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Please help me diagnose this plant

Joshau

New Member
Hi I've read the list of cannabis plant problems on ------------ but I can't seem to find a match I don't know whats wrong with my plant can someone help me diagnose this
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Brick Top

New Member
With a boron deficiency, upper cannabis leaves display abnormal and/or slowed growth. Growing tips may not grow properly, may display twisted growth, and may die off. New leaves may wrinkle or curl. Calcium deficiencies also tend to appear on newer growth, which means it first appears on the leaves towards the top of the plant. Did the signs first show up when the lower leaf the picture mainly shows was then new growth, upper growth, or did it show up later and if later where on the plant did it first show signs and if it spread did it spread down or both upwards and downwards?

Knowing those things helps to eliminate certain causes.

"Once you eliminate the impossible, whatever remains, no matter how improbable, must be the truth."

Arthur Conan Doyle, Sr.
 

Joshau

New Member
Hey guys thanks for the advice the oldest growth started showing the purplish black spots at first and then began withering and turning yellow it's been about four days and it's slowly taken over my whole plant and now my other plant is beginning to show similiar symptoms
 

Joshau

New Member
I did a ph test with this cheap ph test kit says it's neutral. 7 or whatever is it supposed to be 6.5 or could it be too high?
 

GroundControl

New Member
New growers biggest mistake made while growing is overwatering the plants.

How often do you water. usings nutes? ph?

need more info.
 

Joshau

New Member
Hey I water in the morning just a bit of tap water that's been left out for 24 hours I didn't feed my plants as they are only three weeks old and I was told that the pro mix HP would have everything they need to get started. However I did start feeding her after she started showing signs of sickness I was hoping it was a simple nitrogen deficiency or something but I've been feeding her for about five days now without any signs of the problem getting any better. I'm feeding her the bio thrive grow at half what the bottle says
 

GroundControl

New Member
If your watering everyday you are probably killing them.
They need oxygen.


I can you see any of the roots?

How wet is the dirt...its got to dry out otherwise they will drown and get root rot and kill her quickly.

I would eliminate that first by checking the roots and how wet is the dirt an inch or 2 down.


I don't grow in dirt (did once and killed it with overwatering).
and have been using hydroponics since...so My knowledge on issues with dirt is limited,
however I see it alot on these forums.
Someone with more knowledge of dirt issues should come along soon.

However it looks exactly like over watering issues that I see on here a lot of the time.
 

Joshau

New Member
So I usually just stick my finger down to the first knuckle and water if it's dry down there here is a pic of my grow room
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this is the typical temp/humidity
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mid day I live in the okanagan it is very dry and hot in the summer
 

Brick Top

New Member
Hey guys thanks for the advice the oldest growth started showing the purplish black spots at first and then began withering and turning yellow it's been about four days and it's slowly taken over my whole plant and now my other plant is beginning to show similiar symptoms

That tells you it's a mobile element problem, almost certainly a deficiency. Mobile elements move both up and down plants and what's happening is an element or elements are in short supply and only moving upwards to the newer growth leaving lower growth with a shortage, a deficiency.

Phosphorus deficiencies exhibit slow growing, weak and stunted plants with dark green or purple pigmentation in older leaves and stems. If a phosphorus deficiency the purpling is caused by an accumulation of anthocyanin pigments. The result is an overall dark green color with a purple, red, or blue tint, and is the common sign of phosphate deficiency. As the deficiency increases the signs spread upwards through the plant or plants.

A phosphorus deficiency will normally show up along the leaf veins and more towards the tip end of the leaf. Not always ar the tips of leaves up around the tip end third or so of the leaves.

Did the purpling occur first along the veins of the leave and more towards the tip end? Did the purpling first show up on the top/upper side of the leaves or on the bottom/underside of the leaves?

If on the underside first than it could be a nitrogen deficiency. Older leaves will grow pale, there will be chlorosis often followed by purpling on the underside of the leaves. What nitrogen the plant has to use is transferred to new growth leaving the older growth lacking.

