Diseases of Cannabis sativa Caused by Diverse Fusarium Species

Abstract

The potential of species of Fusarium to cause significant economic losses in Cannabis sativa due to plant diseases and mycotoxin residues is the subject of this review. Sixteen species of Fusarium, reported as associated with cannabis production, are classified in six species complexes: Fusarium oxysporum, F. solani, F. incarnatum-equiseti, F. sambucinum, F. tricinctum, and F. fujikuroi. Taxonomy in this genus is the subject of debate, and removal of species in the F. solani Species Complex to the genus, Neocosmospora, has been proposed. Many species associated with C. sativa are also opportunistic pathogens of humans and animals. Species of Fusarium produce a myriad of mycotoxins, including at least three (deoxynivalenol, zearalenone, and fumonisin B) deemed the most important mycotoxins in human and animal foods. These chemicals vary from the very simple chemicals (moniliformin and butanolide) to the structurally complex depsipeptides (beauvericin and enniatin B) and trichothecenes (deoxynivalenol and its acetylated derivatives, diacetoxyscirpenol, and T-2-toxin). The robust strategies for disease management (e.g., exclusion of the pathogen, control of environment, and host resistance) are in development for this new crop and have primarily relied on management systems for other crops. Biopesticides have been labeled for use on C. sativa; however, few efficacy trials have been performed. Host resistance to these pathogens and transmission are also understudied. The new markets for C. sativa and its derivative products require knowledge for control of these important fungal diseases to provide safe products for human consumption.

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

“… a Pathogens described in Gwinn et al (2022) . b F. avenaceum was recently described in hemp ( Smith et al, 2023 ).…”

Towards dsRNA‐integrated protection of medical Cannabis crops: considering human safety, recent‐ and developing RNAi methods, and research inroads

“…Management of fungal pathogens relies on preventing infection at the earliest stages of Cannabis cultivation, and minimizing the spread of spores. Fungi infecting pre‐ and post‐harvest inflorescence tissues are likely to be the most damaging to the medical Cannabis industry, especially those of the genera Botrytis , Fusarium , Penicillium and Golovinomyces 20–22 . In indoor cultivation, pathogens can easily spread via air and recirculated water; in outdoor cultivation, pathogen spread is more dependent on wind, rainfall and proximity to fields containing alternative hosts 20 .…”

“…Other partnerships are likely to form in this regard, given the potential for combining these biotechnologies towards the control of difficult fungal and viral pests. For example, a number of microbial pathogens can be present on Cannabis seeds and potentially infect the growing seedling 19,20,22 . For scenarios such as these, dsRNA seed treatments may eventually prove to represent a breakthrough RNAi technique for target‐specific management of certain fungal and viral pests of Cannabis crops.…”

“…For example, a number of microbial pathogens can be present on Cannabis seeds and potentially infect the growing seedling. 19,20,22 For scenarios such as these, dsRNA seed treatments may eventually prove to represent a breakthrough RNAi technique for target-specific management of certain fungal and viral pests of Cannabis crops. However, this technique may only prove effective against pests that colonize the crop during early stages of plant development, given the eventual degradation of dsRNA within plant tissues.…”

“…Fungi infecting pre-and post-harvest inflorescence tissues are likely to be the most damaging to the medical Cannabis industry, especially those of the genera Botrytis, Fusarium, Penicillium and Golovinomyces. [20][21][22] In indoor cultivation, pathogens can easily spread via air and recirculated water; in outdoor cultivation, pathogen spread is more dependent on wind, rainfall and proximity to fields containing alternative hosts. 20 The most serious viral pathogen in indoor Cannabis cultivation is hop latent viroid, which causes a stunting in growth/ development of inflorescences.…”