Something I should worry about? Light green spots, bumpy texture

[GrumpyGrower]

DWC
Nightshade seeds from Barneys
Standard 3 part GH nutes
two 150wt HPS “area” lights
I am using 4 gallon clear plastic totes (covered to block light)
I use one 6wt air pump and two 1 inch airstones per tote
My temps range from 74f to 86f
I use tap water, starts with a PH of 6.8ish, 300ish PPM


Please have a look at this and see if you recognize it.

I FIM topped these young nightshade females, and the new growth since then has been bright green that darkens as the leafs get older, but leaves small light green spots, and the leafs themselves are growing with a bumpy texture. One of the plants is curling up on the edges, but there is no bumpy spotted growth on that one. Meanwhile, the plants continue to grow at a normal rate with no other signs of stress.

The curling

Overall

 

[Roseman]

I 'll take a stab at trying to help.

From the pics, I can tell very little.

In my computer, I built a searchable database about growing pot and I add to it everyday.
I can't diagnois, but I can offer some solutions.
When I search BUMPS and BUMPY growths, I find three possiblities.
1, powerdy mildew beginning. Powdery mildew first appears as small bumps on the top of leaves; soon, the leaves look like they are covered in dusty grit. In some cases, powdery mildew can look like early resin glands.
2, Bumps are also created by the first signs of mites or other insects attacking.
3, Plant Moisture Stress. The plant is too hot, it gets not enough water or not enough oxygen in the water, and the plant is not using the water properly, and and the leaves are reacting to the dryness and curling or cupping.

I suggest you first look for signs of mites. Look for them on the underside of the leaves.
No insects? Then google powdery mildew.
No powerdy mildew? Then Add more airstones so they can drink more water, riase the lights an inch, and google "Marijuna, Moisture Stress" or "Plant Moisture Stress". You will find several good articles written by Uncle Ben.

Leaf Curling?
That one is easier to diagnosis, it is usually over fed, but is accompanied by yellow tips. I don't see any yellow tips, so its NOT over fed, so it is "over heat". If you are using both 150 watt lights now, on those babies, added to seeing leaf curling and bumpy leaves, I'm more sure it is PLANT MOISTURE STRESS.

Plant Moisture Stress is not a great danger, it takes a long time to become a terrible problem, and it can be fixed fast.

1, Raise the lights
2, blow an oscilating fan over them, but not directly on them
3, Cool the room
4, Add a 2nd larger airstone. Get the Dual Whisper two connection AirPump for Aquariums at Walmart
5, Reduce ppm or feedings for a day by half.
6, Raise humidity, roll up face cloths like a cigar, soak them in water and lay them on the tank lid. Hang a soaking wet dripping bath towel or two near them, over a bucket or pan.
7, MIST them if you ruled out Powdery Mildew..

Plants get rained on outdoors and they need it indoors too. But when it rains, it is cloudy and very low light. Turn the lights off, raise them up so they don't get wet. Then soak them good, spray them with pH balanced water, soak them. Let a fan blow over them, but not on them, let them have an hour to enjoy the moisture, then turn the lights back on, and wait an hour to lower them back.

 

[Roseman]

I just remembered, Uncle Ben gave this to me and permission to repost it and use it in my Tutorial and book.


PLANT MOISTURE STRESS - Symptoms and Solutions


Quite often I hear groans from folks having leaf problems -> “Help, my leaves are cupping and the leaf edges are turning brown!”, or, “My plant's leaf tips are curling down and turning black ....what's wrong?” Unless insect damage has occurred or the plant is suffering from a severe case of calcium deficiency, the plant is trying to tell you that it is water stressed. It's hard to tell *exactly* what the culprit is, and unfortunately the “solution” the grower chooses many times is not the right one. A mis-diagnosis only serves to make matters worse by promoting further decline. I’ll try to cover some of the more common causes that can induce these common symptoms and try to offer a few simple solutions. The ultimate and correct solution is in the hands of the grower.

1. 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 plant’s 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 root’s 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.

2. High Heat - the plant is losing water via it’s 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.

3. High Light - yes, it’s true, you can give our faves too much light. Cannabis does not receive full sun from sunrise to sunset in its natural state. It is shaded or given reduced light levels because of adjacent plant material, cloudy conditions, rain, debris and dust collection on the leaf surface, twilight periods of early morning and late afternoon, and light intensity changes caused by a change in the seasons. Too much light mainly serves to bleach out and destroy chlorophyll as opposed to causing leaf cupping, but it often goes hand-in-hand with high heat for indoor growers. Again, back off on the light and concentrate on developing/maintaining an efficient and robust root system. Keep in mind that all but equatorial material receive less light during flowering than during the vegetative stage.

