Brown spots, distorted growth, in own soil mix

[akasa]

So,

Those plants are from autofem seeds of (nirvana's?) purple kush cbd 1:1. My other plants including chilies etc show some signs but they grow relatively well. This has struck these cbd-bred plants the worst.

So the plants have grow much slower than normal. The brown kills the from the oldest leaves, newest growth has no problems. I used soil that I have from the field (old field been resting for decades, most likely acidic sandy-clay-loam) and mixed in some good amount 18 month aged/composted cow manure, a little dolomite and a pinch of veg fertilizer (about 19-5-20) with S,Cu,Mg,B.

Dont have anything at hand to test anything about the soil.

Actually first time I have problems with plants is here where I live, when using the soil + manure mixture. And I did have growth problems in my field with same combination of soil and manure, with certain plants; expecially chillies had difficulties (though the climate here does not exacly help growing subtripical things @63N22E).

Is it some elemental deficiency that could bother the soiltype (last year i used total fertilizer with no problem, but with less manure though it was much more fresh, the same pile i take from now also a year later). Or coul it be the manure, that i suspected causing problems last year also, perhaps some chemical in it or ammonia burn etc?

Any thoughs about the leaf damage?

I though that the deformities of leaves is due to inbreeding to get high cbd-content... And btw these autoflowers started flowering now about at four-five weeks of age.

with thanks,

AK

 

[pute]

Calcium deficiency..What is your pH and are you giving then cal/mag?

 

[akasa]

I added powdered garden lime when mixing the soil, has 5%mg in it. Embarassingly I have (never had) no ph meters or any other fancy tools, just been growing. I just now took from the pot a good big spooful of soil, mixed it in a cup of water and measured with aquarium ph strip which give something around 6-6.5, though I dont know how soil behaves in water like that... But yea, will get some proper ph-test.

 

[pute]

If your pH is 6.5 then you have a serious calcium deficiency in my opinion. Until you give it cal/mag it will continue to get worse. The leaves that are already infected will not get better.

 

[leafminer]

In my opinion you should pay a lot more attention to your soil mix. Field soil + manure, it's probably going to be very acidic, very nitrogen heavy. You need to lighten it up. Try replacing 25% with peat, 10% with Perlite. Don't use much manure. Use a balanced fertiliser instead.

 

[pute]

I agree as well. I really didn't look at you soil just saw the leaves but Leafminer is right. Use decent soil. I use peat and Perlite only. Nothing in it. That way I know exactly what they are getting as far as nutes/sups.

 

[WeedHopper]

Be careful with manures. They are hot and full of nitrogen. A little goes along way.

 

[akasa]

Thanks for replies. This past grow projects have being "in the forest with what you have" thus the own soil. I am sure you are all right about the manure and acidicity.

About the plants, I have first flushed them and then watered with with teaspoon of CaOH in 4 litres of water. The brown spot problem has disappeared and growth started, but the seeds being autoflower, they have already started flowering early on, and it seems clear that the crop is all but lost. A bucket of balanced flowering fertilizer is at hand now.