Plant Moisture Stress - Symptoms and Solutions
- Thread starter Uncle Ben
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bender420
Well-Known Member
This was very helpful. I have never read this before, and it really helped me determine the problem I have.
Thank You.
Uncle Ben
Well-Known Member
Yep, think outside of the box. Most folks give their plants exactly the opposite of what they need for optimum growth. After the "you can't give a plant too much light" paradigm comes the usual drill of giving their plants more light during flowering, bass ackwards of what actually happens in nature. Other than purely equatorial genotypes, cannabis gets far less light during flowering than during its vegetative phase.
Bottom line? Find the point of light saturation for your plant and maintain light levels just below that point. For me, using the typical forum crude and inaccurate watts/s.f. drill, it would be about 33w/s.f. based on my light setup which is gonna be different than the next guy's.
Back during the days of ADPC and then CW and OG, the "kewl folk" would brag about attaining light levels of 100W/s.f., as if it would increase production (which it won't). It was nothing more than inexperienced noob talk, stoner macho chest beating. Not only is that ridiculous regarding plant requirements, it's rather silly regarding "buying light".....very inefficient and wasteful.
"As light intensity is increased, eventually an intensity is reached above which light no longer is the factor limiting the overall rate of photosynthesis. We say that a process is 'saturated' for a particular reactant when adding more of it does not increase the rate, just as a sponge becomes saturated with water when it can't hold any more. At the light saturation point, increasing the light no longer causes an increase in photosynthesis."
http://www.marietta.edu/~spilatrs/biol103/photolab/saturati.html
The only way you can increase photosynthesis with light levels above a plant's light saturation point is with an increase in CO2.
Good luck,
UB
Hola Tio Bendejo!
I need a no bullshit answer on something and I know you're just the guy to give me one!
In the flowering room, how dark does it have to be? My light cycle is from 9pm to 9am....in order to deal with the high daytime temps we've been having, along with the low nighttime temps.
There are no direct leaks of light, but the ducting from the fans "glows" just a little. Not enough to read by, but a lot like a dark night, where you can see a bit.
My theory is that outdoors it's not pitchblack all the time, and at times can be quite bright with the moon, etc.
Other people say, "one flash of light and you've got hermies," or "if it's not pitch black your plants won't flower," etc.
So, can you help me out here bro?
I need a no bullshit answer on something and I know you're just the guy to give me one!
In the flowering room, how dark does it have to be? My light cycle is from 9pm to 9am....in order to deal with the high daytime temps we've been having, along with the low nighttime temps.
There are no direct leaks of light, but the ducting from the fans "glows" just a little. Not enough to read by, but a lot like a dark night, where you can see a bit.
My theory is that outdoors it's not pitchblack all the time, and at times can be quite bright with the moon, etc.
Other people say, "one flash of light and you've got hermies," or "if it's not pitch black your plants won't flower," etc.
So, can you help me out here bro?
Roland
Active Member
hahaha ... I had someone tell me the same thing ... 1 pinhole makes hermies ....... I don't think that's what makes hermies ....
I'm trying to force a female into making "pollen sacks" now ! it's been sitting in daylight all day and a HPS street light all night for three months ..in flower stage ......... no hermie yet ......... and btw under near 12 hr full moon cycles too ....if does make male pollen sacks .... I'll let u know
I'm trying to force a female into making "pollen sacks" now ! it's been sitting in daylight all day and a HPS street light all night for three months ..in flower stage ......... no hermie yet ......... and btw under near 12 hr full moon cycles too ....if does make male pollen sacks .... I'll let u know
Uncle Ben
Well-Known Member
Hola! Yeah, like Roland said, I wouldn't worry about it.
Interesting! I just addressed the two products here: https://www.rollitup.org/indoor-growing/230302-10-000-watt-grow-29.html
It's great that you're doing a comparison.
Good luck,
UB
Over-fertilizing - the most common cause of leaf cupping aka leaf margin rolling, leaf margin burn, and leaf tip curl/burn is the overzealous use of too much plant food in relationship to factors such as plant size, vigor and rate of growth. The first unit of a plant to show moisture stress is the leaf at its margins and/or tips, reflected by margin rolling (cupping) or burning. Sometimes copper colored necrotic spots show in the leaf also. A hard, crispy feel to the leaf frequently occurs as well, as opposed to a soft and cool feel of a happy leaf. When you have a high concentration of salts in solution (or in the root medium) compared to lower salinity levels found in the plants tissue, water is actually drawn out of the plant across the root gradient in order to fix the ppm imbalance. IOW, this is a natural, osmotic response that serves to equalize salinity levels on both sides of the roots epidermal gradient. Back off on the amount and/or frequency of plant food. Too much plant food can also burn the roots, especially the sensitive root tips and hairs, which then creates another set of problems such as nutrient deficiencies. A note for the bio folks - as soil dries, the concentration of the remaining salts rises further exacerbating the problem. Leach (flush) your pots once in a while to get rid of excess salts.
High Heat - the plant is losing water via its leaves faster than what can be replaced by the root system. The leaf responds by leaf margin cupping or rolling (up or down) in order to conserve moisture. A good example is reflected by the appearance of broad-bladed turf grass on a hot summer day, high noon, with low soil moisture levels - the leaf blade will roll in and the grass will take on a dull, greyish-green appearance. Upon sunrise when moisture levels have returned to normal, the leaf blade will be flat. Lower the heat and concentrate on developing a large, robust root system by practicing sound plant culture. An efficient and effective root system will go a long way to prevent heat induced leaf dessication and leaf margin curling by supplying sufficient moisture for good plant health. One short episode of high heat is enough to permanently destroy leaf tissue and cause a general decline in the leaves affected, which often occurs to leaves found at the top of the plant located near HID lamps. The damaged leaf (usually) does not recover, no matter what you do. Bummer in the summer. One can only look to new growth for indications that the problem has been corrected.
