Abstract
Arrangements of an adequate price's information of agricultural products that are cultivated by small farmers constitute a key element to facilitate commercial operations, improving their incomes. Therefore, it is necessary to develop an agile, dynamical and transparent information mechanism, in order to link producers, buyers, technical, and public organizations, between themselves and others. These elements were had in account to implement MERCOSUR Onion's Information Net. The Agricultural Social Program (PSA) and INTA started it in 1998 in San Juan's province (Argentina). Today, there are more of 20 representative of public and private institutions of various South American countries that participate in it. The main aim of the experience was the articulation of an information net-system which linked the agents who participate in producing and marketing the products, in order to have information to permit every actors knowing at all times the situation of the product's markets.