Yellow margins week 5 of flower

[flowrrpowrr]

Several plants developed bright yellow margins in upper leaves during weeks 3-4 of flower. They also have become a paler green and bud development is lagging the others. Their lower leaves (3rd pic) have begun to yellow and develop large brown spots before dying and dropping off. Yikes!!
I flushed with 6.5ph 25ppm rain water three days ago. The runoff tested 6.2ph and 900-1200ppm. Since then one feeding with 6.5ph 265ppm tap water and GH FloraTrio, 2L per plant.
I use the Howweedgrow cheat sheet feed schedule but I skipped CalMag this time.
These plants are 5 gal FFOF and were on Fox Farm trio nutes from about week 5 of Veg. I switched to GH after seeing some symptoms that I thought might be due to salt buildup.
They're under a medicgrow bar6 that's been at 100% since week 3 of flower. Light schedule is 12/12. Temps are 80-83F and 75-78F at night. Humidity is 60-65%.
Wondering if this looks like a lockout of some kind or just simple deficiencies?

 

[bluter]

its a pk ask. more specifically potassium. just need to rebalance the nutes a bit. it's feeding needs have changed now it's in flower.

 

[SmokingWings]

its a pk ask. more specifically potassium. just need to rebalance the nutes a bit.

That is what I was thinking. The yellowing along the edges of leaves in the top of the canopy is usually a sign that some more Phoshorous (P) is needed. And, it is especially a good indicator that more Potassium (K) is needed.

If the yellow color had started showing up in the lower leaves then one of the first things that I think of is that the plant needs a bit more Nitrogen but you mention of "...upper leaves during weeks 3-4 of flower..." points towards the P & K needs. And the timing of 3-4 weeks is pretty much something that commonly shows up based on the similar questions over the years.

Increasing the dose or a re-balancing of the fertilizers should help slow down the change but it often seems that once it starts nothing will stop it and make the leaves go back to their original green color. I look at it this way, slowing it down when there are just 6 to 8 more weeks to go is better than doing nothing and having all the leaves fall off while there are still two more weeks of ripening.

 

[flowrrpowrr]

That is what I was thinking. The yellowing along the edges of leaves in the top of the canopy is usually a sign that some more Phoshorous (P) is needed. And, it is especially a good indicator that more Potassium (K) is needed.

If the yellow color had started showing up in the lower leaves then one of the first things that I think of is that the plant needs a bit more Nitrogen but you mention of "...upper leaves during weeks 3-4 of flower..." points towards the P & K needs. And the timing of 3-4 weeks is pretty much something that commonly shows up based on the similar questions over the years.

Increasing the dose or a re-balancing of the fertilizers should help slow down the change but it often seems that once it starts nothing will stop it and make the leaves go back to their original green color. I look at it this way, slowing it down when there are just 6 to 8 more weeks to go is better than doing nothing and having all the leaves fall off while there are still two more weeks of ripening.

thanks SW. I've upped the GH bloom and micro for P and K and did another feed today. I have been adding some GH Grow (2-1-6) and micro (5-0-1) for nitrogen, so I'm surprised to also be seeing yellowing working up from the bottom as well on most of my plants. Could it be something like excess EC?

 

[SmokingWings]

thanks SW. I've upped the GH bloom and micro for P and K and did another feed today. I have been adding some GH Grow (2-1-6) and micro (5-0-1) for nitrogen, so I'm surprised to also be seeing yellowing working up from the bottom as well on most of my plants. Could it be something like excess EC?

You are well into flowering. The plant is demanding more than it can get. It is highly unlikely that you will make the problem go away. My theory behind working the dose is to slow down the issue and reduce the impact the deficiency has on the plant.

I have been changing my plants over to their flowering feed schedule at about 2 weeks before they get placed in the flowering tent. With the last couple of plants the change over started at the 3 week before flowering mark if the plant was getting large.

And, do you add extra Calcium?

 

[flowrrpowrr]

You are well into flowering. The plant is demanding more than it can get. It is highly unlikely that you will make the problem go away. My theory behind working the dose is to slow down the issue and reduce the impact the deficiency has on the plant.

