The Enigma of Myclobutanil for the New Legal Market
© By Judith Stamps; informed by interviews with: Geoff White at CanGenX Labs; John Coleman at Anandia Labs; and Alan at Strainly.
Myclobutanil (myclo), a fungicide sold commercially as Nova 40, or Eagle 20, came into public view in 2016. That year, BC Licensed Producer (LP), Tilray, petitioned Health Canada for permission to use it.[1] Permission was denied. Then in 2017, three LPs, Mettrum, OrganiGram, and Aurora, issued product recalls. Someone had blown a whistle; a few growers were using it, and some buds had tested positive.[2]
Is There a Problem?
Myclo is on Health Canada’s prohibited list for cannabis, and tobacco. It is similarly banned in Washington, Oregon, California, and Colorado. It is permitted on select food crops both in North America and the EU, as digestion renders it benign. But myclo emits hydrogen cyanide when combusted, and that does sound like a problem.
All the same, there have been no reports of consumers falling ill, ever. So the dangers may be exaggerated.
In its petition, Tilray noted that myclo was in common use among unlicensed growers. Health Canada asked them how they knew this. It was a silly question. Schmooze your way to the nearest informal grower, or acquaintance thereof, and you will learn that Nova, or Eagle, is available under the counter at grow stores, and continues to be a staple, especially on outdoor crops. Some cultivators believe that it dissipates within 40 days; others, that it is safe if sprayed on leaves, prior to flowering.
Creeping Toward Legality
Whatever the real danger, the practice of spraying with myclo is doomed. Illicit growers that have been using it, and are now applying for a grow license, are in for difficulties. They will want to bring their best cultivars with them. Here is what they will learn.
Myclo does not dissipate in 40 days. Moreover, it is systemic. It is stored in the plant’s subcutaneous layer, under the leaves’ waxy coating, and cannot simply be washed off. It also enters the plant’s circulatory system. If you spray it on the leaves, it will appear in the buds. If your mother plant has been sprayed, it will be detectable in your cuttings, and their subsequent flowers. If you are growing a seed crop, it can show up in the seeds. It is a proper gremlin. As myclo is now on the official radar, anything you wish to sell legally will be tested for it.
What To Do
In principle, one can purify a plant. A possible method is micro cloning. A small bit of original, contaminated plant matter is washed with a sterilizing solution, placed in a growing medium, treated with hormones, and then grown out. This process is repeated as many times as needed for adult plants to test clean. It can take up to a year to complete.
But thus far, micro cloning has been used to clear plants of bacteria or viruses only. It has not been tried for cleaning out systemic chemicals. It may not work; and the attempt would be expensive. At CanGenX the price is $5,000 per plant.
A simpler, surer technique is to grow out successive generations of cuttings, being careful to grow all new ones free of banned pesticides. At some point on this path, the myclo should no longer be detectable. But how many generations are needed to complete the journey remains unknown.
Into The Future
Myclo eliminates powdery mildew by disrupting its ability to grow cell walls. It works. So how does one manage without it? One method is careful control of temperature, moisture, and airflow in the growing environment, along with meticulous cleaning.
Beyond such measures, it is important that growers develop a strong lobby for sensible policies. There are organic solutions that build a plant’s resistance to disease: probiotics such as bokashi, or EM-1,[3] or compost teas. There is Actinovate,[4] a commercial fungicide containing beneficial bacteria. But plants treated in this manner will test positive for microbes, albeit good ones. Health Canada, which calls for almost no microbes, does not distinguish bad from good.
Lobbying, however, is slow. For now, the enigma of myclo seems here to stay.
[1] https://www.theglobeandmail.com/news/national/bc-pot-producer-sought-federal-approval-to-use-fungicide/article32122063/
[2] https://www.theglobeandmail.com/news/national/no-pesticide-testing-done-for-marijuana-health-canada-says/article33948779/?utm_source=facebook.com&utm_medium=Referrer%3A+Social+Network+%2F+Media&utm_campaign=Shared+Web+Article+Links&fbclid=IwAR1ukmEnuklvd143023drq9Fxzk8Z1Im98Bmb4eppmYJDqepjtUrAEqXaI0
[3] https://www.google.com/search?q=bokashi+tea+for+plants&ie=utf-8&oe=utf-8&client=firefox-b
[4] https://www.greenhousegrower.com/production/disease-control/actinovate-is-a-trick-up-your-sleeve/