Concern With Yellowing Of Upper Leaves On Plant In Late Week 4 Of Flowering

MaineGreenery

New Member
So I have three plants that are at the end of the 4th week of flowering. Things have been going fairly well so far but in the past three days I have noticed some yellowing in the interior of some of the upper leaves of a couple of the plants. It is most pronounced on one of the largest plants. I have a picture of the issue below.

8_5_16_center_leaf_issue.jpg


A week or so ago I upped the nutes (FF) from 1/4 to 1/2 strength when I was seeing lower leaves yellowing and thinking I was maybe dealing with a N def. It stopped an issue I had been having with larger leaves at the base dropping but in the past week I have been noticing the yellowing on some upper leaves as shown in the above pic. So yesterday I leeched my plants running 4 gallons of water through each followed by 3 liters of full strength feed.

Also, run-off was tested yesterday during the leeching and came it at about a ph of 6.0.

Do you guys think I am on the right track? Any other thoughts? Being right in the middle of flowering I am worried. This is my first grow but it seems to early to be experiencing normal late flowering yellowing. I am scared of losing the harvest!!!
 
It definitely looks like a non mobile deficiency, being in the upper leaves like that. Several questions if I may...

First, is this soil? if so, what type? Your report of your runoff pH sounds alarming and probably a big indicator as to why you are having the problem. At what pH do you adjust your rez or your incoming fluids to?

Also, at this stage of the grow, nitrogen needs are minimal. Your plant now needs large amounts of phosphorus, potassium and magnesium along with everything else. You should be feeding at full strength, and at the appropriate mixes for this stage of your grow. Do you have the entire Fox Farm nutrient line, the trio plus the 3 solubles? If not, you should get them.
 
Hey thanks for the feedback.

This is a soil grow and the soil is a pretty decent mix of verm, peat and compost in 1/3 each. If you have ever heard of square foot gardening it is the mix recommended in that book. 5 different types of compost in the mix. I don't test ph every time only when I am concerned about an issue. Here is the ph test of the feed mix from a week or two past.

7_29_16_All_PH.jpg


This looks like 6 to me. I thought this was ok for nute absorbtion but am I wrong?

The feed is the ff full line not including the open sesame, beastie and cha ching. After spending on all the others in the schedule I didn't gt those. I figured after working off of just miracle grow for a while that all the ff but those three would be fine. Do you think those other three are crucial? Are those what you refer to as the solubles?
 
Hey thanks for the feedback.

This is a soil grow and the soil is a pretty decent mix of verm, peat and compost in 1/3 each. If you have ever heard of square foot gardening it is the mix recommended in that book. 5 different types of compost in the mix. I don't test ph every time only when I am concerned about an issue. Here is the ph test of the feed mix from a week or two past.



This looks like 6 to me. I thought this was ok for nute absorbtion but am I wrong?

The feed is the ff full line not including the open sesame, beastie and cha ching. After spending on all the others in the schedule I didn't gt those. I figured after working off of just miracle grow for a while that all the ff but those three would be fine. Do you think those other three are crucial? Are those what you refer to as the solubles?
Nutrient_Chart27.gif


The right side of this chart refers to soil grows... and as you can see, 6.0 is out of the usable range of 6.3-6.8 and definitely explains your difficulty. Adjust to 6.5 and it will help a lot.

As long as you are using the tiger bloom and Big BLoom as directed you should be ok, but I do consider the solubles to be essential. Fox Farm expects you to see enough of a benefit from using them that you will buy them again and recommend them, as I am doing here. All the nutrient lines are the same way... you can buy their base products and get one set of results, but if you really want to supercharge things, they provide the products for that too. Those solubles just have a bit more of the essentials that the plants need at each stage, along with some of the micronutrients... it is good stuff, and one purchase of the solubles will last you for a long time.... they go a long long ways.

Lastly, since you are using chelated synthetic nutrients, pH needs to be adjusted as closely as you can to the middle of the soil range. If you are not in that range, your nutes simply do not break down, and you have wasted your time and money by applying them.
 
Thank you! I guess I treat proper PH like a scary disease I might have. I kind of hope for the best because I am afraid dealing with it will be difficult.