I have been changing my plants over to their flowering feed schedule at about 2 weeks before they get placed in the flowering tent. With the last couple of plants the change over started at the 3 week before flowering mark if the plant was getting large.

And, do you add extra Calcium?

I have used GH CalMag for most of the feedings. I probably overused it. I misunderstood the feed schedule I'm using and added a tsp/gal. My tap tests between 250-350ppm. I upped my nutes at start of flower. I have a larger group going into flower in a few weeks and I'll start ramping up the nutes earlier.

 

[cbdhemp808]

Hey @flowrrpowrr and welcome to the forum!

Looks like K deficiency, early signs. Red stems and petioles (leaf stems) is another sign of K deficiency, or possibly Mg deficiency, or could also just be genetic. It's been a week since your flush – how are they looking now?

happy growing!

 

[flowrrpowrr]

Thanks for the interest CDBH808.
Not so different really. Still have the yellow margins and pale overall. I've upped the nutes because the yellowing low in the plants is spreading upward at a fast pace. the buds seem very fat and stinky, but the plant seems to be dying from the bottom up. The worst are my Exaltation6. Their bud growth has outpaced everything except the Sherb Breath clones and those 2 strains have the best buds and the worst yellowing.
I'm not seeing yellow margins in the fresh growth, although I don't remember if they it appeared early or later in the affected plants.

 

[cbdhemp808]

It appears you have fed them well during the whole grow, yet they are still going downhill. This makes me think root bound, or some other problem in the roots. I'm guessing plastic pots, not fabric?

Can we see a photo of the whole grow?

 

[SmokingWings]

Not so different really. Still have the yellow margins and pale overall. I've upped the nutes because the yellowing low in the plants is spreading upward at a fast pace. the buds seem very fat and stinky, but the plant seems to be dying from the bottom up. <Snipped>

I'm not seeing yellow margins in the fresh growth, although I don't remember if they it appeared early or later in the affected plants.

Once the plants are into flowering it becomes hard to get ahead of many problems that start to show. And, the further into flowering it becomes even harder.

I have taken to trying to slow down the development of any problems while there is still time before harvest. Then for the next grow I try to get a handle on the problem before it shows up by applying recommended nutrients a few weeks before flowering starts.

 

[flowrrpowrr]

Once the plants are into flowering it becomes hard to get ahead of many problems that start to show. And, the further into flowering it becomes even harder.

I have taken to trying to slow down the development of any problems while there is still time before harvest. Then for the next grow I try to get a handle on the problem before it shows up by applying recommended nutrients a few weeks before flowering starts.

That's my plan with the new plants going into flower soon.

It appears you have fed them well during the whole grow, yet they are still going downhill. This makes me think root bound, or some other problem in the roots. I'm guessing plastic pots, not fabric?

Can we see a photo of the whole grow?

It appears you have fed them well during the whole grow, yet they are still going downhill. This makes me think root bound, or some other problem in the roots. I'm guessing plastic pots, not fabric?

Can we see a photo of the whole grow?

It appears you have fed them well during the whole grow, yet they are still going downhill. This makes me think root bound, or some other problem in the roots. I'm guessing plastic pots, not fabric?

Can we see a photo of the whole gro

 

[flowrrpowrr]

sorry I missed this req earlier. here's a couple from a 2 weeks ago. they're sleeping now so I can't get anything new

 

[flowrrpowrr]

That's my plan with the new plants going into flower soon.

Thanks CBDH. All 5gal fabric FFOF

 

[cbdhemp808]

Looking awesome in those pics. Not so good now??

 

[flowrrpowrr]

fresh pics. 3 4x4's
all under medicgrow bar6 660w
mobile problems now with all but a couple and some minor immobile stuff here and there.
Those seem easy to address and newer growth is better.
The rootbound thing seems likely. They're thirsty every day unless I drench to runoff.

 

[cbdhemp808]

The rootbound thing seems likely. They're thirsty every day unless I drench to runoff.

