What deficiency is this?

L

lilnug420

Well-Known Member
Fem plant

10 Gal pot
Terra canna pro soil
Mega crop fertilizer
Ph adjusted to around 6
About a month away from harvest


I Always get these weird deficiencies in flower, where as in veg they're all nice and green, doesn't seem to affect yield and quality, but im wondering what it is.


Upping the dose of MC hasn't worked in the past so this year I'm sticking to MC calculator reccomentations

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lilnug420 said:
I Always get these weird deficiencies in flower, where as in veg they're all nice and green, doesn't seem to affect yield and quality, but im wondering what it is.
Click to expand...
Very possible that your plants are in a Potassium deficiency stage. The all yellow leaves that I noticed are often a sign of Nitrogen or Potassium shortage and sometimes a shortage of both nutrients.

A Potassium shortage often shows as a yellowing of the tip and then the tips along the serrated edges of the fingers on the leaf. Eventually the edges turn yellow followed by a browning.

Often, as you have noticed, the plants are doing great while in the vegetating stage and then 2 or 3 weeks after flowering starts the problem signs start to show. My belief is that that the plant starts to demand more Nitrogen and Potassium than is available from the soil. Sometimes the grower cuts back on the fertilizers out of concern that the plant will be over fertilized. No matter, the problem starts and once started it can quickly become serious looking. Thing is that increasing the Potassium once the problem shows often does not stop it. But, the added Potassium and often a bit more Nitrogen can slow down the damage which is a win.

I have noticed that if I increase the levels of "flowering" fertilizers starting about 2-3 weeks before flowering starts often delays the signs of deficiency to the last couple of weeks. And, the signs are not as severe as they used to be.

I do not use Mega Crop so can't help with that. There is a Mega Crop thread here so maybe someone has discussed tweaks to the schedule that you might find helpful. It is a couple of years old and kinda long but maybe it will help.

https://www.420magazine.com/community/threads/the-mega-crop-thread.471944/
 
SmokingWings said:
Very possible that your plants are in a Potassium deficiency stage. The all yellow leaves that I noticed are often a sign of Nitrogen or Potassium shortage and sometimes a shortage of both nutrients.

A Potassium shortage often shows as a yellowing of the tip and then the tips along the serrated edges of the fingers on the leaf. Eventually the edges turn yellow followed by a browning.

Often, as you have noticed, the plants are doing great while in the vegetating stage and then 2 or 3 weeks after flowering starts the problem signs start to show. My belief is that that the plant starts to demand more Nitrogen and Potassium than is available from the soil. Sometimes the grower cuts back on the fertilizers out of concern that the plant will be over fertilized. No matter, the problem starts and once started it can quickly become serious looking. Thing is that increasing the Potassium once the problem shows often does not stop it. But, the added Potassium and often a bit more Nitrogen can slow down the damage which is a win.

I have noticed that if I increase the levels of "flowering" fertilizers starting about 2-3 weeks before flowering starts often delays the signs of deficiency to the last couple of weeks. And, the signs are not as severe as they used to be.

I do not use Mega Crop so can't help with that. There is a Mega Crop thread here so maybe someone has discussed tweaks to the schedule that you might find helpful. It is a couple of years old and kinda long but maybe it will help.

https://www.420magazine.com/community/threads/the-mega-crop-thread.471944/
Click to expand...
Last year i did try to up the fertilizer and it didn't help, im worried i will overfertilize, is it possible that it's a lockout or burn?


I can try upping the nutes, but mc is already very high in nitrogen so im Surprised it's a N deficiency
 
lilnug420 said:
I can try upping the nutes, but mc is already very high in nitrogen so im Surprised it's a N deficiency
Click to expand...
It is not necessarily a Nitrogen deficiency because the signs of low Potassium can be similar. Look at both nutrients and try changes in each to see what happens. The plants need more Nitrogen in flower than many realize. It is necessary to the development of all the green plant material that the plant is growing when it grows the flowers.

I give my plants a Nitrogen boost when flowering by adding a liquid fish product to the watering every 10 to 14 days.

A dose of Potassium is easy to do by using a liquid product made with Kelp seaweed. Or top-dressing with finely ground up Kelp Meal product. The Potassium is important to overall plant health and I will add this to the schedule with a 10 to 14 day watering.
 
SmokingWings said:
It is not necessarily a Nitrogen deficiency because the signs of low Potassium can be similar. Look at both nutrients and try changes in each to see what happens. The plants need more Nitrogen in flower than many realize. It is necessary to the development of all the green plant material that the plant is growing when it grows the flowers.

I give my plants a Nitrogen boost when flowering by adding a liquid fish product to the watering every 10 to 14 days.

A dose of Potassium is easy to do by using a liquid product made with Kelp seaweed. Or top-dressing with finely ground up Kelp Meal product. The Potassium is important to overall plant health and I will add this to the schedule with a 10 to 14 day watering.
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Good morning Amigo.
This is basically my first run with MC in the greenhouse & VIVOHUT.
I have found it very high in nitrogen.
If I up the dose in flower I get the deep deep green leaves with the curl.
I dropped back to 1 gram per litre and give a little extra p&k and the girls are very happy.
I love the MC through to about mid flower after that I find it lacking.
Just an observation I've made.
Take care.
Edit BTW. that's coco and I feed every day. :Namaste:

B43E1EAE-22F7-4EB3-A507-29BFF0CAF862.jpeg

B43E1EAE-22F7-4EB3-A507-29BFF0CAF862.jpeg

Miami Miami 10/2/23
@NorthAtlanticSeedCo.
Mc



#VIVOSUN #Love What You Grow
Bill284 😎
 
SmokingWings said:
It is not necessarily a Nitrogen deficiency because the signs of low Potassium can be similar. Look at both nutrients and try changes in each to see what happens. The plants need more Nitrogen in flower than many realize. It is necessary to the development of all the green plant material that the plant is growing when it grows the flowers.

