I need help, I can't figure this one out!

[cbcool]

So a couple of days ago I found some yellow inner fan leaves, I first figured it was due to insufficient light. But the problem has seemed to get worse up to today. I'm finding, older inner fan leaves, with burnt brown tips yellowing then green to the stem. Some seem necrotic, brown crispy, yellow and dead, but just on lower inner leaves near the main stem?

I first thought this was a pH or cal/mag issues, but it is happening to some degree or another on every plant. Then I thought maybe mites of some kind, I've been over them six ways to Sunday with a 100x scope, and found nothing, Im not ruling mites out, but I haven't seem anything.

My next thought was root aphids, I'm currently doing the potatoe test for that, I'll know more in a day or two.

I'm one of those guys who has a pride issue, and it takes a lot for me to ask for help, but i don't want to lose my whole season over pride, so any thoughts tips, advise would be greatly appreciated!?

Also, I'm outdoor, soil was amended with kelp meal, alfalfa meal, humate with molasses, green sand , glacial rock dust, gypsum, disintegrating sulfur, fish bone meal, ewc, stuntzmans chicken compost.

I also have been doing weekly tea, 2lbs alfalfa meal and 1lb kelp meal and 4tlbs agave airated for one week then filtered and added to 400gal tank before watering. Also weekly age old kelp foliar at 1tlbs per gal.

I'm trying to give as much info as possible, then three/four days ago I topped dressed with 2-3 cups of gypsum. I can't think of anything other pertinent information.

The picture of the the whole plant exhibits the worst of the symptoms, but all my plants have a few leaves doing the same thing. Thanks in advance, I'm stumped on this one.

 

[cbcool]

Oh also, I pH my water to 6.5-6.9 with citric acid before I water, and I water about 10-15gal per hole a day. My average hole is 50-60gals, some smaller some bigger, the terrain is pretty rough hear at 38N 5000ft.

 

[corky1968]

I suspect it's a Phosphorus deficiency.

Check this out.

The Complete Guide to Sick Plants, pH and Pest troubles!

 

[cbcool]

Thank you for the reply, I have been through that thread more then a couple times , there are some similar P deficient traits , but there are some Ca , K,Mg, similarities as well thats why I am unsure of what's going on. I did amend with rock phosphate, kelp, and fish bone meal, and tea'd with kelp, so I feel like phosphate deficiency isn't the issue, but I could be wrong as they are switching to flower so o could be wrong.

I don't know it's a good starting point., Thank you.

 

[cbcool]

So I was looking at the same plant pictured above and found a branch tip all shriveled up? Now I'm real confused with what's going on!

Im still pretty new to all this, but I'm learning more every day. Has anyone seen this before?

 

[DarthFader1]

So a couple of days ago I found some yellow inner fan leaves, I first figured it was due to insufficient light. But the problem has seemed to get worse up to today. I'm finding, older inner fan leaves, with burnt brown tips yellowing then green to the stem. Some seem necrotic, brown crispy, yellow and dead, but just on lower inner leaves near the main stem?

I first thought this was a pH or cal/mag issues, but it is happening to some degree or another on every plant. Then I thought maybe mites of some kind, I've been over them six ways to Sunday with a 100x scope, and found nothing, Im not ruling mites out, but I haven't seem anything.

My next thought was root aphids, I'm currently doing the potatoe test for that, I'll know more in a day or two.

I'm one of those guys who has a pride issue, and it takes a lot for me to ask for help, but i don't want to lose my whole season over pride, so any thoughts tips, advise would be greatly appreciated!?

Also, I'm outdoor, soil was amended with kelp meal, alfalfa meal, humate with molasses, green sand , glacial rock dust, gypsum, disintegrating sulfur, fish bone meal, ewc, stuntzmans chicken compost.

I also have been doing weekly tea, 2lbs alfalfa meal and 1lb kelp meal and 4tlbs agave airated for one week then filtered and added to 400gal tank before watering. Also weekly age old kelp foliar at 1tlbs per gal.

I'm trying to give as much info as possible, then three/four days ago I topped dressed with 2-3 cups of gypsum. I can't think of anything other pertinent information.

The picture of the the whole plant exhibits the worst of the symptoms, but all my plants have a few leaves doing the same thing. Thanks in advance, I'm stumped on this one.

Have you checked your soil PH??

Gypsum will make your soil PH take a dive so quickly it will make your head spin!!! As for top dressing with 2-3 cups of this stuff i cannot see how that would do anything except f*** your plants up.

Seriously man, check your soil PH, and make sure you have a quality, calibrated PH pen and your testing methods are sound. Im willing to bet that your soil PH is in the low 5s and is causing lockouts of all kinds.

Hope that helps

P.S If you are adding gypsum for increased sulphur and/or calcium there are much better alternatives but fwiw i would throw that bag of gypsum into the nearest rubbish bin its just terrible terrible stuff for growing weed in. Trust me i had to learn about this the hardway

 

[cbcool]

Hey Darth, thank you for the reply, soil pH is a good point which I've obviously overlooked, but I thought gypsum was a buffer and shouldn't affect the pH that much?

I have an oakton pH 11 handheld, reads upto four Sig figs with point calibration, I did check pH back in the beginning of June and it was 6.62. I use the coleparmer soil pH method.

I added the gypsum for the calcium, plant health on most seem fine, unless this is a precursor to what's going to be a bigger problem?

I will check the pH in the AM and post the results. Do you think the damage to the plant will get worse, I really hope not!?

Thanks again.

