Abstrakt

First Survey of Agricultural Pesticides Used for Crops in Ichkeul Lake-Bizerte Lagoon Watershed (Tunisia)

Salem FB,Olfa Ben Said, Olfa Ben Said, Robert Duran, Olivier Grunberger

Indiscriminate use of pesticides in the modern agricultural practices leads to the contamination of soils, surface and ground waters. The types of pesticides used in the agricultural watershed surrounding the complex Ichkeul Lake-Bizerte lagoon from Tunisia were identified and their quantity estimated. The survey of farmers and dealers of pesticides showed that the most commonly used active ingredients are iodosulfuron (2014 kg), mesosulfuron (1218 kg), 2.4D (4618 kg), glyphosate (2886 kg) and fenoxaprop (5300 kg) as herbicidal active ingredient; tebuconazole (9260 kg) and epoxiconazole (17168 kg) as a fungicide; and deltamethrin (341 kg), as insecticide. Herbicides are used twice a year (pre- and post-emergence), treatment with fungicides is a result of rust attacks, insecticides are applied against insects such as aphids, for example. The percentages of active ingredient were determined to establish a ranking according to the physical-chemical parameters of each active ingredient (solubility, DT50 and KOC). Next, a theoretical estimation of the amount of each active ingredient was determined. Crops agricultural basin of Ichkeul Lake and Bizerta lagoon are important users of herbicides, fungicides and insecticides while vegetable crops use large amounts of insecticides and herbicides.