Transcript

Ozone · Hydroponics Daily

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Hi, welcome back to Hydroponics Daily. I'm Dr. Russell Sharp from Goldleaf,
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or as it's called in the UK, liquid gold. And today I'm talking about ozone.
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And normally when we think of ozone, we have quite a positive opinion of ozone
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because it's in the ozone layer up in the stratosphere where it protects us from harmful UV.
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And then you've heard of the damage to the ozone layer, and this was caused
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by a number of ozone-destroying compounds,
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cfc's being a main one it was also caused by methyl bromide which was a soil
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sterilant that farmers used to kill off all the pests and pathogens and then
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that was banned in certainly in the uk and the european union in 2009 you can't
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use that anymore anywhere i think globally.
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Margaret thatcher had a lot to do with banning that so when everyone thinks of
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margaret thatcher as being this don't think of as being like a environmentalist
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but without margaret thatcher would never have been banned globally she sort
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of knocked out all these blokes these leaders world leaders heads together and
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got it banned so yeah that's even if you're anti-tory or anti-conservative in
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the uk margaret thatcher can be thanked for saving the ozone layer.
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And so yeah farmers are now left with other soil sterilants
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so steam and things like this which are not effective so actually
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banning methyl bromide has actually
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led to more and more hydroponic growing because people
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aren't growing things like strawberries and raspberries in the
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soil as much as they used to they're now growing them hydroponically and
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lettuce and things like that but i want to focus on tropospheric
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ozone so we live in the troposphere and we
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most of us live in urban areas and ozone
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there is not a good thing because ozone in
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the troposphere is a it's a human
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pollutant but more importantly it's a
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pollutant to plants so it is toxic to humans and it's
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part of it leads to the generation of photochemical
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smog in cities so where
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you get nitrogen oxides carbon monoxide
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ozone uv lights this and
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and particles from from fuel this leads to the the creation of photochemical
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smog and so in some cities this is terrible so los angeles is famous for photochemical
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smog and liverpool was famous back in the 50s for its pea supers this like green smog.
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Where I'm from, I've witnessed some absolutely awful pictures of people with
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no teeth and white hair from the smog.
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So ozone is part of that, but more importantly, it's a direct toxin to plants.
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And as I say, it's more toxic than it is to humans.
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You'll know ozone because when you put a food processor on, or one of these
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food ninjas, bullets, things like that, or a laser printer,
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that sort of geranium smell that you get out the back of it when it's going high voltage,
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I think it is, that the smells of geraniums that is
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ozone geraniums don't give off ozone but that's that
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that is the smell it just smells similar to the same chemical
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that's given off by geraniums anyway i'm waffling ozone it's
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really bad for plants it leads to necrotic lesions so black
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death on on the plant in really high levels it increases increased senescence
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the pollen can become sterile the plants become unresponsive to drought and
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frost but they're very difficult to diagnose ozone and you probably wouldn't
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know that it was happening.
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The times of year where you're going to get really high levels of ozone in urban
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areas is when you would normally be saying, isn't the weather wonderful?
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So if it's really sunny, it's really warm, and it's very still,
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and you're in an urban area, you're going to have really high ozone levels.
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And if you're growing a crop indoors then you're going
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to have that's going to be causing some significant
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damage to your crop plants will produce
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antioxidants to overcome the oxidation
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of these the effect of ozone so
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ozone is o3 it's a three ozone oxygen
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is normally got two atoms in the
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molecule so o2 we think of o2 we breathe in
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o2 use o2 o3 is a very unstable triangular shaped
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molecule and so it reacts and it causes oxidation
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of chemicals in your body so that's why you produce you
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eat antioxidants like vitamin c that's why plants produce
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antioxidants so if you in if you
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expose plants to a lot of uv and a lot of ozone
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they will create a lot of antioxidants and that
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can be a good thing or it can limit the growth and
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it can stunt growth and it can cause necrosis so
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it depends on your crop and when you're going to use it if you
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are going close to harvest and you're wanting to increase your antioxidant levels you
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could play around with extra uv and you could play around with adding ozone
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if you wanted to but ozone is normally added and uv are normally added as sterolence
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away from the plants themselves plants are particularly toxic sorry plants are
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particularly sensitive to ozone include are supposedly heather and buddleia.
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From my experience, Heather and Buddleia are two of the hardest plants going.
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And if that was the case, then Buddleia wouldn't thrive in urban environments.
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And Buddleia grows everywhere. It grows on the sides of buildings.
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You go around Leicester, that's the closest city to me, Buddleia is growing
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out the roofs of all the abandoned mills and clothes factories there.
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So I don't believe that Buddleia is particularly sensitive to it.