A phosphorus deficiency is the more likely of the two but now you have to find out the cause, as is there just not enough, are there other elements binding it, is there an overall lockout situation occurring or, while it seems unlikely, are the lights out temperatures dropping to around 50 degrees or below? That is what causes outdoor grown pot to turn purple in the Fall shortly before harvest. At around 50 or cooler phosphorus will not translocate and purpling will occur.
 

Joshau

New Member
First of all thank you for your time. I had originally suspected a phosphorus problem, the purple/black color began at the center of the oldest leaves and radiates out to the tips and after a couple days of this the same leaves began to curl upwards. As soon as I saw this I suspected a nutrient shortage and began feeding them the biothrive. I assumed it wasn't a phosphorus deficiency because I was feeding her daily without any improvement. Is it possible my nutrients are lacking phosphorus and I could use an additive?
 

Brick Top

New Member
First of all thank you for your time. I had originally suspected a phosphorus problem, the purple/black color began at the center of the oldest leaves and radiates out to the tips and after a couple days of this the same leaves began to curl upwards. As soon as I saw this I suspected a nutrient shortage and began feeding them the biothrive. I assumed it wasn't a phosphorus deficiency because I was feeding her daily without any improvement. Is it possible my nutrients are lacking phosphorus and I could use an additive?


What you asked is possible but I don't know how probable it could be.

Cold wet soils, acid or very alkaline soils and compacted soil will add to the problem if the pH is off enough. Phosphorus gets locked out of soil growing at pH levels of 4.0-5.5 Phosphorus is absorbed best in soil at a pH level of 6.0-7.5, though don't go over 7.0, that would only cause other problems. Anything out of the ranges listed will contribute to a phosphorus deficiency.

All these will add phosphorus, but not all at the same rate. Bone meal is a slower/gradual absorption fix. But Making it into a tea speeds up it's absorption rate. Bone/blood meal is also slow acting but again when made into a tea it works faster. Fruit eating bat guano is a fast absorption form of phosphorus. Worm castings fall sort of in between and have a gradual absorption rate. Fish meal is another gradual/medium absorption form to use. Soft Rock Phosphate is similar in it's absorption rate. Jamaican or Indonesian Guano will give you a fast absorption rate. Crabshell is another slow one when it comes to absorption.

If it is phosphorus which it likely is, once you cure your phosphorus deficiency the affected leaves will not show recovery, they will not turn back to healthy green leaves again, but the new growth will appear normal.

Using any of the products I mentioned will mean you will have to keep a close eye on the pH level for a while after using them, or at least depending on what form some of them are used in. Blood Meal, Dried Blood, Guanos, Kelp Meal, Cotton Seed Meal, Peat Moss,
Sulfur and fish meal are all acidic and can bring your pH down, so if you add these be sure to monitor your pH soon after and for a while after.

The same goes with the following, but for the opposite reason or cause they can have. Bone Meal, Rock Phosphate, Wood Ashes pretty much all ashes, Shellfish Compost and Crab Meal are all alkaline and can make your pH go up, so if used, again keep a close eye on your pH or else solving one problem might cause a handful others.

Oh, in the case of Hydro and Soil less Mediums phosphorus gets locked out of Hydro and Soil less Mediums at pH levels of 6.0-8.5.
Phosphorus is absorbed best in Hydro and Soil less Mediums at pH levels of 4.0- 5.8., though I would not suggest going over 6.5. The best range for hydro and soil less mediums is 5.0 to 6.0. If out of the ranges listed it will contribute to a phosphorus Deficiency.

There are other options, some full range/spectrum nutrients and others that are for phosphorus alone and can be found using Google or if you have a good plant and or hydro store nearby one could likely be found. Even though I detest the stuff a half strength mixture of Miracle Grow Tomato Formula has been known to solve a phosphorus problem, but I would look for and pick one of the other options before going that route.

