Bob with the win, yet again!
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@Enjoi802 be sure to let us know what you use to kill them. Knowledge is power!!!
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https://cdnsciencepub.com/doi/pdf/10.1139/cjb-2022-0139
Understanding bud rot development, caused by Botrytis cinerea, on cannabis (Cannabis sativa L.) plants grown
under greenhouse conditions
Mohannad Mahmouda, Ines BenRejeba, Zamir K. Punja b, Liam Buirsb, and Suha Jabajia
Plant Science Department, MacDonald Campus of McGill University, QC, Canada
Department of Biological Sciences, Simon Fraser University, 8888 University Drive, Burnaby, BC, Canada
Corresponding author: Z.K. Punja (email: punja@sfu.ca)
Abstract
Botrytis cinerea is a widespread necrotrophic plant pathogen that causes diseases on >1000 plant species, including vegeta- bles and ornamental greenhouse crops. On cannabis (Cannabis sativa L.), the pathogen is responsible for causing “bud rot”, a major disease affecting the inflorescences (compound flowers), as well as seedling damping-off and leaf blight under certain conditions. During greenhouse cultivation, Botrytis cinerea can destroy cannabis inflorescences rapidly under optimal relative humidity conditions (>70%) and moderate temperatures (17–24 ◦C). Little is currently known about the host–pathogen in- teractions of Botrytis cinerea on cannabis. Information gleaned from other hosts can provide valuable insights for comparative purposes to understand disease development, epidemiology, and pathogenicity of Botrytis cinerea on cannabis crops. This review describes the pathogenesis and host responses to Botrytis infection and assesses potential mechanisms involved in disease re- sistance. The effects of microclimatic and other environmental conditions on disease development, strategies for early disease detection using prediction models, and the application of biological control agents that can prevent Botrytis cinerea develop- ment on cannabis are discussed. Other potential disease management approaches to reduce the impact of Botrytis bud rot are also reviewed. Numerous opportunities for conducting additional research to better understand the cannabis–Botrytis cinerea interaction are identified.
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I’ve got a gizmo called the AirROS by a company called Sage.
It releases Reactive Oxygen Species into the air and kills PM and spores in the air and on all surfaces. You run it all the time, it’s not hard on the plants.
I had 3 grows in a row with PM and finally solved the problem with the AirROS. It’s relatively expensive but it’s worth it to save a grow.
.
Home - AirROS by SAGE Commercial Surface & Air Purifiers (airrosshield.com)
2 years and not a bit of PM.
.
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Don’t know if it’s been mentioned, but here is as good an answer to PM (and other issues) as it gets
https://overgrow.com/t/hypochlorous-acid-a-deep-dive
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Micronized Sulfur…everytime
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Not in flower…H.A. all the way.
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I can confidently say I have defeated powdery mildew , thrips and staved off spider mites from getting a foothold.
How did I do this?
Last fall I sprayed the sulphur as per @JoeCrowe 's advice.
I sprayed all my vegging plants, the soil surfaces the pots the floor the walls…even misted it thru my fans. Then I went outside to the greenhouse and sprayed down the floor the walls the ceiling , inside my light dep shed floor , walls and ceiling. Then I sprayed a 20 foot perimeter around the greenhouse.
So this year I weed wacked the spring weed growth inside the corners of the greenhouse and a few feet around it and then did the spray down again and included all the vegging plants, soil surfaces and pots as well as the pots and totes that were used for final transplant. Before the plants went into the greenhouse I sprayed floor. walls and ceiling of greenhouse and lightdep shed and the 20ft perimeter around the greenhouse. I also added the sulphur as an ammendment in my soil mixes.
I am about 50% though harvest and not a spec of PM anywhere. Not even the grasses and weeds around the greenhouse have it . Conditions have been just about perfect for PM and Fusarium but this year… mold and mildew free harvest. I think the sulphur spray also helped keep the mites and western flower thrips from getting a foothold again too.
For thrips… I use Monterey’s Garden Spray With Spinosad and get both sides of the leaves and the soil as well as the surfaces of the pot… especially underneath. Also spray the grow room floor. Be warned though… Spinosad is bad for Bees so spray indoors or if your greenhouse is sealed with bug screens .
I’m researching the hypochlorous Acid because the sulphur spray can’t be used in flower.
I don’t have PM this year because I practiced an eradication strategy in advance and I am so happy with this years harvest I feel I should send a thankyou care package to @JoeCrowe
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Here’s the badge I made up for the mildew assassins! You earned it!
Once you are up inside the mildew’s head, it’s game over. Know thy enemy!
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I will second your experience. After fighting PM last year, and the couple years before, took Joes advice and sprayed sulphur early this year in the swamp. Worked awesome!!!
Now, this year, no PM anywhere, BUT, Septoria is running rampant thru just about everything this year. My Apple tree was decimated by it, my Maples have it, Poplars have it, wildflowers we keep for the bees have it, my back 2 1/2 acres, it’s on damn near every tree, and it took a toll on my plants, as I couldn’t hardly get back in the swamp to do any prevention whatsoever because the mosquitoes are out by the Billions here this year, and couldn’t find a bug Spray the would even work, worst I’ve seen mosquitoes in 17 years of living at my house.
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In the center of some packed areas week6-7 of flower found two leaves like this very small spots. I want to tell myself it could be from some of these other resinous buds but this is pm ain’t it? I had it spread to everythung beforenso I’m just so 50/50 on tossing everything I have again before wasting anymore time. Haven’t seen it in any other tents tho. All veg plants I rotate zerotol hc and sulfur sprays on.
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Someone just liked my post…thank you! I was looking for LAB info and this just answered my question.
Just checked…thanks @Heavenlygoo !!!
I was looking for LAB answers…should have been looking for PM answers…lol…I don’t have PM…just want LABs…lol
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Mixing sulfur with water and spraying is a relative pain. It took me about an hour to spray everything the time I did that. This way works much better, and took me 15 minutes to do about 40 plants. Plus, now it’s on the shelf and I can just grab it. I don’t have to mix it with water.
- Put the powdered sulfur in a salt shaker,spice shaker, whatever. I used an empty seasoned salt jar.
- Very gently shake over the canopy until it’s well-covered. For bushy plants with a lot of leaves, you might have to shake inside, under the canopy as well.
- Tap-tap-tap on the trunk, hard enough to shake the leaves a little. This will distribute the sulfur everywhere, even on the underside of leaves.
That’s it. Wait a week, then rinse the sulfur off.
Or you could use hypochlorous acid, don’t wait a week…kills it on contact, and you don’t have to rinse it off, its organic.
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Not sure if it has been mentioned but JADAM sulfur and JADAM wetting agent.
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