<pre><span lang="EN-US">The Gharb area upstream of the Merja Zerga lagoon, also called the Ramsar Wetland, is a vital area with high agricultural activities, which increase the risk of contamination and pollution of air, water and soil, as well as endanger the ecological system of the area. The first survey has targeted 100 farm wells and has covered a surface of 555 ha, and the second one has targeted 71 pesticide resellers, have revealed the great uses of pesticides (13.6 kg/ha). The data collected is helping to evaluate, by using the indicator called the Treatment Frequency Indicator (TFI), the pressure of pesticides on the environment. As a methodology, we have adopted the calculation of a pressure indicator for the use of TFI pesticides using a platform called OLYMPE, by dividing the dose applied by the user over the recommended or prescribed dose on the product, the input data is collected during field surveys. The results of the survey show that the banana is the crop that undergoes the phytosanitary treatment, registering a TFI of 38. In term of the total consumption of pesticides identified, the orange tree comes at the first place ahead of other crops practised in the study area.</span></pre>