Gary,
where can I get more information on using UVC ? I have heard it is a very effective tool but can be quite dangerous if not used properly.
Thanks David
1 Like
There is no one location for researching and understanding UVC lighting. I’ve looked at a number of forum sites, and googled information. There might be a lighting expert member on Growers Network that might be able to provide more information possibly and would be another great source for more information. Here is an excerpt from “Theherbalizor” on the THCFarmer forum that I found very helpful and informative.
Uvc is a light spectrum… Not a toxin. It is not toxic to plants.
However, it destroys and mutates DNA on long term exposures.
Germicidal uvc bulbs for horticulture are nothing new, infact cleanlight.nl make a hobby uvc light for use on fungus etc on house plants, weed.
This is not a gimmick, it works. Has been used in the commercial industry for years.
Floweryfields of Austria use uvc in their daily plant maintanace.
But do not ever get your skin exposed to uvc or your retinas / eyes. Small exposure will cause serious sun burn type effects and long term exposures will almost certainly be a trigger for certain cancers.
IMO, some of the anti thrip/ mite stuff that we spray or smoke unknowingly is much more dangerous to us than if we use uvc correctly. And the cleanlight comes complete with uvc filter goggles and gloves.
UVB has no effect on pathogens. You will not get uvc from a mhal bulb of any kind.
Powdery mildew requires around 1800 u watts of uvc to kill the spore. On an 11 watt uvc bulb that means a quick once over with the lamp will kill all spores the light falls on.
Good daily short term use not only kills spores but actually helps the plant to develop thicker leaves which again helps to combat pathogens.
Uvc really is the way forward for desease control.
Here is a copy and paste from another site…
…
Ultraviolt light (UV) occurs from the sun. The wavelength of UV is outside of our visible range. The lowest wavelength colour we can see is violet, hence the name for light with a wavelength lower than this is ultraviolet.
UV ranges from 100 nanometres to 400nm. UV is further divided into UV-A, UV-B and UV-C.
UV-C: ranges from 100nm – 280nm (germicidal)
UV-B: ranges from 280nm- 315nm (sunburn)
UV-A: ranges from 315nm – 400nm (blacklight)
We here are interested in the UV-C rays, also known as „short wave ultraviolet radiation“. UV-C`s germicidal properties have been known since the 1930s. They are used in labratories in order to destroy bacteria, mould and viruses. UV-C rays are able to penetrate the outer membrane of microbes and stop them from reproducing. The specific wavelength of 253,7 nm is known to break the DNA of pathogens.
In May 2007, two Dutch inventors, Arne Aiking and Frank Verheijen were granted an International Patent on a method of treating live plants and mushrooms against pathogens with UV-C light. In the past UV-C had only been used to sterilise things like air and water. The difference with proposing to use UV-C to fight pathogens on living plants is that you shouldn`t use any more than is necessary, otherwise there is a risk to health of the plant.
Mr. Aiking and Verheijens invention is a mobile UV-C lamp that travels up and down in commercial greenhouses. The light intensity of a UV-C germicidal light bulb is usually expressed in a term called „microwatts per square centimetre“. Mr. Aiking and Verheijen suggest a range between 2,500 and 150,000 mircrowatts of UV-C energy over a given 24 hour period.
E.g. A 100 Watt UV-C lamp will output approximately 14,000 microwatts of energy over a square centimetre, in one second, from a distance of two centimetres away. If we leave it there for one minute we have to multiply that figure by 60. (840,000 microwatts). Look at the following chart:
1cm 21,000 µW/cm2 UV output
2cm 14,000 µW/cm²
3cm 10,000 µW/cm²
4cm 8,000 µW/cm²
5cm 6,700 µW/cm²
…
100cm 360 µW/cm²
This shows that a seconds exposure at 1cm distance is roughly equivalent to a full minutes exposure 1 meter away (360 x 60 = 21. 600µW/cm²).
We use the UV-C light to fight against powdery mildew in our plantation. Tests have shown that powdery mildew is killed when given a dose of 1720 µW of UV-C per square cm. For exemple if I took a 100 Watt UV-C lamp and positioned it two centimetres away from the mildew, I would need to switch on the UV-C lamp for just 1/10 of a second to kill it.