 

[cbcool]

I forgot ask, why is gypsum so bad? My father Alway told me it was great for soil, but he only grew vegetables.

 

[corky1968]

Gypsum can be used in gardening. But most people never use it.

Gypsum - The Universal Soil Amendment

 

[cbcool]

Thanks for the link corky, a whole hell of a lot of info in there! What I gathered is gypsum has its place but it needs to be used in a systematic, methodical way, not arbitrarily, witch can cause issues like Darth mentioned if done so like I did.

I'll still run pH tests on several holes tomorrow and hope I didn't fuck up my plants too bad, but if the soil pH did drop due to the gypsum, how do I bring it back up?

On a side note , I got to thinking, I didn't top dress four plants that were in flower, so there may be something to the theory.

 

[cbcool]

The ones in flower aren't exhibiting the same symptoms, forgot to put that part in there.

 

[DarthFader1]

Hey CB,

You are right gypsum does indeed have it's place in gardening, i just wouldn't use it with the weed. There are certain crops that will run great with gypsum but imho i do not believe cannabis is one of them.

The reason i believe it is so bad is because of it's influence on soil PH. Before we get into the nuts & bolts of this dilemma the first thing to do is to ascertain where your soil PH is at right NOW. By "now", i mean take some readings in the AM and get back to us. Try to take a couple of samples so to allow a representative reading.

I'll check back tomorrow and see how you're going.

Best wishes
darth

 

[DarthFader1]

Hey Darth, thank you for the reply, soil pH is a good point which I've obviously overlooked, but I thought gypsum was a buffer and shouldn't affect the pH that much?

I have an oakton pH 11 handheld, reads upto four Sig figs with point calibration, I did check pH back in the beginning of June and it was 6.62. I use the coleparmer soil pH method.

I added the gypsum for the calcium, plant health on most seem fine, unless this is a precursor to what's going to be a bigger problem?

I will check the pH in the AM and post the results. Do you think the damage to the plant will get worse, I really hope not!?

Thanks again.

In my experience gypsum decreases the soil PH even just in the smallest application. It is quite different to dolomite lime but it's important to note that you can easily overdo any kind of lime application and experience lockouts as a result of incorrect soil PH.

 

[DarthFader1]

If you need some peace of mind even with all that gypsum you will still get a harvest, plants will stay reasonably healthy all other things being equal. However you will without a doubt experience a significant drop in yield and quality, but it won't completely ruin everything, just won't be your best work

 

[OgRastaman]

how well did you mix up the soul with the amendments did you top dress and scratch them in it looks to me that your roots might have hit a "hot spot" in the soil where there is a build up of amendments in the soil

 

[corky1968]

I'll still run pH tests on several holes tomorrow and hope I didn't fuck up my plants too bad, but if the soil pH did drop due to the gypsum, how do I bring it back up?

Tiny amounts of hydrated lime (calcium hydroxide) or hydroponic pH up (potassium hydroxide)
will bring your pH up. You'll find these substances at hydroponic stores.

Make sure you apply it to water and test before using it as they can both drive the pH
above 12 in a hurry if your not careful. They are safe to use if you test your pH and go
very slow with them.

 

[cbcool]

Darth, I'm running pH test samples now, I removed soil from four opposing locations, six inches deep, then combined them and coned and quartered until I had a 20g samples. I made sure to remove all rocks and perlite. I'll add 20ml of pH6.74 DI water, stir for 30min on magnetic stirrer, and let settle for one hour then take my readings.

OG, when I amended the soil, I dug it all out on to a tarp and spread out flat, sprinkled on amendments and tuned with shovel. Then rolled it pulling the tarp corner to corner.

Corky, thanks for the info, I'll keep that in mind if I need to bring the pH up.

I'll report back when the tests are done.

 

[Ratzilla]

Ahem I have been using gypsum (calcium sulfate,22% calcium 16% sulfur) in my mix as a buffer for years.
The Sulfate that is in gypsum is considered a neutral salt and has no effect on the mix's ph.
This is also true of K-Mag.
It is only elemental sulfur that lowers pH by acidifying the soil .
Sulfur in the sulfate form does NOT lower it.

"Gypsum contains sulphur as sulphate so will not lower the pH while the calcium that is in gypsum will buffer the mixes ph.
Buffering the pH means making it very hard to move.

I opine that if you start screwing with your pH shit will go down hill very fast especially outside and in flowering.
The pictures look like a N deficiency to me.
So not on the same page at all.
Ratz

 

[cbcool]

Hey rats, thanks for the input, that's the way I always understood gypsum be as well.

I should have pH readings in about 30 mins, so hopefully that will shed some light on what's going on here.

 

[cbcool]

Well I just took the readings from five of my holes, makes a bit more sense why I'm seeing issues, I was on the verge of a serious lockout.

Soil pH readings
Plant pictured above - pH 7.74
Three random holes - pH 7.62, 7.51, 7.78
Flowering not top dressed w/gyp- pH 7.68

I don't think gypsum caused any harm because the plant w/out gypsum is high as well!? I'm unsure what I did or didn't do that caused a rise in the soil pH, I thought for sure they'd be low.

I don't want to start adding a bunch of stuff and cause a drastic pH swing, but leaving it as is wouldn't be good either. My only thought is to pH my water lower to 6-6.2 in hopes that it will temporarily balance out the soil and ride it out for the rest of the season!?

Does anyone have thoughts or input on what would be the best course of action at this point?

Thank you everyone for the help thus far, I do appreciate it.