
Rust on Hemp:
Dr. Gary Bergstrom confirmed hemp rust in a CBD variety trial in Tompkins Co. collected at the time of harvest. Here are pictures of upper and lower leaf symptoms. Jamie Crawford observed rust-like signs on leaves of multiple varieties and shared samples with me from the plots. Here are pictures of upper and lower leaf symptoms she provided. They are continuing to collect samples for further confirmation/ identification. The USDA Fungal Database lists no records of this fungus or any other hemp rust in the USA. An apparently identical rust has been observed recently in some southern states.
Since urediniospores are windborne over considerable distance, it is highly likely that the rust will show up in other locations yet this fall. No alternate plant host has yet been described for this fungus. Rust survival requires a living host plant. It is most likely to overwinter in deep South states on living Cannabis plants, though we should also be very cautious about survival over the winter on greenhouse grown plants in the North as well (a potential green bridge).
The source of this rust is mysterious. There is a surprising lack of articles in the literature or even popular Cannabis web sites about rust as a production problem anywhere, and that includes Europe. One potential scenario is that a low level of rust has been overlooked for years on native or feral hemp plants and that a few spores found a new home on cultivated, industrial hemp and completed enough spore production and infection cycles to be noticed at the end of this growing season. Rust is not transmitted in seed. It is possible the fungus could be introduced on infected, vegetative cuttings or with hemp tissues contaminated with viable spores. I wouldn’t expect the spores to remain viable for long (days to weeks, not months) so green Cannabis tissues are the most likely conveyance.
If you suspect rust, Contact Maire or your CCE educator to organize samples from any remaining hemp tissues you may come across this fall.
In the News:
Dr. Sanjay Gupta Weed #5 features CBD http://cnnpressroom.blogs.cnn.com/2019/09/23/dr-sanjay-gupta-reports-weed-5-the-cbd-craze/
I saw it last week and, certainly, there were tiny nuggets one could argue with. The most interesting piece was how much data Consumer Reports was gathering on CBD products and
Update: The Dr. Gupta piece features stories on the YOLO CBD vaping products that were deadly in some consumers. More information in this case has just been discovered about the source: https://www.latimes.com/world-nation/story/2019-10-20/california-woman-faces-prison-yolo-vaping-investigation
CBD Workshops – Newburgh, NY
For medical professionals : https://secure.occitizensfoundation.org/np/clients/occf/event.jsp?event=186&
For general public: https://secure.occitizensfoundation.org/np/clients/occf/event.jsp?event=187&
2020 2nd Annual Industrial Hemp Conference
Thursday, February 20, 2020, 9:00 a.m to 5:00 p.m. at the DoubleTree by Hilton, 870 Williston Road, South Burlington, VT 05403
The University of Vermont Extension Northwest Crops & Soils Program and Vermont Agency of Agriculture, Food and Markets are hosting the 2nd Annual Industrial Hemp Conference.
Visit our 2020 Industrial Hemp Conference page for updated information, including the registration site once it has been made available – go.uvm.edu/2020hempconference. We will again offer multiple breakout sessions, as well as the live broadcast option if you cannot attend in person. We are actively working on the list of guest speakers and presenters, so cannot share the detailed information at this time. All Conference Sponsors and/or Exhibitors MUST SIGN UP by November 15th. View the Reservation Form here (PDF). Registration fees will be $100 per person or $75 for the live broadcast. Please visit go.uvm.edu/2020hempconference to get updated information as well!