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Root Aphids - unearthing a mysterious pest · Hydroponics Daily

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Yo, yo, yo. Welcome back to Hydroponics Daily. It's your main man,
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Dr. Russell Sharp. We're bringing you everything soilless cultivation.
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Today is an amazing podcast episode that's going to have you on tenterhooks.
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It's all about root aphids.
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Yeah, not something that immediately says, wow, this is going to be a banger
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of an episode, but it should be.
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Very interesting i sound like i'm drunk don't i
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i'm or hi i'm not the most exciting
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thing i've done today is walk around a cricket pitch five
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times and then realize oh sugar i've
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got a podcast to record and i've got this one in the
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bank a one about root aphids and it's
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one that i wanted to give full justice to so i've i'm
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gonna use a number of different sources root aphids are very
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important for hydroponic crops but they are very poorly studied
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one because they're subterranean and everything under
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the soil just like everything under the sea is very poorly studied
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because they don't like getting down and dirty and also because they don't affect
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many major staple food crops so root aphids are normally these things that sort
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of go on crops if they get in from weeds and and the and so the plants around
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your crops might be infected with them.
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There's a few ornamental plants that suffer from root aphids like roses,
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but for most crops they don't.
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But hemp and legal cannabis, it is a major issue, especially in places like Spain.
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A lot of growers in Spain, when I've been to shows in Barcelona,
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they've mentioned, God, we've got anything for root aphid, got anything for
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root aphid, it's a big problem.
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And root aphid is interesting because it's not like thrips or spider-mite.
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It's not the worst pest in the world. If you get it, it's not going to kill your crop.
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But it's not the most widespread. It's localised.
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It's not the most common pest in hydroponics.
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However, it's very difficult to diagnose.
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And once you've got it, it's very difficult, near impossible to eradicate.
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And so that's why I want to study it. And I want to talk about it.
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So there is, these are aphids, so like green fly, black fly, you might refer to them.
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That can be a number of colors they can be white they can
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be black they can be green just like aphids can be and they
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can be winged or wingless just like the aphids that suck the
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sap on the underside of your leaves however they're normally
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waxy and they leave a waxy deposit around
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the roots so on spotify you'll get
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the podcast episode artwork which
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you don't think comes through on on apple and probably comes
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through on amazon and you'll see these waxy deposits
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around the waxy aphids and they don't look
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like normal aphids they they look
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like they've got this waxy coat on
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them and they may not
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be always on the roots they may be
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on the stem as well so that's why people can get confused because
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they get aphids on the lower part of the stem or the lower
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leaves and they think well it can't be root aphid because they're
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not on the roots but they can be root aphids can go further
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up the plant and as i
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say they're poorly studied and most aphids they have
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a weird life cycle and i'm trying
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to stop saying the word so i just
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said it there it really annoys me because it's one of the biggest
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problems with my podcasting is saying right i'm going to do
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the rest of the podcast without saying aphids they have a life cycle that's
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very strange so they can give birth to pregnant babies mad isn't it they don't.
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Need to have sex to reproduce this is called.
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Parthenogenesis in plants it's also called parthenocarpi when
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plants can produce seeds carp is the latin
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for greek for seed parthenocarpi seeds without
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sex or without sexual transfer genetics
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whereas aphids parthenogenesis they
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produce pregnant young that just by mitosis
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and they they produce babies and so
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this is really quick process but they also
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have alternate hosts so they go from one plant
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to another to complete their life cycle and there's
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one that grows on willow plants and it's called the willow aphid the giant willow
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aphid largest aphid in the world and it grows in a graveyard about 200 meters
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from where i am recording this podcast there is a willow plant that's got these giant aphids on.
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And what's interesting about that is for a couple of months of the year,
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nobody knows where these giant aphids go.
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You can't put a tracker on an aphid. They don't know where they go.
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There could be root aphids that suddenly go into the ground.
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No one knows. No one's found out.
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If you could find where the willow aphid goes for those two months of the year,
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you would be a rock star in the entomology world.
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So there's something. If you're looking for an interesting study subject
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have a look at that and root aphids they're just the same people
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don't know much about them and i think there's going
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to be a lot of research on root aphids because it's becoming
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an increasing problem in legal cannabis and they're
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so poorly studied and so it'd be an interesting topic for
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people to study and i don't think a lot of these universities but again
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into the legal cannabis phase we'll we'll talk about root
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aphids coming up so we say the telltale
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style is this waxy secretion on the roots however i
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grow lots of plants in my greenhouse and in my grow rooms i
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very rarely look at the roots because i don't want to be disturbing the
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root system you know you don't want to be damaging roots because
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that will affect the plants and their ability to produce and their ability.
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To create yield and so that's why
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it goes undiagnosed so you might mistake a
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infestation of root aphids with a nutrient
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deficiency or a virus or some sort
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of environmental stress and then they'll
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get to the point where your plants are just keeling over and you go into
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the point where you're throwing them away you take them out the pots and
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then you see the root aphids and that's when you go oh sugar and
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then if you're growing in soil or you're growing in the in the
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soil in the ground then you're in for a world of pain because then
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you've got an infestation then you've got to get
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rid of so they can also be mistaken for root mealy bug and mealy bugs are related
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to aphids so they're a type of things and then you might probably the first
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sign that you've got root aphids might be ants going into your growing media
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because ants feed on the honeydew the.
