Agriculture is the mainstay of the African economy, contributing 20% of the continent's GDP, 60% of its workforce and 20% of exports. Agriculture remains the most important sector of the Beninese economy, contributing around 33% of GDP, 75% of export earnings, 15% of government revenue and employing 70% of the working population. Farmers continue to use chemical products and are increasing the quantities of pesticides. Herbicides are among the most widely used pesticides, with almost 200 in use.Weed science is a scientific discipline that focuses on the study of weeds. These plants can be harmful to crops, gardens, lawns and even natural ecosystems. Weed science aims to understand the biology, ecology and control of weeds, and to develop sustainable methods for managing them.