Diagnosis needed: new growth yellowing, Manganese?

[ChanandlrBong]

Papaya by Nirvana 4 pheno's

White Castle by Nirvana 2 Pheno's


Soil is Fox Farm Ocean Forest with extra perlite.

They have each received one or two feedings of Alaska Fish Fertilizer except for Papaya number 3 (P3).
And, one or two feedings of Fox Farm Big Bloom except for P3.

Water is Ph tap water to 6 - 6.5, its hard water. Ph is close to nine out of the faucet.

Growing under a 400w SonAgro in a 3 x 4.5 Sun Hut.

P3 is unique in that it has not been fertilized and is in a larger, 3 gallon pot. The other 5 plants are in 2 gallon pots.
WC1 and P6 are in 2 gallon smart pots.

WC1 is green but has some leaf tips pointing down at 90 deg angles.
P3 doesn't appear to have any signs of deficiency.

No plants have any N deficiency in old growth.

So, somehow I locked out some immobile nutrient in some of these plants. My guess is Manganese.

front: P5 this one seems to be affected the most back: P3

front: P6 back: P4 back right: WC1

WC2 flushed last night with ph 6

 

[spiderTGO]

Looks to me like your pH is a tad too low. I'd adjust it to 6.3-6.8 in the future instead of 6-6.5. 6 is kind of low for soil. I personally tend to bounce between 6-7 but try to stay around 6.5. Other than that they look pretty healthy!

 

[Dutty Panty]

6.8 and they need nitrogen. I feed nitrogen until week 3 of bloom.

 

[Dutty Panty]

And I'm only referring to new growth. The extra nitrogen early bloom will help down the road. They look pale

 

[ChanandlrBong]

And I'm only referring to new growth. The extra nitrogen early bloom will help down the road. They look pale

I think that is the lighting. The non-chlorotic leaves are dark. Its a SonAgro bulb and a camera flash that makes it look pale. I'll have to update with plain flash pictures. That should help the discoloration to stand out.

 

[Antics]

Leaf tips pointing down is Nitrogen toxicity. Reduce N and that'll clear itself up with time.

Manganese deficiencies will be characterized by new growth being spotted, with yellow/brown areas on new growth. I don't think this is the case here.

The yellowing new growth will most likely be Iron, or Sulfur. These are immobile elements.
Nitrogen deficiencies will show on older growth first, never the new growth. N is a mobile element.

However, the PH you've given us would allow both nutes to be readily absorbed by the plant,, so we have some other problems.

You can also lock these nutrients by using too high levels of some other nutes as you'll see by the second chart below. The first chart shows you the PH at which nutrients are absorbed in soil on the right side. (The left side is for Hydro)

To fix the problem, first make sure your PH meter is calibrated. Use distilled white vinegar (no other type of vinegar will work) and the PH should read 2.4. If it does not, you'll need a new meter for accurate readings.

If your meter is good, make sure your medium is actually 6.5. Test your water. Use PH down until you have the correct reading, it should read 6.5. Water the plant until you have about 10% runoff. Now test the PH of the very first bit of runoff that comes out. It should also read 6.5, or very close to it.

If the runoff is higher than 6.5, this means your soil PH is higher than 6.5, and could be the problem.
If the runoff is lower, or with the 6.5 range, we likely don't have a PH lockout issue, but could be looking at an issue of excess nutrients locking out other nutes, which is shown in that second chart above.

Get those PH tests done and let us know what the results are.

 

[ChanandlrBong]

Leaf tips pointing down is Nitrogen toxicity. Reduce N and that'll clear itself up with time.

Manganese deficiencies will be characterized by new growth being spotted, with yellow/brown areas on new growth. I don't think this is the case here.

The yellowing new growth will most likely be Iron, or Sulfur. These are immobile elements.
Nitrogen deficiencies will show on older growth first, never the new growth. N is a mobile element.

However, the PH you've given us would allow both nutes to be readily absorbed by the plant,, so we have some other problems.

You can also lock these nutrients by using too high levels of some other nutes as you'll see by the second chart below. The first chart shows you the PH at which nutrients are absorbed in soil on the right side. (The left side is for Hydro)

To fix the problem, first make sure your PH meter is calibrated. Use distilled white vinegar (no other type of vinegar will work) and the PH should read 2.4. If it does not, you'll need a new meter for accurate readings.

If your meter is good, make sure your medium is actually 6.5. Test your water. Use PH down until you have the correct reading, it should read 6.5. Water the plant until you have about 10% runoff. Now test the PH of the very first bit of runoff that comes out. It should also read 6.5, or very close to it.

If the runoff is higher than 6.5, this means your soil PH is higher than 6.5, and could be the problem.
If the runoff is lower, or with the 6.5 range, we likely don't have a PH lockout issue, but could be looking at an issue of excess nutrients locking out other nutes, which is shown in that second chart above.

Get those PH tests done and let us know what the results are.

Great thanks, I'll check on those things. I gave one a bit of a micro supplement last night that had iron and sulphur. I'm betting I over-fed on macro's N and/or P. Its my first time using this nutrient. Its really concentrated.

 

[Antics]

I have to ask, did you mix the nutrients with water first?

 

[ChanandlrBong]

I have to ask, did you mix the nutrients with water first?

yup

 

[ChanandlrBong]

Took some better photos away from the HPS


White Castle 2

Papaya 4

Papaya 6

 

[Antics]

Man, I hate to tell you this, but they really don't look bad in those pictures.

I see a slight N deficiency in the first picture (lower leaf yellowed), but otherwise, the lighter green color just appears to be new growth in these pictures.

I would keep a close eye on the new growth for the next couple days, and see if it just starts turning darker to match the old growth.