Final question. So I watered it Thursday and that is when I noticed this leaf issue. Yesterday, Friday, I leeched and fed again. So my question is, should I wait to refeed with properly ph adjusted solution since the soil has been wet for three days now or should I just refeed immediately?

Also, there are two other plants in this round and neither are showing the same degree of being impacted. Not saying you guys are not right, just wanted to throw that out there in case it affects the diagnosis.
 
Thank you! I guess I treat proper PH like a scary disease I might have. I kind of hope for the best because I am afraid dealing with it will be difficult.

Final question. So I watered it Thursday and that is when I noticed this leaf issue. Yesterday, Friday, I leeched and fed again. So my question is, should I wait to refeed with properly ph adjusted solution since the soil has been wet for three days now or should I just refeed immediately?

Also, there are two other plants in this round and neither are showing the same degree of being impacted. Not saying you guys are not right, just wanted to throw that out there in case it affects the diagnosis.

since lack of nutrition is the major issue right now, treat that first. You are good to be concerned with not letting the plant dry out, and since the problem is only presenting right now on this first plant, I would treat it first, and let the others dry out, only to be properly fed when it is their time to get water.

As to why one plant is presenting with the problem and the others not, many of the non-mobile deficiencies show up first on the most robust plants, and on the sides of those plants getting the most sun. Those plants are working the hardest and therefore need the most nutrition... and when they don't get it, they complain. Trust me, at the pH you have been working with, the others were not far behind in registering their complaints also. You just happened to spot the problem early with your good eye. You got this... you found the problem and the solution early enough that it is not going to hurt much and maybe not even affect the other two plants at all.
 
Oh one other thing because you are just so smart! I know I could go looking for this in the boards so please don't remind me of this; I am just enjoying being educated by someone who knows what they are talking about.

Why are the ph requirements different for hydro vs soil?

...and I noticed in looking at your profile Emilya that you list your occupation as an economist? Is that for real? As an econ major I always appreciate meeting other econ fans.:high-five:
 
Oh one other thing because you are just so smart! I know I could go looking for this in the boards so please don't remind me of this; I am just enjoying being educated by someone who knows what they are talking about.

Why are the ph requirements different for hydro vs soil?

...and I noticed in looking at your profile Emilya that you list your occupation as an economist? Is that for real? As an econ major I always appreciate meeting other econ fans.:high-five:

Thanks MG, appreciate the compliments. Soil has organic components in it that help in the breakdown of the salt bonds that synthetic nutrients are manufactured with, so it is easier to break down the nutrients into the form that the plants can use. Soil also provides a buffering system that can allow for microlife to exist in the rhizosphere, microlife that actually eat organic materials and by digestion break apart the nutrients in the soil. Most soils are manufactured with all of this in mind and with a specific pH drift designed into it so that nutrients have time to react against all of the solids in the soil.

Hydro on the other hand is usually done in pure water, with as few contaminants as possible. There is nothing for the nutrients to react to, they are simply suspended in a water solution. So, in order to allow the plants access to the raw nutrients, we use acid to break down the salt bonds around those molecules and again allow the plants to have access to the nutrients. If we have designed the system correctly, as the nutrients react with the acids and the water, the pH also will drift upwards in a hydro tank, allowing each nutrient to be picked up in its turn.

Since Hydro nutrients need a much more acidic environment to work in, they do not work well at all in a soil container grown, and vice versa.

And yes, I am a real live professional economist and ACFO for a major corporation. I have a PhD in Economics with minors in Political Science and Computer Science. I also have an Associates degree Electronics Engineering and have had an Amateur (Ham) Radio license since I was 14 years old.
 
Is your company hiring? I am thinking of a career change. I used to be a forensic accountant but the past 5 years have been running a property mgmt co. I have the BA in econ, MSA and MBA. I know this is totally ransom but what the hey.
No one is hiring right now, not for good jobs anyway. Everyone is waiting for the end of stagflation and the realization that we have seen clear proof of Ricardian equivalence in this horrible Keynesian experiment that we now call an economy. Looks like you have the management creds though... I would give you a look if your resume crossed my desk at some future date. Keep our company in mind after Trump wins this thing... starts with a big C and ends with an ... (edited... too many clues)
 
Ha ha. I am waiting for everyone to acknowledge that things are simply being artificially held up by crappy monetary and fiscal policy. Bump rates up a bit and this balloon is going to pop! Don't get me wrong, I throw money into the market because I don't want to miss out on the ride, but at the same time I know that a major adjustment is coming. I'm youngish and all about dollar cost averaging. Of course getting more that 4% on my junk bonds would be nice...although I am not excited about the drop in face value that is going to happen.