Spider mites could possibly also be effectively treated with UV-C but with amounts that are hundreds of times more compared to something like powdery mildew. We therefore use it only against powdery mildew.
The safest way to use UV-C on plants appears to be regular, smaller doses rather than a single, larger hit. We therefore use the UV-C light every day for a short time. The pathogen must be hit directly with the UV-C rays in order to be affected. If it is protected by a leaf, the UV-C will not be effective, because UV-C will not penetrate through leaves.
WARNINGS:
UV-C light has an intense burning effect on human skin and can quickly damage your eyes.
Protect your eyes with special eyeglasses
Dont expose your skin to UV-C rays The wrong amount of UV-C will damage your plant This topic is part of one of our next episodes on FlowerfieldTV. We have just started the treatment of our plants with UV-C rays. At the moment we also use sulphur, because we dont run the risk of getting powdery mildew. After that stage will treat our plants exclusively with UV-C ray. We will regularly report our experiences and tell you our improvements in This thread.
Finally I want to say thank you to Everest Fernandez, who provided a lot of information for this thread.
2 Likes
Glad to see your reference to use of shoe covers. In addition to workers/employees, guests and visitors should put them on as well. Who knows where they’ve been or what is on their shoes?
We were at MJBizCon last month and a lot of people were interested in our automatic shoe cover dispensing system, which makes it faster, easier, safer and cleaner to put shoe covers on. You might want to check the dispensers out here.
Please don’t hesitate to let me know if you have any questions. Happy to help!
1 Like
Glad to see the reference from @casey about using shoe covers. In addition to workers/employees, guests and visitors should put them on as well. Who knows where they’ve been or what is on their shoes?
We were at MJBizCon last month and a lot of people were interested in our automatic shoe cover dispensing system, which makes it faster, easier, safer and cleaner to put shoe covers on. If you’re considering shoe covers instead of or in addition to other methods, you might want to check the dispensers out here.
Please don’t hesitate to let me know if you have any questions, want to see a demo, etc. Happy to help!
3 Likes
Firstly, cleanliness is next to godliness in grow rooms. Clean rooms get pests far less frequently than dirty gardens. Keeping a fresh set of garden scrubs and garden-specific shoes can minimize many issues. I also keep a lab coat in every grow room and always doff accordingly when entering/exiting. Incorporating cleanliness regimens as part of S.O.P. in the facility is always best practice.
In spite of our good intentions, sometimes pests make their way inside our garden…
Although I saw a brief discussion on the subject predatory insects, I’d like to insert a little more info on the subject. When dealing with a large commercial crop, sometimes leaving insect control to nature is the safest strategy. I like non-invasive control strategies. Many growers feel they’ve hit a roadblock when managing some pests and diseases (I know I’ve felt that sense of helplessness while observing a large greenhouse webbed over with spider mites). My favorite means of control is to integrate predators species specifically targeted toward the pest plaguing the garden.
Whitefly and aphid control can be achieved by releasing a species of green lacewing (members of the genus Chrysopidae or Chrysopa). These voracious feeders will proceed to feast on the offending pests affecting your cultivation. They are most effective against juvenile pests.
Spider mite management can be effectively achieved by releasing predator mites. Your climate will most often dictate the species of predator mite to be released. In warmer, more arid climates, my preferred predator mite is Galendromus occidentalis. For cooler or coastal climates I recommend Amblyseius californicus or Phytoseiulus persimeiulus.
When looking for organic or biological pest control, I recommend Arbico Organics. They have a knowledgeable staff and are super helpful. They have a local insectary where they raise predator species and ship worldwide. Definitely worth checking out!
As a side note, grower to grower, do yourself a favor and invest in a good microscope. There’s nothing like watching predators do your dirty work! Roll one up, sit back, relax and watch the carnage happen in real time!
Happy Battling!
1 Like
yes it works now I switched and added Trifecta to my spray the bugs hate it. Spray soil around plants bugs are dying and trying to crawl out but then die. It has thyme oil, clove oil, garlic oil, peppermint oil, corn oil, rosemary oil, citric acid, soap, vinegar… I add neem oil as well
3 Likes
Gary,
This is exactly where I want our operations to be heading.
Thank-you I will certainly be following
2 Likes
build the healthiest grow medium and monitor enviroment. keep air moving and things digesting
3 Likes