Selecting plants to promote conservation biological control of crop pests: a case study with coriander (Coriandrum sativum) in south Florida

Authors: Patt, Joseph

Submitted to: Florida Entomologist
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/31/2025
Publication Date: N/A
Citation: N/A

Interpretive Summary: Coriander, also known as cilantro, can be grown not only as a food crop but also to support beneficial insects in farmland. 'Cilantro' varieties of this herb do not flower for many weeks, so that the plant can produce bunches of the flavorful leaves used for garnishes. 'Coriander' varieties of this herb, on the other hand, flowers soon after sowing to quickly provide savory seeds. The first goal of this study was to screen seeds of coriander varieties from around the world to determine which ones would flower quickly in south Florida citrus groves. The seeds were primarily from India and Pakistan, but some were from Ethiopia, Morocco, and Tunisa. Two of the Indian varieties produced vigorous plants that flowered much sooner than the other varieties. These two coriander varieties produced offspring that grew well in south Florida. The second goal of the study was to determine if sowing seeds from the quick-flowering coriander variety with those of a slow-flowering cilantro variety resulted in an overlap in their flower periods. The results showed an overlap in flowering times when coriander and cilantro were planted together with the overall flowering period being extended by several weeks. These results showed that the two varieties can be sown together to provide an extended flowering period that is longer than if either one was planted by itself. This approach will save farmers time and effort while providing a better result in terms of providing habitat for beneficial insects in farmland.

Technical Abstract: Coriandrum sativum is an annual herb that is not only a culinary crop but also an important insectary plant that can attract and support beneficial insects in agroecosystems. Cilantro varieties of C. sativum have a prolonged juvenile stage and resist flowering for many weeks while coriander varieties flower soon after sowing. The first goal of this study was to screen coriander accessions to determine which ones would grow well and flower quickly in south Florida. Because latitude affects flowering time, most of the accessions, obtained from USDA-North Central Regional Plant Introduction Station, originated within 10º latitude of the study site, primarily from India and Pakistan but also from north Africa. Two of the Indian accessions produced healthy plants that flowered more quickly than the others. These two accessions were then used to produce an open-pollinated hybrid that performed well as an insectary plant in south Florida. The second goal of the study was to determine if co-sowing the seeds from the quick-flowering coriander hybrid with the seeds of a slow-bolting cilantro variety (Santo) would result in overlapping flowering periods. The flowering periods of the two varieties overlapped and the overall flowering period was extended by several weeks relative to planting each variety by itself. This results showed that rather than relay sowing each variety, the two varieties can be co-sown to ensure an extended flowering period, saving the grower time and effort with a better result in terms of providing habitat for beneficial insects.