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Fusarium Spp.

Hey folks, figured I'd write this here hopefully it helps someone else battling this, I know there's a few. Also would love to hear from anyone who successfully battled this. I've read a few threads where this wiped people's large scale grows out, and even followed them to new spots. I've become unfortunately aware of how hard a problem this is to eradicate once you have it. I was one of the people who was confident I could fix ANY plant with the right TLC. That's because I had not run into fusarium before.

Problem started initially showing as deficiencies. PH and nutrients were spot on. There were no bugs. Environment was the same as it had been for 8 years succesfully.

After trying everything we could think of, we finally sent samples to a lab who narrowed it down to Fusarium Spp. Roots and crown infected, leaves and stem clear. In other words it is not the Fusarium Wilt variety, but the root version. Unfortunately, certain forms of Fusarium root rot travel several inches up the stem inside the vascular tissue, then create sometimes visible sometimes very small lesions. From there it shoots out spores 1-2 m distance. In other words it will infect your entire room in a hurry.

There is no known method of eradicating fusarium once a plant has it. Even the best preventative measures, once it is introduced into an environment only showed 80-90% efficacy. Only hope is cull every single plant, disinfect religiously, and start over.

Fusarium controls we have tried on mother plants include

Clearly 3336 Effective but phytotoxic in high doses and only provides control not eradication.

Heritage DF Best of the bunch, but again, it comes back.

Empress Intrisnic Same as Clearly 3336. Definitely a noticeable difference in plant vigor however (Pyraclostrobulin lowers plants respiration and aids during stress, helpful in root pathogen scenarios)

Cap's Bennies Am sure this would work great on Pythium and Phytopthera, Rhizoctonia and Fusariam especially is asking too much. That is no slight on his product, because the agricultrual industry has searched for an effective fusarium curative control for 80+ years with no luck.

Long story short, nothing is curative. If you say you have something that cured Fusarium, and I mean cured, not helped the plant limp to harvest, then you did not have Fusarium, or you deserve the Nobel Peace Prize if you release your cure, as this decimates many food crops world wide.

For clarification here, I do not advocate the use of harsh chemicals on food/consumption products. These chemicals were used on mother stock ONLY. By the time it becomes a clone, roots, then grows into a 2+ foot tall plant there is zero residue due to degredation of the chemicals as well as the simple fact that the plant is now 1000+ times its weight in mass. And that was while still in Veg. Multiple lab results have verified this for us.

Currently in the process of re-painting with anti mold paint, floor walls and ceiling, 40 PPM bleach spray down, then 150 F heat treatment for several hours. Installing disinfectant footbaths at doors and placing HEPA filters throughout rooms.

Will be taking cuts from plants that have the Fusarium for one try to see if our version is fully systemic. Lab results came back stem and leaves negative, but the spores are very likely residing on the surface of plant material. Will be dipping cuts in 20 PPM chlorine for 20 mins. 14 PPM for 6 minutes eliminated 100% of fusarium spores in tests.

http://hortsci.ashspublications.org/content/44/1/157.full

Cuts will be going in rapid rooters with a large dose of microbes plus EM-1 tea. PH is going to be high, 6.5, as research on many forms of fusarium considers "fusarium suppressive soils" to have a high PH.

Chemical fungicides often and in our experience do inhibit root initiation. After roots are showing, they will be given a single application of Empress Intrisnic followed by a single application of Heritage as a preventative. Research as also shown that many fungicides can be run in conjunction with beneficial microbes. General rule of thumb is the contact ones are not a good combination, systemics perform better in conjunction, but check on tank mixes before trying any new combo.

Temps will be left at 62 during rooting. Our version of fusarium 100% grows faster in higher temperatures. Some do not, but ours does. Fusarium is opportunistic. When a plant is being cloned that is the perfect time for it to take a foothold, due to the open wound at base of stem. Once root initiation has occured, root zone temps will be raised to 68F.

Finally, be very careful out there folks. This pathogen is hardcore, and the more I read about it and the more experience I get dealing with it, the more it daunts me by how resilient and invasive it is. Look out for dark tan/red roots that are not slimey. Or reddish discoloration at base of stem. Another tell tale sign is white roots with necrotic tips. Very similar to rhizoctonia in that regard. Will update more as this progresses.
 
I think I may have this in one room. Phantom deficiencies and complete defoliation by the end of flower if left untreated. It hasn't spread to any other rooms but anything that goes in this system gets it. Physan 20 at 1ml/10 gal and the plants are back to normal.
 
