S06 - Session O9 - Assessment of four biocontrol agents for their suppression of Fusarium proliferatum on Cannabis sativa plants in a soilless cultivation system.

Authors: James Nesbitt *, Marc Habash, Sarah Kingsley, Finlay Small, Youbin Zheng

The advancement of Cannabis sativa production for medical and recreational use has led to the rise of various disease causing pathogens. These cannabis pathogens can be perverse to control with current management practices and rely on multiple methods of control. High quality, medicinal cannabis is typically grown indoors in sterile environments, for its uniform and consistent properties. However, there are currently very limited registered pesticides for use on cannabis in Canada to protect these high value crops from disease outbreaks. Additionally, high use of pesticides can have adverse effects on human health and the environment, making alternatives to chemical pesticides highly sought after. The past few decades have seen the rise of consortiums of beneficial microorganisms used as alternatives to pesticides, aiding in management and suppression of harmful pathogens while promoting plant growth. However, there has been minimal work dedicated to beneficial microorganisms' ability to suppress endophytic pathogens such as Fusarium on cannabis plants in soilless systems. The objective of this research is to assess whether biocontrol agents containing beneficial microbial species can reduce the incidence and severity of Fusarium proliferatum on infected Cannabis plants grown in a soilless cultivation system . Two strains of Cannabis sativa , 'Duke Nukem' and 'Royal Goddess', were used in this trial. Transplants were dipped in one of four biocontrol agents (Rootshield WP, Jumpstart WP, Actinovate AG and Quickroots) before being inoculated with a liquid spore suspension of F. proliferatum . Control plants received either no biocontrol agents and no pathogen, or no biocontrol but with Fusarium inoculation only. Plants were assessed visually for disease symptoms weekly; lignin degradation and endophyte recovery were analyzed in vitro on the stems. This talk will present the results on the efficacies of the applied biocontrol agents in controlling F. proliferatum on cannabis and provide growers with alternative, sustainable means to control pathogens in their facilities.