Overview of Spectrum Effects on Cannabis Production
Overview of Spectrum Effects on Cannabis Production
Professor DeBacco
Summary
This provides a quick visual and textual summary of the major classifications of spectrums
In addition the main impact on a plant is also provided.
McCree Curve developed in the Late 1960’s - early 1970’s was attempt to understand how plants use light
Interpret with caution as this study was done with multiple points in time data points that was then put into the curve graph
Plants can adjust to their environments, and plants will make the most of the light available to them, which may result in changes in morphology
UV Light (100-400nm) Basics
UV radiation spectrum is divided into three regions called UVA, UVB and UVC.
As sunlight passes through the atmosphere, all UVC and most UVB is absorbed by ozone, water vapor, oxygen and carbon dioxide.
UVA is not filtered as significantly by the atmosphere.
The UV region covers the wavelength range 100-400 nm and is divided into three bands:
UVA (315-400 nm)
UVB (280-315 nm)
UVC (100-280 nm)
The relatively long-wavelength UVA accounts for approximately 95 per cent of the UV radiation reaching the Earth's surface.
With increasing altitude less atmosphere is available to absorb UV radiation. With every 1000 m in altitude, UV levels increase by approximately 10 per cent.
UV Light and Plants Response
UV light responses in plants is similar to blue light
UV light does drive photosynthesis and can also trigger cannabinoid synthesis and potentially reduce disease
UV light does cause some stress to the plants so they may develop thicker leaves and/or protective compounds (ex. Pigmentation such as anthocyanins)
New Look at Old Data
Dr. Bugbee’s lab at Utah State University investigated physicist Keith McCree’s data from the 1970’s in relative photosynthetic efficiency.
Looking at the data the error bars represent the range of plant species from the paper showing small variations among species when grown in the field.
The growth chamber grown plants indicate larger variability.
Is it possible that the field grown plants synthesized compounds to block UV for protection light reducing the effectiveness of those wave lengths?
Blue Photons (430-450nm) and Plant Response
Blue photons reduces cell expansion
Blue photons as a result keep plants shorter and reduce leaf expansion
Notice the morphology difference from growing a cannabis plant under 5% blue vs 20% blue light…
Green Light (500-600nm) Related to Plants
While plants are green indicating there are green wavelengths reflected by the plants this does not mean these are wasted wavelengths.
Green wavelengths of light penetrate deep in the leaf and are absorbed by certain plant pigments which are of benefit to the plant.
Chlorophyll may have reduced absorbance of green wavelengths but this is not the only plant pigment.
Green Photons and Plant Diagnosis
Green photons, as part of white light allows growers to see the plants and better diagnose potential problems
Red Photons (640-700nm) and Plant Response
Red LED’s are among the most efficient at converting electricity into photosynthetic photons and are relatively inexpensive.
Chlorophyll strongly absorbs red light, thus it is effective at photosynthesis.
Many plants grown under only red light (no blue) will have…
A stretched/tall appearance
Thin large leaves large
Far-red (700-800nm) Basics
Far-red light is a range of light at the extreme red end of the visible spectrum, just before infra-red light.
Usually regarded as the region between 700 and 800 nm wavelength, it is dimly visible to human eyes.
Far-Red Light and Plant Response
Far Red is a critical spectrum for plants as it is utilized in the photosynthetic process and can cause an impact on a plants shape
Far-Red is also perceived by the plant photoreceptor phytochrome which is important for light detection (and timing flowing in some plants).
Light Penetration Into Leaf
Notice the difference across the different colors…
Blue vs Far red
Far Red will enhance cell expansion which is essentially the opposite of blue photons
Plants grown indoors with 80 to 90 percent red light and 10 to 20 percent blue light are quite compact, with smaller leaves and shorter stems.
White vs +10% far red
Very important with lettuce with other plants it will cause plants to grow very tall
Summary of Colored Photon Effects
Special Thanks To…
Combination of research data from…
Dr. Bruce Bugbee of Utah State University and Founder of Apogee Instruments Inc.
Shane Torpey MICRO founder
Professor Erik Runkle of Michigan State University
Link to Lecture Slides: drive.google.com/file/d/14Moj...
*Due to the description character limit the full work cited for "Overview of Spectrum Effects on Cannabis Production" can be viewed at... drive.google.com/file/d/1_zVX...
Пікірлер: 30
I think I'm going to write a book and you're my inspiration. I believe I can simplify and teach people how easy or hard this can be. gardening and "tomatoes" have made me a better person
@DeBaccoUniversity
Жыл бұрын
Thanks for the positive comment, best of luck going forward!
Very interesting topic 👍thank you
@DeBaccoUniversity
3 жыл бұрын
Glad to provide quality content!
