Selecting Coriandrum sativum (Apiaceae) varieties to promote conservation biological control of crop pests in south Florida

Coriandrum sativum L. (Apiaceae) is an annual herb that produces numerous flowerheads and is a host plant for aphids. Studies have demonstrated that adding C . sativum to different kinds of cropping systems can enhance biological control of pests in those crops. This study represents a first step towards selecting C . sativum accessions that would perform well as insectary plants in citrus groves. Coriander accessions were grown and evaluated to determine which would grow well and flower quickly in south Florida. Because latitude may affect flowering time, accessions that were tested originated from localities within 10° latitude of the study site (27.418 °N), i.e., India, Pakistan, north Africa. Two of the Indian accessions produced healthy plants that flowered more quickly than the others. Seed from these two accessions were saved, which when sowed produced an open-pollinated (OP) hybrid that grew well in south Florida. A second test was performed to determine if co-sowing the seeds of the quick-flowering OP hybrid coriander with the seeds of a slow-to-flower variety (cilantro) would result in overlapping flowering periods. The flowering periods of the two varieties overlapped by approximately 1 week while the overall flowering period was extended by 35 days relative to planting each variety by itself. The results showed that the coriander and cilantro varieties of C. sativum can be co-sown to ensure an extended flowering period, saving the grower time and effort and providing a better habitat for biological control insects.