Forgot to mention those ones too, Physan, Zero Tol 2.0, Calcium Hypochloride and good old Hydrogen Peroxide, Zero Tol 2.0 has performed the best, but its all temporary. Roots go red to dark tan within a day of being watered. As medium dries out, white roots appear. Then process repeats itself next watering.
 
Those ones are the contact killers. They are for a quick knockdown. Systemic issues those are just a bandaid. In DWC or NFT I suppose you could run Zerotol 2.0 at about 800+ ORP and you would never see fusarium in your roots even if spores were everywhere. but your plants would be close to death from phytotoxicity. Thats the annoying thing about fusarium. What's strong enough to kill it, at least when its not deep in the stem, well it kills the plant too. We did have one test come back negative. A test clone treated with Zerotol 2.0 at 1/20 dilution. (Max recommended is 1/100). Killed the clone
 
Another interesting fact I read about fusarium is that 90% of the airborne spore spread occurs at night. Makes sense due to higher humidity and less UV for a soil/medium based virus.

No studies have been done on the idea of whether 24 hours of light in Veg would slow down the spread, most of these papers are in field/greenhouse conditions not with artificial or supplemental lighting.
 
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chris harris

Good luck. I lost a battle to fusarium many years ago. Was recommended to me to run ozone to kill airborne sores.
 
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chris harris

No. Lost the genetics, ended up starting over. Was systemic, passed thru to cuttings, couldn't out run it. Tried taking cutting, as so as viable, from fresh new growth, but it was passed on.
Was able to run again in the same location though after a thorough scrub down. Ran an ozone generator for a month, or so, after, so, maybe it did something, but couldn't save what I had.
 
Understood and thank you for the info. It does seem the safest option after disinfection is just to simply toss everything and not try to take cuttings. I have already accepted every plant we have is a loss, but was going to try to preserve some of the genetics. Is probably just going to be a waste of time however and the logical decisive option seems to be destroy everything.

Another interesting article about high air flow activating plants SAR innoculated with fusarium, and inhibiting the fusarium colonies substantially
 
Just for clarification Chris what symptoms were your plants showing? Was it the wilt variety of fusarium, where when lights were on all the branches and leaves would fold down? Or the root variety where the plant was obviously unhealthy, but limped along.
 
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chris harris

Forgive me if memory is a little faint, as this was almost 15 years ago. It was root fursarium. Plant looked somewhat ok in veg, a little pale, small root mass, stunted growth. During flower, plant would just start to yellow, drop leaves, and slowly die. If you were able to finish, pathetic small buds, no flavor or smell. This was on a strain that you could pull at 7 weeks, large yielder, beautiful flowers. If it was something that went 10 weeks, you would never make it, it would be dead.
Yes I would cut my losses and start over.
 
Did you ever try sterilizing your cuttings Chris? I read articles where 14 ppm bleach killed 100% of fusarium spores in 6 mins. The lab tech I spoke to was very certain that fusarium root and crown rot should not be in the growing shoots as it's very site specific. He said any contamination would be carried over from airborne spores resting on surface of leaves. Being a long time ago I'm not sure if you remember sterilizing the cuttings to that extent but just curious?
 
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chris harris

No, never tried sterilizing, never knew it was an option at the time. Had already invested to much time in trying to recover (almost 2 years), so I just baled out . Sorry I can't help more.
 
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chris harris

Your a brave man. Good luck. Update this thread if you can, I'd be interested in hearing if it works for you.
 
Its considered standard procedure for alot of greenhouses, hard part is finding the right concentration that eliminates all surface pathogens but causes no phytotoxicity or delay in root initiation. I'm hoping 20 PPM is not too much, tested it on 50 cuttings and they still perky, its still too early to see if it affects root initiation however. Of course this is all pointless if this fusarium is a true systemic however. Will definitely update.
 
Spent all day repainting clone room with Zinsky's anti mold paint. As soon as ozone generator arrives going to run that all day. 10 G Per hour output, I read that 20 mg/l killed 99.9% of fusarium within 20 minutes. Unfortunately in a 10X10 room I think I will only get it up to 15 mg/l. Might run it for 24 hours, just in case going to spray entire room down with 200 PPM Bleach solution, and then heat room up to 150 F for a few hours. Adding a UV filter to RO unit, footbath with disinfectant in doorway, 6 inch HEPA filter constantly on, rapid rooters will have a massive amount of beneficial microbes innoculated, long story short if these root and test positive for fusarium again, the only source could be from the mothers and that it's truly systemic.
 
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