The project aims at addressing the urgent transition of zero herbicide in viticulture. This transition leads to increase the number of mechanical weeding over the row and inter-row (grassing management, tillage) which results in a higher consumption of fossil fuel and more working time. In order to prevent these issues, one of the solutions is to combine weeding over the row and inter-row in a single pass. The implementation of such practices requires a high precision. They are difficult to implement with the tools currently available on the farms. When these practices are possible, the tractor driver's concentration and dexterity are so much in demand that it is difficult to carry out this work over long periods. In this context, tractor autosteering as a retrofit (second market solution adapted to current machinery) is a particularly interesting short-term solution. Tractor autosteering systems exist in arable crops but the cost of the solutions is not compatible with the investment capacities of most vinegrowers. Recently, several low-cost open source solutions for auto steering tractors have emerged, but they have not yet been tested or combined (TRL 4). Therefore, the project aims at evaluating these solutions and lifting the interoperability locks to combine best possible open source and low cost solution to prototype a relevant auto steering system for viticulture sector (TRL 7). The project is organised in three main Work Packages (WP). The first WP is aimed at acquiring field references with commercial autosteering system to demonstrate the advantage in working time, ease of implementation and efficiency for mechanical weeding as a substitution to chemical weeding to growers. The second WP is fully dedicated to the design and tests of a low-cost open-source autosteering solution. The last WP consists of creating and leading experimental workshops of self-construct open source autosteering solution with groups of growers and advisors. The prototype of the solution will be distributed under an open license in order to guarantee the widest possible distribution and access. The deployment will be promoted through demonstrations and self-co-construction workshops. The gains for users are estimated at 5-10,000€ per year for an average operation (estimated gain when compared with conventional mechanical weeding, taking into account fuel and labour costs and yield losses). The solution developed will enable winegrowers to reduce their use of herbicides while remaining competitive. In France in 2016, more than 80% of the viticulture area was partially or totally managed with chemical herbicides. The development of a low cost auto steering prototype able to retrofit on vineyard tractor based on open-source solutions is, in our opinion, a major step forward in enabling viticulture sector towards zero-herbicide transition. The prototype in the form of an assembled open-source brick solutions whose functionality, robustness and operability will have been tested and proven in the field, will provide winegrowers with an accessible and acceptable solution to achieve optimal mechanical weeding. The auto steering solution developed will also allow winegrowers to use it for other cultural operations. The positioning of the project aims to provide short term solutions to professionals in order to anticipate and facilitate the zero herbicide transition of an entire agricultural production sector. With a strong scientific expertise in precision agriculture the DeMo team of UMR ITAP (Institut Agro - INRAE) wishes to investigate this issue in collaboration with the French vine and wine institute (IFV) by proposing the design and testing of a proof-of-concept prototype likely to meet the specific challenge of zero herbicide transition, especially for small farms. While the DeMo team will be more involved in the development of the prototype, IFV will be in charge of field experiments and in dissemination towards growers and advisors.