Ecosystems of Innovation Support Services appear as critical tools to accelerate innovations in agriculture and contribute to responding to the Grand Challenges for achieving the SDGs. Deepening our understanding of the drivers and models of service ecosystems' emergence is needed to improve their efficiency. Our research builds on theoretical frameworks of service ecosystems, alignment, and emergence in different activity sectors. Considering the specificities of innovation in the agricultural sector, we propose new insights on service ecosystems' emergence through the evolving role of the hub organization along the innovation journey. We took an abductive approach anchored in over 5 years of case study data regarding innovative labelling of organic farming in Sub-Saharan Africa (technical, social, and organizational innovations mobilizing several innovation support services). We identified three phases of emergence with several necessary preconditions, two different emergence models related to the nature of the hub organisation and two key drivers conditioning emergence.