Occurrence and Distribution of Common Diseases and Pests of U.S. Cannabis: A Survey

Abstract

Hemp and marijuana, both Cannabis sativa L., are revitalized crops to U.S. agricultural and horticultural industries. Hemp (Δ⁹-Tetrahydrocannabinol content <0.3%) was reintroduced in 2014 under a pilot research program and legalized in 2018. Hemp can now be grown in all 50 states. Marijuana (Δ⁹-THC content > 0.3%), though classified as a Schedule I narcotic by the U.S. Drug Enforcement Administration (DEA), is legal in 40 states and the District of Columbia for medical and/or recreational use. Although C. sativa is often promoted as a pest-free crop, multiple diseases and arthropod pests have been identified and confirmed in recent years. There are limited options for control of diseases and pests affecting hemp. A survey of diagnosticians, researchers, and industry leaders conducted in 2021-22 sought to determine the distribution and occurrence of 76 common diseases and pests on C. sativa across the U.S. A total of 148 responses were collected and grouped by U.S. region: Western, Great Plains, North Central, Northeastern, and Southern. Survey results suggest that while some pathogens and pests are widely distributed across the U.S., others occur more frequently in specific regions. This finding may indicate variations in economic importance by region. Results from this survey provide a foundation for regional and national prioritization of research and regulatory activities.

Fungal and mycotoxin contaminants in cannabis and hemp flowers: implications for consumer health and directions for further research

“…In a recent survey of diagnostic professionals in the United States, infection by Fusarium spp. on cannabis or hemp in most areas of the country, except for the Great Plains region ( Munir et al, 2023 ); this is likely due to the low numbers of samples received from this region. Similarly Canadian production areas have reported f Fusarium occurrence on cannabis plants and inflorescences during commercial cultivation ( Punja et al, 2019 , 2021 , 2023 ; Punja, 2021a , b , c ; Punja and Ni, 2022 ).…”

“…A number of Fusarium spp. that have been reported to infect cannabis inflorescences can produce an abundance of mycelial growth and mycotoxins under laboratory conditions ( Gwinn et al, 2022 ; Munir et al, 2023 ). In a recent survey, diseases caused by Fusarium (including Fusarium head blight and Fusarium wilt) were commonly encountered during cannabis and hemp production in the United States ( Munir et al, 2023 ).…”

“…that have been reported to infect cannabis inflorescences can produce an abundance of mycelial growth and mycotoxins under laboratory conditions ( Gwinn et al, 2022 ; Munir et al, 2023 ). In a recent survey, diseases caused by Fusarium (including Fusarium head blight and Fusarium wilt) were commonly encountered during cannabis and hemp production in the United States ( Munir et al, 2023 ). This may have important implications for cannabis worker safety, as exposure to infected cannabis plants has been linked to cutaneous fusariosis ( Altibi et al, 2020 ).…”