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And heather again you know that grows in
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well in bad environments i honest on
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a side tangent here i'm gonna waffle some
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more i have this theory that buddlia is
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the most successful plant in the entire universe because if you watch old episodes
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of doctor who they always filmed in a quarry somewhere in the midlands of england
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and there's always a buddlia plant in the background So every planet that Doctor
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Who went to, Buddleia was there.
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So Buddleia is the most successful plant in the universe if you live in the Doctor Who universe.
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So yeah, do we believe Buddleia is the most sensitive? I don't think so.
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Petunia is particularly sensitive to ozone apparently and it produces smaller flowers.
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Now if you're growing a flower crop, flower buds, you don't want smaller flowers.
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So what can you do about it? well you could
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go on and spray vitamin c or another
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plant hormone a plant hormone called methyl jasminate they've been
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found to increase the plant's tolerance to ozone however
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there's a tip here that most hydroponic
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growers in the uk in the us will actually
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be able to implement fairly quickly and that is activated charcoal
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now activated charcoal absorbs and
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deactivates ozone now what would you do
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to prevent ozone getting into your grow room rather than
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just putting an activated charcoal filter on the
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on your outlet of your grow room as you normally do
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you could put one on the inlet to
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your grow room and this in very hot warm
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still conditions in your urban areas you could
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remove all the ozone you know if i
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was growing in an urban environment i'd stick a carbon
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filter on there in the summer i mean if you're growing in the summer indoors
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it's tough anyway you know only the
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experts grow in the summer hydroponically it's
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easy to grow but it's easier a lot a lot easier to
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grow in the winter because you don't have to deal with the
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extra heat but if you've got a really hot day i'd stick it i'd stick an extra
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activated charcoal filter on the inlet the good news is that ozone can also
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affect plant pathogens so So they are a biological organism and they will be sensitive to ozone.
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So some pests, sorry, some diseases might become less prevalent if you've got ozone.
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Hopefully if we move to.
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Cars and vehicles that are not producing carbon monoxide
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and nitrogen oxides from their emissions
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then hopefully ozone levels will decrease so
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hydrogen fueled electric cars pedals you
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know pedal power if you get on your bike then you'll
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reduce the amount of ozone in urban environments it'd be
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interesting to see what happens if if we do move towards not
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necessarily less emissions but less emissions in urban areas
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then this could we could reduce the we could
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increase our plants tolerance and certain plants
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could grow better in urban environments one plant
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that does is particularly tolerant is tree
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of heaven and that is a
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really interesting plant because that is that has a number of really interesting
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biological features it's a weed in the united states
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it's becoming an invasive weed in the uk but it's
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got a lot of interesting things about biology that makes it highly adapted
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to living in in urban areas it
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produces suckers that can travel many meters and it's
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got some interesting biochemistry in there it's related to
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huma sumac sumac sorry that that spice it's got a lot of poisons in i think
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as well though tomatoes are supposed to be tolerant to ozone i'm not sure how
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about that is a punty of the cactus that is extremely tolerant to ozone not
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only because it only opens its tomato at night because it's a
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It has something called CAM photosynthesis, crassulaic acid metabolism.
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Yeah, get that science in for you. So all cacti, they open their stomata at
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night and then absorb carbon dioxide as acids.
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So they won't be exposed to as much ozone because their stomata aren't open
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when the most ozone is there during the day, when the UV light's hitting those
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carbon monoxide molecules.
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Not only that, cacti are just really tolerant, tough plants.
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And i've experimented with ozone tolerance
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and exposing plants to to ozone in
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ozone chambers up in lancaster university
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in the lancaster environment center so we had a number of ozone
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chambers and ozone generator and we could monitor the ozone levels that's normally
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quite difficult because ozone monitors are quite expensive so you can just install
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one in a grow room but we did this and found that you know you could pump so
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much ozone into these chambers that would normally kill a baby really with the
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amount of ozone that was in them and.
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These Apuncia plants just thrived so Apuncia tree of heaven,
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maybe tomatoes. These are tolerant to ozone. So that has been hydroponics daily for today. Ozone.
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Maybe you've got an ozone generator. Maybe you've got a carbon filter and you
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might be thinking, you know what?
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I might buy an extra one and stick it on my inlet just for those wonderful days
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when we've got wonderful weather and your plants are screaming with pain,
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but you can't hear them because it's very difficult to diagnose the symptoms.
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And it's very difficult to actually well it's very expensive to buy an ozone
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monitor and it's not something you wouldn't regularly do unlike a co2 monitor
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or soil moisture measure probe okay that's enough waffling from me today thank
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you very much for listening that's been hide upon it staling cheers.