Can floral field margins improve pollination and seed production in coriander Coriandrum sativum L. (Apiaceae)?

To understand how habitat management influences agricultural production, the present study investigated whether the vicinity of mixed (six annual herbaceous species) or monospecific (Diplotaxis tenuifolia) floral margins can improve seed production in coriander. Potted coriander plants under field conditions were used to test: (i) the contribution of insect pollination (open versus bagged umbels) to coriander seed production and (ii) the contribution of floral margins (mixed or monospecific) to pollinator visitation to coriander. Although coriander showed the capacity to self-pollinate, bagged umbels (no insect pollination) produced significantly less seeds than open-pollinated coriander umbels. In the vicinity of floral margins (mixed or monospecific), coriander plants were more frequently visited by pollinators than control plants (no margins), which consequently improved seed production and quality (seed weight and germination rate). Finally, the present study showed that the presence of both mixed and monospecific margins can improve the production of coriander seeds by more than 220% and, in addition, conserve local pollinators within agro-ecosystems.