Nematodes and Cannabis sativa secondary metabolites

Inflorescences, leaves, and roots of Cannabis sativa contain a wealth of secondary metabolites that are bioactive and have potential as sources of biopesticides (Andre et al., 2016). Cultivars of medicinal C. sativa, CBD-dominant and THC-dominant chemotypes, respectively, are cultivated primarily for the medicinal cannabinoids in the inflorescences (approximately 20% by weight); inflorescences also contain terpenoids and flavonoids but at lower concentrations. Leaves contain less than 10% of the cannabinoids and terpenoids in inflorescences but have higher concentrations of flavonoids (Jin et al., 2020). In general, extracts from inflorescences had greater bioactivity against entomopathogenic nematodes than those from leaves or stems. Extracts of leaves from one THC-dominant chemotype and one CBD-dominant chemotype were attractive to Steinernema feltiae and S. carpocapsae, respectively, whereas extracts from another THCdominant chemotype and another CBD-dominant chemotype were weak repellents to S. carpocapsae (Laznik et al., 2020) . Sterols and triterpenes are the primary components of stem barks and roots (Jin et al., 2020), but other compounds such as aliphatics (Kornpointner et al., 2021), amides (Yamamoto et al., 1991), and cannabinoids (Gul et al., 2018) have also been isolated from roots (Fig. 3). Numerous root compounds impact nematode behavior and development and may influence many of the host-nematode interactions described above.