mediterranean basin due to the big similarity in climatic conditions, the most important and harmful pests that afflict olive trees in Morocco are olive moth (Prays oleae), the olive fly (Bactrocera oleae), the olive psyllid (Euphyllura olivina), and the black cochineal (Saissetia oleae). In addition to these pests, microorganisms are also involved in attacking Moroccan olive trees. The main fungi identified are Fusicladium oleagineum, responsible for peacock eye; Verticillium dahliae, the causative agent of verticilliosis; and Fumago salicina and Capnodium oleaginum, involved in the appearance sooty mold. Among the bacteria involved, Pseudomonas savastanoi pv. savastanoi has been identified as responsible for tuberculosis in olive trees, characterized by the presence of tubers on the branches and stems, as well as Xylella fastidiosa, provoking olive quick decline syndrome. Mostly, pesticides are used to protect the olive harvest from pests and diseases. However, the worrying issue is the negative effects of pesticides on the environment, human health, and product quality. So among the tools available for the management of olive pests and diseases, certain biological practices make it possible to limit the spread of a specific type of disease in crops and new management systems such as integrated production and organic farming.