Effects of integrated weed control on labour organization and economic profitability of farms This paper aims at assessing the performances of four cropping systems prototyped according to the principles of Integrated Weed Management (IWM) agricultural practices. The purpose of the study is to analyse the viability of these IWM cropping systems, focusing on the labor organization at the farm level and on the economic profitability. We compared four variants of IWM cropping systems (S2-S5) with the conventional system (S1) in an experimental farm located in Dijon (France). The methodology combines the empirical results from the field experiments with simulations with a computing program to analyse the working time and the net margin of different systems considered. The data used was derived from the techniques really implemented on the INRA experiment from 2000 to 2006. Regarding the labour feasibility, results showed that the decision rules in IWM induced problems and soil seed bed preparation and cereal sowing. Late wheat sowing for escaping the period of autumn weed emergence delayed those operations in a period with less favourable weather conditions. Mechanical weeding was rather easily inserted in the labour organisation plan. Regarding economic profitability, IWM systems are associated with (i) increased machinery costs, (ii) lower operational costs due to lower pesticide costs, (iii) mean net returns per hectare decreased as compared to the standard system because of lower yield value iv) mean net returns per hour can rise because of better labour organisation.