cbdhemp808
Well-Known Member
They didn't use a laser thermometer. They used a FLIR i7 infrared camera. It has an accuracy of ±2°C (3.6°F). Thermal cameras detect infrared wavelengths and display them as a visual image. How do Thermal Cameras Work?
Canoeing leaves
- Thread starter Cheschire
- Start date
cbdhemp808
Well-Known Member
Yep, I think @Delps8 was onto it. See this thread:
Seedling PPFD and DLI? Autos
I'm trying to dial in some numbers for the seedling stage. Weeks 1-2. There seems to be some disagreement as to ideal DLI's. I've heard everything between 12 and 30 for DLI! That is a huge range! What has worked for you?
www.420magazine.com
Also, google: cannabis "light avoidance" praying
Fascinating... first I've heard of light avoidance in cannabis! And first I've seen the word "praying" used, meaning canoeing, cupping, tacoing.
I wrote:
Are we rested on Ca/Mg deficiency? Just Mg?
Side question: Are there any cases where an outdoor grower (greenhouse) would need to worry about VPD?
The “praying” terminology gets so muddled, it’s one of many downfalls of the illegality of cannabis for so long, we don’t have much in the way of hard scientific identifications for specific reactions.
To me canoeing, cupping, and tacoing all refer to a specific look like the one OP posted, or where you’re seeing the serrated edges roll up, whereas praying to me is when the leaf tips are reaching for the light or are raised but flat. Praying is a good sign in my experience, whereas the other descriptions indicate stress, again, in my experience.
I’ve also noticed outdoors you can get a combo of praying and tacoing where the tips are raised but the edges are also raised, almost like the plant is decreasing it’s surface area because of the suns intensity but is still happy. I don’t have a lot of experience outdoors though so I can’t say whether that’s standard or not.
As far as VPD in a greenhouse goes, I can see it being beneficial if you’re a commercial grower going for top of the line performance and profits. VPD being dialed in allows you to push your plants much, much harder, accelerating growth and quality, but it comes at a cost. Regulating VPD in an outdoors environment would be so resource intensive it seems to me it would negate your profits. Although I did read a few articles about using fog to maintain VPD so perhaps it is more feasible than I’m thinking. Regardless, any time you have the ability to control the VPD of your environment efficiently (efficiently being key), you should. It’s the difference between your plant sprinting and walking to the finish line.
cbdhemp808
Well-Known Member
I don’t want to say atypical, because they can look like that.. However, They look like they’re avoiding the light because of other issues and not specifically the intensity of the light. In my experience they will still “pray” and they will also taco up like OPs if it’s related to heat or light intensity.So, are the OP's leaves atypical for light avoidance? They are "up" but also droop:
The red stems are telling me something (I can overlook purple but red is usually a sign), the plant also looks overwatered. I know OP insisted they weren’t but those plants are very clearly swollen in their leaves which is why they have that 3D look, the leaf tissue is literally swelling with water but being constricted by the veins. The overwatering will make it really hard to diagnose most other issues since it can mess with root zone Ph and present itself as tons of other stuff. So between the overwatering and lack of calmag, this plant is not feeling strong at all and isn’t up to the task which is why it’s drooping and canoeing.
I swore I wasn’t overwatering either and my plant looked exactly like this one.. I went out and bought a moisture meter and it turns out I was overwatering.
Here’s one looking like OPs.. it’s overwatered you can tell by the swollen tissue.. it’s also beginning to avoid the light due to magnesium which is messed up because of the overwatering.
Here’s a few more pictures showing avoidance due to mag as well as a nice shot of overwatering and avoidance due to mag looking just like OPs image
cbdhemp808
Well-Known Member
I had a pot that was root bound, water logged, and the plant died from stem rot: here.
Perhaps OP's pots aren't draining well. I see he's got saucers under the pots, but maybe there's water collecting at the bottom of the pots? Maybe would help to drill some side holes at the base of the pots. Or up pot again?
Perhaps OP's pots aren't draining well. I see he's got saucers under the pots, but maybe there's water collecting at the bottom of the pots? Maybe would help to drill some side holes at the base of the pots. Or up pot again?
cbdhemp808
Well-Known Member
Switch to fabric smart pots?