His uploads are great for a novice/mid level outdoor grower in the Midwest . You warm weather single season state guys have no clue how good ya have it . Yeah I know move it permanently indoors but personally I'll never grow indoors or use hydro setup . Personal preference
@DeBaccoUniversity
2 жыл бұрын
Many different ways to grow covered on this channel!
oh Nice, thanks
@DeBaccoUniversity
2 жыл бұрын
You are welcome!
I love your videos and am learning so much, thank you for putting these up for us. I have a simple suggestion for future videos, could you consider using a "mouse highlight tool" which draws a colored circle around the mouse pointer position to make it easier for us to see your cursor and the information you're highlighting? Thank you, keep up the great work.
@DeBaccoUniversity
3 жыл бұрын
Thanks for the suggestion, I will have to see if this is an option or if it can be added to my recording software.
@QtmMtrlzr
3 жыл бұрын
@@DeBaccoUniversity I use a free tool from the win10 stored called "Mouse Highlight" when I'm doing demo videos for work. Just have to remember to start it before recording each time. Thanks again for the stellar content, looking forward to more videos!
@DeBaccoUniversity
3 жыл бұрын
Thanks for the tip seems like an easy download.
Is it to use a more blue dominant light during veg in order to stack nodes and node density and then use the more red dominant spectra during flower? Looking at something like the Hlg BSpec for veg
@tombryant4518
3 жыл бұрын
Yes. You are correct, and you’ll love the HLG BSpec for veg!
@DeBaccoUniversity
3 жыл бұрын
Your statement is correct, keep in mind it is about the ratio of blue to red and not necessarily just the blue or red output. (Consider the sun.)
What is the dimmer used for if plants like most light?
@DeBaccoUniversity
3 жыл бұрын
This can allow for the intensity to be adjusted easily with out having to move the light, which can be helpful during the early stages of propagation.
Can you tell me why it is most important to keep the plant short and stocky during the veg period? Or is this more so a preference based on your growing space? I can see why as a seedling but once it’s in its veg period I don’t see the other aspects that are beneficial to a short stocky plant 😬 sorry I am a beginner
@DeBaccoUniversity
2 жыл бұрын
Stock Plant = Keep good PAR reading, favor blue spectrum, do not over feed nitrogen fertilizer, maintain good air movement to the point the leaves are moving. Hope this helps.
@crazyjay6331
Жыл бұрын
Been at it a few years and I agree there is no point unless you have limited space, from my experience, using mainly red (660nm) spectrum for veg and flower, works best, you only need to hold roughly 20% blue light for a couple weeks before and during the flip, so the budsites stack closer together. Weed will take all the light you give it so unless your looking for a specific type of growth then supplementing your full spectrum lighting with quality 660nm LED's is the best way to push to really high par values because it's electronically and photosynthetically the most efficient spectrum.
Very informative, it's great to see a résumé like this one about light spectrum! 👍Just one small correction, Shane's company is MIGRO, not MICRO 😉
@DeBaccoUniversity
3 жыл бұрын
Thanks for the correction, missed this at the end, but great to hear the information is appreciated!
My early grow light has both a switch for red and blue..always thought the blue and white were proper for seed to veg...after watching this now I only wanna run the red side...Advanced Leds is the company, well was....
@DeBaccoUniversity
3 жыл бұрын
Reds are efficient for photosynthesis but can increase plant stretching if there is not also blue light provided. When in doubt replicate the suns general spectrum.
Twenty years ago , I ( and by accident ) used HPS & MH at the same time on a crop and pulled 46 Z's from a 5 x5 by 7 (Hydro) , , So.... Then I thought well both " Yes " at the same time ( but ) what if I use secondary times to turn the HPS on & off at keeping the MH on constantly through there day ? WORKED ! And worked to the point were I was thing , ,well🤔 in side I am the creator so... What if I changed other things ? When your sitting around just watching the dam grass grow ,why not mess around , see what you can see ?!? So........... What I did next is looked to see when they would droop or be tired , then I said " what if ........ And it went on & on ... The key is to watch nature , the sun and plants . Now today , well.. Remember we didn't have all these toys to help , we built our lights , tables , and drove illegal clones thousands of miles to be the first in parts of the world , "allegedly" 🌴🤠🌴 Grow On America ,stay free , great guy this Mr. DeBacco Listen up campers ,&' believe !🌴👍🌴
@DeBaccoUniversity
3 жыл бұрын
Thanks for sharing and your praise. Sounds like you were/are implementing the scientific method!
UVA tops out at 380 nm in wavelength, NOT 400 nm.
@DeBaccoUniversity
Жыл бұрын
UVA (315-400 nm) based on www.ncbi.nlm.nih.gov/books/NBK304366/ What source is saying 380nm?