Problèmes de la lutte chimique au Sahara algérien: cas des acridicides

Abstract

In the Sahara Schistocerca gregaria (Forskal 1775), poses enormous economic problems and so far it has not been possible to fight effectively with any methode other than intense chemical spraying. The Algerian Sahara has been the scene of this struggle over locust invasion or during the preventive control. Repeated random applications at a large scale in the oasis during the course of an invasion frequently raise concern and revealed an evident impact on the Saharan environment and inhabitants' health. The effects of certain types of acaricides including organophosphates, organochlorines, cabamates or synthetic pyrethroids on vertebrates and invertebrates is clearly visible during chemical control measures in palmaries, biotope marked with human activity. After a campaign, adverse effects are noticed on all categories of non-targeted organisms including those useful for the natural wildlife of date palms. Furthermore, the phytotoxic action of certain classes of insecticides on the physiology of date palms was noted, impacting on the morphological quality of dates which appear crenellated. In addition, these toxic substances adhere to dates which may be destined for human consumption. The zones subjected to these substances are characterized by sandy soils, with the solum showing extensively wide diameters. As such, polluted streaming water is not retained in the superficial layers and can easily infiltrates into deeper layers. The composition of deep water depends on the physicochemical properties of these waters,