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The the excretia of the
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aphids for a nice word and ants may farm
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the root aphids and move them around to different plants
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in your grow room or in your grow setup so
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yeah that's root aphids they as i say they might have a secondary host drought
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can similar can have a similar effect to the roots so and can exacerbate the
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issues what else can we say about root aphids there's quite a lot to say let
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me pause the podcast and just find my notes yeah let's talk about control so.
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First bit of control is quarantine making sure that
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you don't bring them into your your system especially you're bringing in plants
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from spain for example don't bring plants in
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your soil try and use snips or cuttings or seeds if
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possible obviously you know you want to that's not always
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possible in in crops like legal cannabis where you want to protect
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phenotypes and genetics and then
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soil sterilization is your only method
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now you can't just spray with an insecticide because it's
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not like just applying a small amount to a root you need to
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have a vast quantity to go into the root system because there's
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so much water in the root already there's so much material your
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chances of applying a root-based insecticide and that's
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not systemic to kill aphids is minimal
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you probably need to apply a systemic insecticide and
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then you have the issues of residues in
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your crop from that you could try steam sterilization
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of your growing media once your plants have been removed you could try
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peroxide treatment of your growing media but that
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will impact your roots what are the ways of sterilization have you got you can't
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use methyl bromide anymore that got banned by maggie thatcher because she saved
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the ozone layer a lot of people on the left-wing politics don't like me mentioning that, but she did.
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Methyl bromide was banned because of the Montreal Protocol. Maggie Thatcher
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bashed some heads together and banned CFCs and methyl bromide. And,
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So now we have an ozone layer, but we don't have a very potent seed soil sterilization chemical.
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At Eutrema, we have something called lime sulfur, which is an organic soil sterilization chemical.
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It doesn't harm the plants if used at low dose rates, but if you're using in
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rockwool, things like that, you can't really use it because it's a bit too spicy for the plants.
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So it's a bit hit and miss. You might want to start at a low dose rate if you've
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got root aphids and move up from there.
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It's so that's probably your best
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method of controlling root aphids when you've got crops in the
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ground obviously being an aphid they can transfer viruses so you could have
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secondary infection of viruses and other diseases obviously the symptoms of
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root aphids are seen on the leaves even if the root aphids aren't there so they
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will be it'll look like magnesium deficiency or iron deficiency.
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So if you see those, always check the roots before you start applying iron and
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magnesium just so that it's not that.
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Another top tip, when removing infected plants, always be really careful and
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dispose of all the growing media well away from your plants.
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Although you've probably got the whole grow room infected once you've got some,
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you're very very lucky if you get some in a grow room or a
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green house and then it's not affecting the whole whole material if
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you're growing in in sort of things like rockwool or
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aeroponics where there's less grow media or no grow
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media then you probably have more chance of controlling it and size
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wise we're talking one to three millimeters for
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the aphids so um that's something
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to suck in that sort of size range not the
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giant willow aphids which can be up to i think like up
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to a centimeter massive things maybe half a centimeter long
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and then control also sticky traps will help
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because they will fly between the plants and then
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preventing something called the green bridge so aphids if
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you can kill off all the plants and then not have any
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other plants in the grow room for three weeks in theory you
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kill the green bridge because aphids only survive on living
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plant material however we've had plants aphids in our
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grow room we've killed off all the plants left them
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for well over three weeks whacked up the heat reduced
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the humidity in theory all the aphids should have been
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dead but they still survived and infected the
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next crop along so remove all
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the growing media that would be my advice and disinfect the grow.
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Room wait three weeks just because one or two aphids
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might be around in a nook or a cranny
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blast it with uvb get
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a get one of those reptile um lights i mean
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you could even blast it with uvc if you can get a hold of uvc light
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but they will seriously
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damage your health if you expose yourself to uvc so you would need to put them
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on a timer or something like that you could put an ozone generator in
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the aquarium to to further sterilize it
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and things like that while the plants are not there so root ophids
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not a massive problem localized problems
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like places in spain not a problem on most
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crops problem on roses weeds grass
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species legal cannabis but and
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it's not a massive it doesn't cause major damage
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like like serious loss of crop entirely just weakens
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the plants and you know makes them wilted and things like
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that if you've got a really bad infestation it would obviously kill the
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plant off but it's a big issue because it's hard to diagnose and
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once you've got it it's really hard to eradicate so that's
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been hydroponics daily for today an amazing interesting episode all
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about the fantastic root aphids have something more jolly and or techie tomorrow
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if you found this interesting or you know somebody's suffered from root aphids
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please share this and if you have had it shared with you then please you owe
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that person who shared it with you a very large trink.
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Thank you very much for listening. Until tomorrow, this has been Hydroponics Daily. Goodbye.