If you want some general knowledge about how phosphorus acts in soils, which means how it will or will not act or work with/for your plants, follow the link and do a little reading. It is not cannabis specific but then like most plant biology it is universal and while things like pH ranges for healthy plants of different types may vary the basics remain the same regardless of if you are growing cannabis, roses or yellow squash plants.

Understanding Phosphorus Behavior in Soils
 

Antics

420 Member
You should really have a way to test the PH of your grow medium, water, nutes, and runoff. Testing PH should also come first when a problem appears, since PH lockout (being too high or too low for a plant to use certain nutrients) will look EXACTLY like that nute deficiency, except the nutes can be available in the soil, it's just the PH is too high, or too low for the plant to absorb them.

And if you assume a deficiency first without checking PH, and if those nutes are already present in the soil, adding more nutes can cause nute burn, or kill the plants.
 

Brick Top

New Member
Something I failed to mention is you might have multiple issues occurring, some that could cause or exacerbate a phosphorus problem.

When it comes to the testing of a growing medium and water all that should occur prior to the start of a grow so you know what you have right from the get go and if any amending or chanced need to be performed. It also gives you a baseline to look back on and see how levels may have or may not have changed as a grow progresses. A pH, EC/TDS, PPM meter is something all growers should have and know how to keep them calibrated and use them often.

It provides you with the opportunity to spot minor fluctuations that if left will occur in problems taking place and give you the opportunity to keep them from occurring or at the very least minimizing any damage and resolving any problems before they reach a critical stage.

To often growers jump to the conclusion a pH problem is behind whatever problems their plants might be occurring when it might be something else. Knowing you are off to a good start and then having that baseline to refer to as regular tests, such as pour though tests are performed, will result in few if any problems and those that might occur being easier to diagnose than posting pictures and asking others to guess the cause when they lack the full data that might be required.

If someone is stumped and asks a question the following, or the answers to as many of the following questions should be given to help others to better help the grower asking the question or questions about a problem or problems.

If growing in soil:

What is your setup, grow room, closet, tent etc.?
How long has this problem been going on?
What strain are you growing?
What was the establishing technique? (seed or clone?)
What is the age of your plants?
How long have they been in the soil mixture they are in now?
Were they in the same mixture when they were seedlings/smaller plant? If not, what mixture were they in before?
How tall are the plants?
What phase of growth are your plants in (seedling, vegetative or flower)?
What technique are you using? (SOG, SCROG etc)
What size pots are you using? (Include how many subjects/plants per pot)
What substrate/medium are you using? What brand of soil mixture are you using?(percentage of perlite, vermiculite...etc?)
What brand Nutrient's are you using?
How much of each nutrient are you using with how much water? Knowing the brand is very helpfu*
How often are you feeding?
If flowering, when did you switch over to using Bloom nutrients?
What order are you mixing your nutrients? (example: veg nutes 1st, bloom 2nd ect)
What is the TDS/EC/PPM of your nutrients used?
What is the pH of the "RUN-OFF"?
How often are you testing pH/ppm/EC/TDS?
What method of pH test was administered? Using Strips? pH pen?
How often are you watering?
When was your last feeding and how often are you feeding?
What type of lighting is being used? (HID, CFL, Plasma, type of bulb, MH, HPS, Ceramic Halide, LED etc.?)
What wattage lighting is being used?
What size bulb are you using?
How old is your bulbs?
What is the distance between the bulb of bulbs the canopy?
What is your RH Factor? (Relative Humidity)
What is the canopy temperature?
What is the temperature in the root zone ares, the temperature near the floor or table the plants are on?
If a basement floor what is it's temperature?
What is the Day/Night Temp? (Include fluctuation range)
What is the current Air Flow? (cfm etc.)
Tell about your ventilation, intake exhaust and when its running and not running ?
Is a fan blowing directly at plants and if so only during lights on period or 24-hours per day or some other length of time?
Is the grow substrate constantly wet or moist?
Is your water hard or soft?
What water are you using? Reverse Osmosis (RO)? Tap? Bottled? Well water? Distilled? Mineral Water?
If using tap water, what is the ppm/EC/TDS of the water right out of the tap?
If using city tap water do you use it right from the tap or let it sit out uncovered for 12 to 24 hours before using it?
If using RO,Distilled,mineral water, what is the ppm/EC/TDS without any additives?
Are you using water from a water softener?
Has plant been recently pruned, cloned or pinched?
Have any pest chemicals been used? If so what and when?
Are plant's infected with pest's?