I give my plants a Nitrogen boost when flowering by adding a liquid fish product to the watering every 10 to 14 days.

A dose of Potassium is easy to do by using a liquid product made with Kelp seaweed. Or top-dressing with finely ground up Kelp Meal product. The Potassium is important to overall plant health and I will add this to the schedule with a 10 to 14 day watering.
Click to expand...
Im only running MC, should i try to just up the dose?

So just to confirm this is definitely not lockout or burn?
 
Ok, 10 gallon pot, but how long has she been in it?
The reason I ask is I had problems in flower when using MC for my outdoor plants last year.
It looked like a potassium deficiency, but bumping the MC didn’t help.
I had them in 7 gallon fabric pots, but for a really long time, and it was suggested they were rootbound.
It looks like you're in plastic pots in the pic, so you would get rootbound faster.
 
Melville Hobbes said:
Ok, 10 gallon pot, but how long has she been in it?
The reason I ask is I had problems in flower when using MC for my outdoor plants last year.
It looked like a potassium deficiency, but bumping the MC didn’t help.
I had them in 7 gallon fabric pots, but for a really long time, and it was suggested they were rootbound.
It looks like you're in plastic pots in the pic, so you would get rootbound faster.
Click to expand...
Its fabric pot, definitely not rootbound, i couldn't even fill out a 7gal pot last year
 
Bill284 said:
Good morning Amigo.
This is basically my first run with MC in the greenhouse & VIVOHUT.
I have found it very high in nitrogen.
If I up the dose in flower I get the deep deep green leaves with the curl.
I dropped back to 1 gram per litre and give a little extra p&k and the girls are very happy.
I love the MC through to about mid flower after that I find it lacking.
Just an observation I've made.
Take care.
Edit BTW. that's coco and I feed every day. :Namaste:

B43E1EAE-22F7-4EB3-A507-29BFF0CAF862.jpeg

B43E1EAE-22F7-4EB3-A507-29BFF0CAF862.jpeg

Miami Miami 10/2/23
@NorthAtlanticSeedCo.
Mc



#VIVOSUN #Love What You Grow
Bill284 😎
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Im not getting green curly leaves so should i up the dose? Currently at 6.5g/5L
 
Then I would try raising the MC. It doesn't look like a toxicity to me, and the level you're feeding at is a little less than I'm giving my outdoor plant right now.
On the other hand I'm supplementing it with some magnesium nitrate on the advice of @InTheShed .
 
Missed the edit.
A lot of us were getting issues with yellowing leaves in flower with MC. Shed and some others felt the calcium and potassium were too high leading to imbalances at higher dosages in the latter half of flower.
The magnesium nitrate I'm using helps. As I understand it, raising the ratio of mag to cal, and of N to K brings it back into balance.
My outdoor plant is at 6g/gallon MC, with 1g of mag nitrate.
You can try raising it to 6 or 7g per gallon, or you could go the other way. I know a grower who doesn't go above 4.5g per gallon the entire grow and doesn't get the same issues.
Sorry I'm not much help right now, I'm trying to deal with a situation here, and it's taking up most of my attention.
The last time I had this issue with MC before the mag nitrate I wasn't able to stop it, but the plant got through to harvest, just with a lot of yellowed leaves.
If you're really worried about a lockout the only way to resolve that would be a flush to reset the medium followed by resuming feeding.
 
Just out of curiosity. :Namaste:
My apologies if you said this already.
In soil I feel dry a little water dry a bit feed a little dry water etc.
Is this how your feeding.
I'm using 1 gm per litre of mc and .5 ml per liter of Remo flower.
Girls love it.
Also calmag every feed and a little B1.;)




#VIVOSUN #Love What You Grow
Bill284 😎
 
1.3/L seems low but I mostly grow clones and find them to be a little more hungry than usual, even during veg.
I pretty much feed 1.5/L from start to finish and looking at the MC chart I think that's around where you should be.
I don't really bother going any higher. I rarely add any calmag now as I think I've locked out magnesium because of it. K def seems unusual tbh. Honestly, doesn't help that GL keeps changing their formula.
 
Melville Hobbes said:
Missed the edit.
A lot of us were getting issues with yellowing leaves in flower with MC. Shed and some others felt the calcium and potassium were too high leading to imbalances at higher dosages in the latter half of flower.
The magnesium nitrate I'm using helps. As I understand it, raising the ratio of mag to cal, and of N to K brings it back into balance.
My outdoor plant is at 6g/gallon MC, with 1g of mag nitrate.
You can try raising it to 6 or 7g per gallon, or you could go the other way. I know a grower who doesn't go above 4.5g per gallon the entire grow and doesn't get the same issues.
Sorry I'm not much help right now, I'm trying to deal with a situation here, and it's taking up most of my attention.
The last time I had this issue with MC before the mag nitrate I wasn't able to stop it, but the plant got through to harvest, just with a lot of yellowed leaves.
If you're really worried about a lockout the only way to resolve that would be a flush to reset the medium followed by resuming feeding.
Click to expand...
Im already at around 6g/gal a gal is 3.7 liters ish no? So im pretty close to that at 6.5g/5L

Thing is, the plant next to the one with the issue in the picture, doesn't quite have so much yellowing, i will attach pics, i always have had this issue with MC, i always get to harvest with very nice smoke, but perhaps avoiding all that yellowing would give me even greater smoke.


I did a flush last night, and after watered with a little more than 13g/10L


still unsure what to do next

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