So about the plants. I followed your advice and refed the affected plant, trying to dial in the solution to 6.5. I don't have a digital meter on my though so I am not super confident that I am really where I need to be. Color matching for ph is tough. I am going to borrow a digital meter this week and fine tune things. If I was able to properly adjust ph how long should the plant take to rebound? I am anxious and want things fixed yesterday...

Thanks!
 
nothing is immediate in the plant world. This is why it is so important to keep those damaged leaves attached so you can see the plant respond to what you do in her time. She should start responding immediately by not getting worse, and then ever slowly color will return. Give her 3 good wet/dry cycles and she will have forgotten all about this. I am sure that some damage will remain from this, but you should see overall color improvement soon.

 
I am checking back in here, things are not all better. Feeling frustrated with the basic ph test kit I had been using which relied on matching colors, I borrowed a digital tester today and got a little more exact. I now have a better idea of what my problem is, but I have no idea how to resolve it.

With the new meter I was able to get my feed water right at 6.5-6.6. My problem is that even though I pumped probably 4 gallons of water at 6.5 through the plant, the run-off at the end was still only at 6.1. Pretty frustrating. I am thinking that maybe it is because of the peat in my soil mix?

Will the fact that I am throwing 6.5 water at it over ride the apparent acidity of my soil? Any other suggestions? I have read about people putting lime as a top dressing but that just doesn't seem like a good idea to me. Going forward I am going to stay away from peat based soils I think and go with coir.
 
I am checking back in here, things are not all better. Feeling frustrated with the basic ph test kit I had been using which relied on matching colors, I borrowed a digital tester today and got a little more exact. I now have a better idea of what my problem is, but I have no idea how to resolve it.

With the new meter I was able to get my feed water right at 6.5-6.6. My problem is that even though I pumped probably 4 gallons of water at 6.5 through the plant, the run-off at the end was still only at 6.1. Pretty frustrating. I am thinking that maybe it is because of the peat in my soil mix?

Will the fact that I am throwing 6.5 water at it over ride the apparent acidity of my soil? Any other suggestions? I have read about people putting lime as a top dressing but that just doesn't seem like a good idea to me. Going forward I am going to stay away from peat based soils I think and go with coir.

Please let me help alleviate your fears. Run off pH has really very little to do with the actual pH of the soil in your container. The water having had just percolated through your entire container has to move the pH a bit, but for us who do not design soil, that pH reading of the runoff is meaningless.

Soil is designed to drift through the pH range. It is usually designed at a higher pH that we typically water at, so that it forces the water in the rootball to drift through the entire usable range of 6.3-6.8. If you come in at 6.5, the peat and stuff in your soil will take it down a few point, which allows you pick up the trace minerals at the low end of the scale. Then as the soil dries out, it approaches its native pH, because of the lime and all the other organic goodies that go into it's makeup, and the pH will drift. This is a good thing, and it was carefully designed into your soil. Putting lime on the top is going to knock this all out of whack. Don't do it. Just water at 6.5 pH every time, and the soil will take care of itself. Forget the run off water. I suck mine up with a turkey baster and flush it.

So, the peat based soil actually is performing a function in your grow, initially taking your pH on a little ride to the low side. Those soil scientists are pretty tricky people.
 
Ok. I have an update. Things do not seem much better but they don't see terribly worse? I have moved into the acceptance phase of this issue and so having now tried about everything I can think of to fix it I am simply going to ride it out. I guess worse case is the plant is doomed but I still have two others that are still looking good. Here is what the issue looks like currently. As always. if anyone has any ideas, thoughts or suggestions throw them at me.

8_12_16_leaf_issue.jpg
 
Im not the best qualified here to offer suggestions but the last pic looks like a k deficiency. At this point they do use alot of potassium.
You said they are not getting worse. You must be on the right track now .. listen to Emilya :thumb: dont over do anything slow and steady they look good!
 
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