If growing hydroponically/Aero Ponics/Coco/Soiless:

How long has this problem been going on?
Are you growing in a PVC grow tent?
What system are you running? DWC? Ebb flow? Aero? Water Farm? Flood Tables etc?
What strain are you growing?
What was the establishing technique? (Were the seed or clone?)
What is the age of your plants?
How long have they been in there mixture they are in now?(coco, soiless etc..)
How tall are the plants?
What phase of growth are the plants in? (seedling, vegetative or flower) are the plants in?
What technique are you using?
What substrate/medium are you using?(Hydroton, RockWool etc.)
What is the water temperature?
What color are your roots? White? Brown? Are your roots slimy?
What Nutrient's are you using?
How much of each nutrient are you using with how much water? *Knowing the brand is very helpful*
How often are you feeding?
How often are you giving additional nutrients?
If flowering, when did you switch over to using bloom nutrients?
What order are you mixing your nutrients? (example: veg nutes 1st, bloom 2nd ect)
What is the TDS/EC/PPM you are using
What is the pH of the reservoir
How often are you testing your pH/PPM/EC/TDS?
Are you sure your calibration is correct on your equipment?
When was your last watering?
What is your water temps?
When was your last feeding change? (ie. grow-bloom-micro-additional)
How often do you clean your system: example: Flush out water replace with clean water and nutrients?
What type of lighting is being used? (HID, CFL, Plasma, type of bulb, MH, HPS, Ceramic Halide, LED etc.?)
What wattage lighting is being used?
What size bulb or bulbs are you using?
How old is your bulb or bulbs?
What is the distance between the bulb or bulbs the canopy?
What is your RH Factor(Relative Humidity)?
What is the canopy temperature?
What is the Day/Night Temp? (Include fluctuation range)
What is the current Air Flow? (cfm etc.)
What is your ventilation system, intake exhaust and when its running and not running ?
Is the fan blowing directly at plants? If so for what length of time and if not all the time what length of time and when?
Is your water hard or soft?
What water are you using? Reverse Osmosis (RO)? Tap? Bottled? Well water? Distilled? Mineral Water?
If using tap water, what is the ppm/EC/TDS of the water right out of the tap?
If using RO, Distilled, mineral water, what is the ppm/EC/TDS without any additives?
Are you using water from a water softener?
Has plant been recently pruned, cloned off of or pinched
Have any pest chemicals been used? If so, What and When?
Are plant's infected with pest's

Short vague questions lacking details and pictures, that are often times blurry or very limited and show only where a problem began, the worst part of the plant but not all of it also, do not give someone else nearly all they need to be able to accurately diagnose a problem. Just as with a person with a sickness, a disease, the more information possible, even if some seems extraneous, can make the difference between a quick accurate diagnosis and answer how to resolve the problem or problems rather than the problem or problems becoming critical and possibly to far advanced to save the 'patient' or 'patients' or even do enough to salvage enough of the crop to be worth continue growing the plants.

A physician who specializes in disorders of the brain or nervous system, or even a family physician cannot do much if all they have to rely on is someone saying they are experiencing discomfort or dizziness. A great deal more is needed to be known to quickly and accurately provide help or a cure.
 
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