Oof.. yeah that’s rough.. one of my big initial problems was the advice of “stick your finger in the top 2 inches if it’s dry and the pot is light water”.. That quickly lead to some of the images you saw.. Once I read @Emilya Green post about watering a potted plant I decided to get a moisture meter and wait until that sucker read dry all the way until about an inch or two above the bottom. I realized I was watering my plants days before they actually needed it and I didn’t know how light the pot could really get. I had to read her post multiple times to get it to really sink in.
I love fabric pots for sure.. I just looked back at OPs images and I can’t tell what they’ve got. Hopefully the saucers are just there for the room and they’re not letting water sit in them. I did notice some additional yellowing and serrating that looks like mag by way of VPD as well right here.. it’s also why the serrations on some of the leaves look sharp/pointed.
cbdhemp808
Well-Known Member
def plastic. 5 gal. My experience is that fabric drains very well, because the pores in the plastic are too small to get clogged (at least with my grow medium). Also fabric creates a better root structure, whereas plastic causes roots to wind around in the pot. It's all about proper drainage.
Right. I remember others saying to use a wet vac to dispense with the standing water. It's very important to water to the point of getting sufficient run-off.
OK.
i spent years fooling flir. it's how i retained my freedom. flir is easy to fuck up. if you ever had to grow stealth you'd know. flir was used extensively here. to this day all my grow spaces are still set up to keep flir blind to them. most of my friends are the same.
cbdhemp808
Well-Known Member
I believe you, but it really has nothing to do with what we're talking about regarding this test done by Black Dog LED re: leaf surface temperatures. Also, I have no idea why you posted anything about IR laser thermometers.
Delps8
Well-Known Member
Excellent points, all.
Re. praying vs light avoidance - "praying" is up 30° to 45° but I've also seen light avoidance where the leaves go well past 45° and that's where it appears to be light avoidance.
Agree about VPD. For my last grow, VPD was rarely out of range and everything turned out really well.
For the past few weeks, VPD has been 0.8 or lower by sunrise and it takes hours to get to 1.3. My dehu can't get the garage RH much below 45% and the plants are taking up over 2 gallons of water a day so I'm in the "Well, that's just the way it's going to be." mode.
Good call on the degrees, much better description than “up” and “flat” lol.. I agree about the light avoidance exceeding 45.. In my experience the light avoidance shows different ways due to whatever is really driving the avoidance. As we know, Cannabis can take a Godly amount of light as long as you’re observing the cardinal rules (I believe it was actually you who turned me on to Dr Bugbee lol), so any type of light avoidance I’ve seen is usually a direct result of me failing to make sure my environment and resources were balanced for the light intensity.
VPD is a never ending battle if you don’t live in a temperate, average zone during growing months. Obviously we can grow without it, Mother Nature doesn’t usually provide an optimum VPD, and plants still come out as beasts with high quality. However, knowing it by itself is enough to help you adjust your grow.. My situation was similar with the low VPD lingering.. I just made sure air flow was decent in the grow so I could avoid PM and bud rot, and that little adjustment is the difference between losing my crop and harvesting it.
This place has been amazing for the amount of knowledge that gets tossed around in a random thread lol.
cbdhemp808
Well-Known Member
the laser therms are often used to measure leaf surface temp. thought it was originally the tech you were referring to. the camera tech is far more accurate in the lab setting you describe.
cbdhemp808
Well-Known Member
I think both you and @Delps8 were still referring to IR laser thems after I clarified it was a FLIR i7 camera.
Delps8
Well-Known Member
Yeh, Bugbee puts out a lot of good info. That "nine parameters" graphic is very helpful.
Re. light avoidance - that's sort of a fact of life for me because I like to give plants a lot of light. I don't recall leaves tacoing/canoeing. That's a serious issue to me. In contrast, rotating around the petiole or praying at a high angle a temporary reorientation of leaves by the plant and, in my experience, they will resume their normal attitude when light levels drop. I'm getting that a lot ATM — until a day ago (I hope) one of my plants kept on growing in flower and I had to raise the light daily but, some days, a few of the colas grew enough that they got too close to the light. That plant seems to have stopped growing as of this morning (I hope) but I'd guess that there were very upraised leaves every other day or so. PPFD was into the 900's with a 20 hour photoperiod so that's 65± moles. This strain is doing well with DLI the high 50's and low 60's.
Interesting that air flow was the culprit but since that impacts transpiration so heavily and that drive water uptake and that drives nutrient uptake…
Glad you got things figured out.
