Farmers themselves are allowed to manage on-farm variety adaptability trials (VATs), to represent farmer management practices in preference to research management. In this approach, within-trial uniformity and thus the scientific value of VATs will be lost. A study was conducted using rice to ascertain whether representation of farmer management in VATs is necessary and to test an approach that represents farmer management without losing within-trial uniformity and the scientific value of VATs. In the proposed approach, both the representation of farmer management and within-trial uniformity are reasonably assured through implementation of site-specific farmer practices by research personnel. This approach was compared with complete research management using recommended practices in a VAT conducted with five rice varieties in six farmers' fields over two seasons. When farmer management was implemented by research personnel, popular varieties among farmers were judged most adaptable. However, when VATs were managed using recommended practices, popular varieties among farmers were judged least adaptable. This provided direct evidence to show the usefulness of representation of farmer management and the validity and practical feasibility of the proposed approach in managing VATs.