4. Overwatering - this practice only serves to weaken the root system by depriving the roots of proper gas exchange. IOW, the roots are not getting enough oxygen which creates an anerobic condition causing root decline and root rot with the end result showing up as leaf stress, stunted growth, and in severe cases, death. <gasp!> Alot of times folks think the plant is not getting enough plant food (which it can't under such adverse conditions), they add more nutes for a "curative", and just add insult to injury.

5. Underwatering - not only is the plant now stressed due to a low supply of adequate moisture, but carbohydrate production has been greatly compromised (screwed up). Step up the watering frequency, and if need be, organic growers may need to soak the pot from the bottom up until moisture levels reach an even consistency throughout the medium especially with mixes that are heavy in peat. If severe, a little surfactant (liquid Ivory dish soap) added to the drench will help return the organics back to a normal moisture retentive state. If the pot feels light to the lift - it’s time to water. Don’t wait until the soil pulls away from the sides of the pot or leaves droop before you water.
(Contributed by Uncle Ben)

 

[GrumpyGrower]

Thanks Roseman!! Its funny how the answer seems so obvious once someone points directly to it.

I didn't suspect a mite or mildew problem, but I read some articles on them anyway. I don't see any evidence of it.

Uncle Ben's article makes a lot of sense and illustrated for me the situation in my grow room the last few days.

I had moved the plants closer to the light just before these problems started. I suspect even thought I run quite a bit of air through the water, with my small tanks the oxygen was already in short supply, and moving them closer to the light raised the water temps and made the problem worse.

I've put some distance between the plants and the lights and taken measures to keep the tanks cooler.

Thanks again!

 

[Roseman]

and raise the humidity.

Glad I was of some help.

I met Uncle Ben at a different site that he joined in 2001. He left there and came here.
Long time ago, he was a Mod here. He is still on a site I can't mention now. In 2007, He showed me a letter he sent George Cervantes, correcting him and an autographed free book Cervantes sent him back, thanking him. He knows his stuff, but he loves to argue and be DIFFERENT and CONTROVERSAL.

 

[DEAN420]

I just remembered, Uncle Ben gave this to me and permission to repost it and use it in my Tutorial and book.


PLANT MOISTURE STRESS - Symptoms and Solutions


Quite often I hear groans from folks having leaf problems -> "Help, my leaves are cupping and the leaf edges are turning brown!", or, "My plant's leaf tips are curling down and turning black ....what's wrong?" Unless insect damage has occurred or the plant is suffering from a severe case of calcium deficiency, the plant is trying to tell you that it is water stressed. It's hard to tell *exactly* what the culprit is, and unfortunately the "solution" the grower chooses many times is not the right one. A mis-diagnosis only serves to make matters worse by promoting further decline. I'll try to cover some of the more common causes that can induce these common symptoms and try to offer a few simple solutions. The ultimate and correct solution is in the hands of the grower.

1. 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 plant's 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 root's 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.

2. High Heat - the plant is losing water via it's 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.

3. High Light - yes, it's true, you can give our faves too much light. Cannabis does not receive full sun from sunrise to sunset in its natural state. It is shaded or given reduced light levels because of adjacent plant material, cloudy conditions, rain, debris and dust collection on the leaf surface, twilight periods of early morning and late afternoon, and light intensity changes caused by a change in the seasons. Too much light mainly serves to bleach out and destroy chlorophyll as opposed to causing leaf cupping, but it often goes hand-in-hand with high heat for indoor growers. Again, back off on the light and concentrate on developing/maintaining an efficient and robust root system. Keep in mind that all but equatorial material receive less light during flowering than during the vegetative stage.

4. Overwatering - this practice only serves to weaken the root system by depriving the roots of proper gas exchange. IOW, the roots are not getting enough oxygen which creates an anerobic condition causing root decline and root rot with the end result showing up as leaf stress, stunted growth, and in severe cases, death. <gasp!> Alot of times folks think the plant is not getting enough plant food (which it can't under such adverse conditions), they add more nutes for a "curative", and just add insult to injury.

5. Underwatering - not only is the plant now stressed due to a low supply of adequate moisture, but carbohydrate production has been greatly compromised (screwed up). Step up the watering frequency, and if need be, organic growers may need to soak the pot from the bottom up until moisture levels reach an even consistency throughout the medium especially with mixes that are heavy in peat. If severe, a little surfactant (liquid Ivory dish soap) added to the drench will help return the organics back to a normal moisture retentive state. If the pot feels light to the lift - it's time to water. Don't wait until the soil pulls away from the sides of the pot or leaves droop before you water.
(Contributed by Uncle Ben)

I've used UB moisture stress guide and others often, good post Roseman +rep

 

[Roseman]

That Ben is very opinionated, but he knows his stuff.


+REP for you ThatBoyDean.