So, I'm not an indoor grower, so I'm a bit unclear about the ins-and-outs of fertigation in this situation. I know growers use shop vacs to suck up runoff. I see a potential logistical bottleneck for you, because you need to water about 6 plants per tent (?), all by hand – 18 plants? And they all need to get the right amount of nutes, and all need proper wet/dry cycle. Perhaps they are running on the dry side – meaning also insufficient nutes – because you're not (always) drenching to sufficient runoff? With my plants in my greenhouses, I have plenty of space, and it's very easy for me to lift pots a bit to test the weight, and I always water them until lots of runoff, and the runoff just goes into the ground. 5 gal seems a good pot size for the size of your plants, and they are in fabric, so it seems to me now less likely for a root bound issue... I don't know. In terms of some other root issue – i.e. a pathogen – that also seems less likely because many of your plants are affected. Again, I don't know for sure.

 

[flowrrpowrr]

I have 13 flowering in three tents. I only go for runoff when I use ph'd tap. I use
trivets and pans and a shop vac. I've done 3 flushes (2g/plant).
When feeding I use 1.5qt/plant usually 2 day/wk with tap in between.
I had an overheat incident when I went camping and that did a lot of damage. although the yellowing had been a problem earlier.
They spent 12 weeks in veg because of a root aphid infestation.
I'm surprised they've survived all this.

 

[cbdhemp808]

I have 13 flowering in three tents. I only go for runoff when I use ph'd tap. I use
trivets and pans and a shop vac. I've done 3 flushes (2g/plant).
When feeding I use 1.5qt/plant usually 2 day/wk with tap in between.
I had an overheat incident when I went camping and that did a lot of damage. although the yellowing had been a problem earlier.
They spent 12 weeks in veg because of a root aphid infestation.
I'm surprised they've survived all this.

Interesting. So what I do is a bit different... I have high-nutrient custom soil, but I also fertigate when the plants get older (and root balls filling the pot) with a high-N liquid fert NPK 11-2-4. For a 5 or 7 gal pot, I'll fertigate with 2 gal of the mixture of rainwater and the liquid fert. (More or less... 2 gal may be a bit much sometimes for the 5 gal pot. BTW, we are off-grid and only use rainwater.) This way, watering and fertigation are the same thing... fertilizing happens always with watering. I would think with your FF Ocean Forest soil, you would need to fert at every watering, especially when the plants are flowering and need a lot of nutes.

Another possible concern is your tap water. Does it contain chlorine? Do you have a lab test for it? I never deal with having to pH adjust my water, but for you, it seems every watering (fertigation) should be pH adjusted if needed.

RE: root aphids... do you mean fungus gnats (larvae)? I've never heard of root aphids. AFAIK aphids only live on the plant, not in the roots.

 

[SmokingWings]

fresh pics. 3 4x4's
all under medicgrow bar6 660w
mobile problems now with all but a couple and some minor immobile stuff here and there.
Those seem easy to address and newer growth is better.
The rootbound thing seems likely. They're thirsty every day unless I drench to runoff.

The recent set of photos make it look like something drastic has happened in the last two weeks. Now wondering how long it has been since the plants started to show the first signs of flowering stigma/pistil growth.

It is possible the plants have become root bound but that is something that is often already there before they went into flower. If there is a root bound issue then it is very likely that it would be present in most if not all of the plants/pots.

When I see the photos what I notice is that the further away from the front of the grow the greater the wilt in the leaves which is a new problem not related to a need for nutrients like the early photos of the leaf edge indicated.

This wilt is making me think that the plants in the back have not been getting as much water as they should have over the past 4 to 6 weeks. Different reasons why this could be happening. I get the feeling that we are now seeing the accumulated damage to the roots.

This plant does not seem to regrow roots lost to the soil becoming excessively dry even if the dry period is only a day or two every now and then. Once any part of the root system has died from not enough water the plant has to get by on what roots are left. Have had to put up with it myself and about the only thing that could be done was to baby them through till harvest.

 

[Fenderbender]

All I see is another SIP candidate

But yikes that's a shame as those tent contents were looking very nice.
An overheat incident? they sure looked cooked.
I'd do a clean up, get all the real wilted stuff out and keep them going, they indeed have a drive to survive.