Gustavo Martins
Omono
Considering that we are messing around with our plants, cutting here, pruning there... I'm curious about how many of us actually disinfect tools after use, how often and with what...
Sorry to hear about your maples.I dip mine in alcohol, usually by pouring a little alcohol in my palm and thoroughly dousing the tool. I do that between trees when I'm doing any substantive work. But I wasn't doing things that carefully two years ago when all my maples turned black and died. I learned the hard way.
I'm still careless when I'm just pinching/clipping growing tips, but that's almost every time I look at a tree this time of year.
I asked some of the phytopathologists i work with about how much sense it makes to do a quick wipe.
None. None at all. Ethanol and isopropanol kill by elongated contact (is that a correct sentence?) Anyhow, for those to effectively kill, you'd need 15 mins of contact. A wipe evaporates way faster.
I do plant tissue culture clean ups on a weekly basis.
Here are some company secrets:
- Ethanol is effective in the 70-80% range. Any higher or lower % contains either too much or too little water. Targets: fungi, bacteria.
Time: at least 15 minutes of thorough/submerged soaking for tools.
- Chlorine bleach (5%) solution with detergent (tween or dishwashing soap) is pretty effective on everything. Plants will die after long exposure. It will damage metals.
Time: 5-50 minutes for tools.
- Peroxide (3%) effective for fungi and yeasts.
Time of submerging is around 5-15 mins. Does damage every metal, can soften wood.
- Freezing: doesn't work.
- Organic solvents (ether, hexane, butanol): pretty effective, pretty dangerous to work with.
Boiling water: 10-60 minutes. I found soil microbes that survived 90 minutes of boiling water. Those were beneficial. But if they werent.. Well, you could imagine ;-)
Dry heat: 300 degrees C, or the highest setting on your oven. Works pretty darn well! Melts plastics of course.
Pressure cooker: 15 mins per.. ehmm.. per 4 tools. 15 minutes is the minimum, 45-90 is best, more is a waste of energy.
So would soaking the blades in a cup of alcohol for 15 minutes work?I asked some of the phytopathologists i work with about how much sense it makes to do a quick wipe.
None. None at all. Ethanol and isopropanol kill by elongated contact (is that a correct sentence?) Anyhow, for those to effectively kill, you'd need 15 mins of contact. A wipe evaporates way faster.
I do plant tissue culture clean ups on a weekly basis.
Here are some company secrets:
- Ethanol is effective in the 70-80% range. Any higher or lower % contains either too much or too little water. Targets: fungi, bacteria.
Time: at least 15 minutes of thorough/submerged soaking for tools.
- Chlorine bleach (5%) solution with detergent (tween or dishwashing soap) is pretty effective on everything. Plants will die after long exposure. It will damage metals.
Time: 5-50 minutes for tools.
- Peroxide (3%) effective for fungi and yeasts.
Time of submerging is around 5-15 mins. Does damage every metal, can soften wood.
- Freezing: doesn't work.
- Organic solvents (ether, hexane, butanol): pretty effective, pretty dangerous to work with.
Boiling water: 10-60 minutes. I found soil microbes that survived 90 minutes of boiling water. Those were beneficial. But if they werent.. Well, you could imagine ;-)
Dry heat: 300 degrees C, or the highest setting on your oven. Works pretty darn well! Melts plastics of course.
Pressure cooker: 15 mins per.. ehmm.. per 4 tools. 15 minutes is the minimum, 45-90 is best, more is a waste of energy.
Offtopic:
You store petri's in ziplocks? I use cut-to-size cling wrap rolls for my fungi. It seems to hold longer than parafilm and I have some cultures over 2 years old still thriving without ever having opened the dish. I'm guessing there's good aeration, but not enough to let moisture escape fast enough to dry it out in the course of 2 years. At home I replaced agar with cardboard, I found it a lot easier to work with compared to agar. It's harder to select hetero-/homokaryons though, but for maintenance it's awesome stuff! And dirt cheap, easy to sterilize, easy to cut to size, easy to store, it has a higher surface area due to it being curved/waved.. If only I knew that back in the days..
As for flowhoods, hands are washed when entering the room, I clean my hands with 80% Etoh when they go in, but that's it. No gloves and no sleeves (because we're convinced that sleeves shed dust particles, and gloves don't have skin grease that captures micro-organisms, especially in the joint areas. I used to disagree with that practice, until after a year or so of doing it like this. We're dealing with a <0.25% infection rate in plant media (handling about 2000-4000 containers per week), so that's actually pretty low all things considered. Especially considering costs. Back in another lab, I used 200 sets of nitrile gloves a week, AND all the alcohol we could find (that's 40 bucks worth of material). Results were worse, infection rates were around 1-3%.
Back on topic:
I think it's all about ease of mind. I mean, working on sick trees is a no-go to begin with. You'll be damaging wood and structures that the plant is actively either trying to support/strengthen, or structures that it's trying to kill to get rid of the infection (apoptosis?).
If your tools are clean, but your cutting paste isn't, then what the hell does it matter?
If your trees are outside for longer than a millisecond, they'll be covered in spores no matter what.
If your trees are indoors for longer than a millisecond, they'll be covered in spores no matter what.
The air is full of it, the tree is full of it, and most micro-organisms living on trees are actually supportive and protective towards their host. One of the prime examples of why honey can be (note CAN!) beneficial. It doesn't only supply the tree with nutrients, it also helps the micro-organisms in protecting the wound.. At least from a distance; high loads of sugars are deadly for every life form with one exception, the tardigrade.
In a way, not cleaning your tools could be as beneficial as cleaning them; there's leftover tree sap from which water evaporates which causes concentrations of solutes to rise, there's natural antibiotics in it, cutting in dense wood creates so much friction that even bacteria can be pushed out of crevasses in the metal. It's a discussion where nobody is wrong or right, unless they're working on sick/infected trees. Ok, and unless they're keeping their tools in a compost bin or a watering hole. Then they should definitely sterilize. Not disinfect, but sterilize. Disinfection is superficial (like a 'clean sink' in a bar), sterilization is thorough (like a sink in a bath of lava, covered in acid, surrounded by sulfur fumes: nothing survives).
Fungal and bacterial outbreaks usually don't come from the tools alone, they come from poor maintenance, poor plant vitality, bad aeration, impatience and in 90% of all cases: over watering. I've done it all, I keep doing it, and it'll take another 10 years for me to finally stop doing it. But I gave up fighting battles. I made it sick, I killed it, I take the responsibility. Sometimes, there's just nothing to save anymore and we should acknowledge that. It hurts like hell, it does a nasty piledriver on our ego, but it's a learning point nonetheless. Those are priceless. I'm a hard learner like that. The best antibiotic is a healthy tree, it disinfects itself when necessary.
Fungi and bacteria (and archea, and yeasts) need to meet a pretty extensive list of demands to thrive. The "core dry nutrition" is the tree, but all the rest needs to be provided in some way.
In general: Just try to grow some wood loving fungi species yourself, you'll see that it's actually pretty hard to get a good thriving non-store-bought culture of Reishi (g. Lucidum) or Shiitake, without having to deal with Trichoderma (generally a plant protecting fungal family).