Researchers identify pathogens infecting cannabis plants in Connecticut
Recreational cannabis became legal in Connecticut last month and as local growers expand their footprint, researchers from the University of Connecticut are tracking pathogens infecting plants.Ph.D. candidate Cora S. McGehee and associate professor of horticulture Rosa E. Raudales from the College of Agriculture, Health and Natural Resources recently published the first paper documenting the presence of pathogens in Connecticut’s cannabis growing facilities.
“Once infected, it’s very difficult to revive the plant and use it for profit,” McGehee said in a news release. “It’s pretty much a goner.”
In addition to 21 isolates of Pythium myriotylum, the researchers also found one isolate of Fusarium oxysporum and three isolates of Globisporangium irregulare.
To conduct their work, the researchers took samples from the seedling stage, mature plants, and soilless substrate samples from the coconut coir and Rockwool the infected plants were growing in. The aim of the study was to investigate if soilborne plant pathogens were present in soilless substrates from a commercial cannabis growing facility.
Some samples were sent to Yale University and Eurofins Genomics LLC laboratories for sequencing so the researchers could match the samples against a national database.
From there, the researchers set up hundreds of hemp plants and intentionally infected them with the pathogens at UConn’s Plant Science Research greenhouse, which confirmed that all the species and isolates tested were pathogenic to cannabis plants.
The study also noted that the pathogens were sensitive to mefenoxam, but this chemical is not labelled for use on cannabis.
Monitoring pH and water levels and using biological fungicides are strategies growers can use to catch and reduce the damage caused by these pathogens. Once a plant becomes infected, it should be removed as soon as possible to reduce spread, the researchers note.
“It’s important for growers to start matching these diseases with the pathogens that cause them,” McGehee said. “I think that will help management strategies and prevent disease outbreaks in their facilities.”
