Need help with yellow margins

[Hempster]

These leaf symptoms don't seem to fit any of the deficiency descriptions I can find. Wondering if anyone knows what this is. Leaves generally look o.k., but middle leaves (not the newest leaves) show sharply yellow margins. Some of them progress to more general yellowing. Some of the oldest leaves go all yellow and necrotic.






some plants look worse than others:

The strain is a mix of trainwreck, super skunk, hash plant, and big bud, growing in a mixture of 22 parts native topsoil, 4.5 parts a complete organic compost/fertilizer product, 2 parts composted manure, 2 parts pro-mix, .5 parts worm castings. Each plant is in a 30 gallon hole. This strain always has the dark red stems and petioles, though maybe not always quite this dark.
pH came out a bit high, for some reason, at 7.3, in a laboratory soil test, and various micronutrients are on the low side, potassium excessive (even though it maybe looks like K deficiency, more than anything else). Are we perhaps looking at a nute deficiency that got corrected, so new leaves aren't yellow-margined? I did dose them all with Miracid a couple of weeks ago, in desperation. I'm trying to figure out what to do, maybe foliar feed with micronutrients, and how to quickly bring down the soil pH.

 

[twiztidbudsmoke]

I did dose them all with Miracid a couple of weeks ago, in desperation

Is that miracle grow or something? At first glance all I cant think is zinc deficiency, I think they are definately missing something

 

[Budley Doright]

Im with you on the potassium....


Next it most closely resemble iron def.....

but that would have to be at the growing points.....


You have plenty of leaves and losing a few wont hurt....


I suggest you monitor..... see if anything is getting worse.....

I dont see anything reminding me of zink def....

 

[twiztidbudsmoke]

I dont see anything reminding me of zink def....

The third and the last pic made me think otherwise, its very close to the tops, could be iron like you said too. Ive seen alot of different looking zinc deficiencies lately, sometimes it looks a little different, heres what stitch says:

Zinc deficiencies on some plants will have the Spotting and bleached spots (chlorosis) between the veins first appears on the older leaves first, and then goes on to the immature leaves. It will then start to slowly affect tips of growing points of the plants. When the zinc deficiency happens so suddenly, the spotting can appear to be the same symptoms to that of an iron and manganese, without the seeing the little leaf symptom.

Fixing your ph is really probabely the answer, it can cause numerous problems

 

[Budley Doright]

I actually know stitch quite well....

she used several of my pics in her sick plants thread....

I would take some of the less frequent defs with a grain of salt....

Im not sure there is anyone who really knows what a zink def looks like in cannabis....
including stitch....


your pictures however are showing marginal chlorosis not interveinal......

 

[Hempster]

your pictures however are showing marginal chlorosis not interveinal......

That's right, it starts out purely marginal.
I was just reading on N deficiency, and it could explain the dark purple stems, and that the older leaves go generally pale and drop. I don't know if it could explain the sharply marginal yellowing on younger leaves, though. Wonder if that could be a response that's unique to the strain. Thanks for all the replies!

 

[Hempster]

So I'm wondering whether to water in some ammonium sulfate to quickly acidify the soil, but is it too late in the season to be putting on much nitrogen? Also thinking of foliar feeding with Earth Juice Microblast, which has all the important micronutrients (except maybe copper?).

 

[igrowkushbitch]

I would guess that your soil is very acidic. I would try get some PH up or some dolomite lime from your garden store. Burnt edges on leaves means there is to much of something in the soil. That is burning your plant. Lack of something would be in the middle of the leaf where the plant is actually drawing nutrients from the leaf. The leaf will turn hard and crumbly. If you used cheap ass soil or cheap nutes thats probably your problem. Best of luck

 

[SupaDupaDupa]

I would guess that your soil is very acidic. I would try get some PH up or some dolomite lime from your garden store. Burnt edges on leaves means there is to much of something in the soil. That is burning your plant. Lack of something would be in the middle of the leaf where the plant is actually drawing nutrients from the leaf. The leaf will turn hard and crumbly. If you used cheap ass soil or cheap nutes thats probably your problem. Best of luck

His Ph is a little on the high side and I don't see any burning, just chlorosis. I wish I had the answer for you, it's probably the higher Ph locking out a micro nute. Best of luck resolving the issue. If you get it resolved could you post what it is and how you fixed it, thanks.