High Heat - the plant is losing water via its leaves faster than what can be replaced by the root system. The leaf responds by leaf margin cupping or rolling (up or down) in order to conserve moisture. A good example is reflected by the appearance of broad-bladed turf grass on a hot summer day, high noon, with low soil moisture levels - the leaf blade will roll in and the grass will take on a dull, greyish-green appearance. Upon sunrise when moisture levels have returned to normal, the leaf blade will be flat. Lower the heat and concentrate on developing a large, robust root system by practicing sound plant culture. An efficient and effective root system will go a long way to prevent heat induced leaf dessication and leaf margin curling by supplying sufficient moisture for good plant health. One short episode of high heat is enough to permanently destroy leaf tissue and cause a general decline in the leaves affected, which often occurs to leaves found at the top of the plant located near HID lamps. The damaged leaf (usually) does not recover, no matter what you do. Bummer in the summer. One can only look to new growth for indications that the problem has been corrected.
Yo Uncle Ben I got a quick question. This is my first grow and i have a solid seedling going right now, it is about 5 days old. If you can see in the pic the tips of the razor leaves seem to be rolling under the leaf. I suspect it is a watering issue, but I am not sure if it is too much or too little water. Thanks for the help.
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GibsonIconoclast
Active Member
Just a quick question... should I be very worried if i've lost 6 lower main fan leaves to nitrogen deficiency in my first 3 weeks of flowering?
I'm using Oneness by Humboldt nutrients, 5-9-4
I'm using Oneness by Humboldt nutrients, 5-9-4
hey ub,
just an update on the micrkote vs. the smartpots. so far the container w/ the micrkote is almost a quarter size bigger than the smart pots. even though the smart pots dry out faster they are not as healthy as the mk pot. interesting.
been try'n to follow your advice with all my fuckups. been chang'n alot of my bad habits and try'n to read the plants. but one question. if the new leafs during early budding are starting to cup downward and slow down on growth but showing no signs of tip burn or leaf tips pointing down what would that be. what shows first w/ overfeeding, tip burn or leaf cupping? having a hard time reading plants if they are overfed or underfed. i am feeding way less than my overfeeding days but wondering if too much. thanks.
just an update on the micrkote vs. the smartpots. so far the container w/ the micrkote is almost a quarter size bigger than the smart pots. even though the smart pots dry out faster they are not as healthy as the mk pot. interesting.
been try'n to follow your advice with all my fuckups. been chang'n alot of my bad habits and try'n to read the plants. but one question. if the new leafs during early budding are starting to cup downward and slow down on growth but showing no signs of tip burn or leaf tips pointing down what would that be. what shows first w/ overfeeding, tip burn or leaf cupping? having a hard time reading plants if they are overfed or underfed. i am feeding way less than my overfeeding days but wondering if too much. thanks.
Uncle Ben
Well-Known Member
I wouldn't lose any sleep over it but the fewer the healthy fan leaves retained, the less the production. If the 5-9-4 is not sustaining healthy leaves, then you need to switch to a food that will, like a 20-20-20, 9-3-6, 7-3-3 etc. It's a no brainer, once you wean yourself off the forum paradigms and cute labels and return to the basics - botany.
UB
Uncle Ben
Well-Known Member
That is interesting. Thanks for the update.
It can be a heat event. Has happened to me often and once it does, it never rights itself.
This isn't gonna help much, but it's really your call regarding trying to balance all cultural factors. If your plants are bulking up rapidly like during the stretch, then needless to say they are gonna require more food. I use that word alot, cause that's what it's all about - giving your plants what they require but also knowing when you've reached the saturation point where "more is less". Most problems are grower related, folks try to push their plants in hopes of getting more production which always leads to less due to the "aw shit" factor encountered. I've been growing all kinds of plant material for decades and it never ceases to amaze me how fast something can grow WITHOUT my help regarding foods. Of course I do organics and they can go a long way. Some of my best yields have been by using a soil rich in organic foods which usually produces really well from start to finish without any additional salts (fertilizer).
Stay free,
UB
DamnJailBird
Member
what do i do inorder to make my plant bush up? its only 5wks old
pimporplayer101
Member
aye uncle ben. would u happen to be living in the bay area ? i think i've met you before with my friend tai back then. i dunno if its the same mr. ben. hahah. just curious.
Uncle Ben
Well-Known Member
Tell your friend Tai that Uncle Ben's fluffs up mo betta.
goldilocks007
Member
hi my leaves have turned yellow and black on thea edges 3wks into flower and realised i had gone over 12/12 and not turned my extractor over to 24hr could this have caused the problem
thanks
very worried mother
thanks
very worried mother
all4one1fourall
Member
UB: Excellent stuff. I like the " just the basics" approach and "less is more". Too many people get lost in the mechanics of growing when they sould just let it grow and be patient, and learn to enjoy the ride.
Uncle Ben
Well-Known Member
Too many people get caught up in the vendor hype, forum mystique and romanticism. It's a weed.....don't screw it up with alot of crap it doesn't want or require.
UB
pimporplayer101
Member
haha so your the same mr ben.? because he lost contact with you he was tryna reach you.