Need help identifying nutrient issues outdoor grow..

[OldSquishyGuy]

Hi all...really just my second real season growing outdoors in Portland Oregon and seeing some leaf issues And trying to identify the underlying issue...thx in advance for the help.

We set up 65 gallon smart pots last season and overwintered them....built a super soil recipe, had a good grow last year then remineralized and am using the same pots this year....going organic and have only fed with a fortified worm tea 3 times This season (but we soaked the plants in aerated tea)...worked a bunch of malted barley into the soil (also brewed in our teas) and just topdressed with worm castings and some malted rye. Plants started life as dispensary CLones we did low stress training on for couple of months before they went outside in mid May.

Seeing some leaf discoloration, saw this last year but it didn’t become widespread until late in flower and didn’t really seem to affect bud quality materially so we didn’t do anything about it but give a one time weak application of a fox farms PK booster thinking it was likely a deficiency in one of those nutrients (clearly just guessing)...seeing in only 2 of our 4 legal plants this year, still not too widespread. These two plants got a bit root bound before going outdoors, as did the other two that are doing fine, but they are definitely smaller than their sisters... we bottom water with a drip system that also feeds our vegetable garden which is thriving, weather has been cool but dry all season so no real moisture issues...

https://www.icmag.com/ic/album.php?albumid=81170

 

[OldSquishyGuy]

Didn’t figure out pic post yet but managed to get the pic in my album

https://www.icmag.com/ic/picture.php?albumid=81170&pictureid=1973875

 

[Lost in a SOG]

Phosphorous deficiency.. imo.. the purpling on the leaves is a giveaway..

This is possibly to do with the soil being too cold or the pH being out for decent P uptake at the rate the plant needs due to different properties of the soil. Could also be environmentally induced if the vpd has been out of wack for a while hindering transpiration. Or just low P..

 

[OldSquishyGuy]

Thanks

Thanks

Did a topdressing with a seabird guano...will post how it works. If any other ideas for an organic source that will be available more quickly please let me know.

 

['Boogieman']

What are your temperatures at night?

 

[TanzanianMagic]

Didn’t figure out pic post yet but managed to get the pic in my album

https://www.icmag.com/ic/picture.php?albumid=81170&pictureid=1973875

The purple leaves look like molybdenum deficiency/lockout.

Notice the purple color on the middle leaves, while the plant is in flower:

https://www.sensigarden.com/wp-content/uploads/2017/12/molybdenum-deficiency-cannabis.jpg
Source: https://www.sensigarden.com/molybdenum-deficiency-cannabis/

Molybdenum is one of the trace elements which get locked out at low pH.

So the key is to check the first trickle of runoff for a low pH and a high EC/PPM.

Interesting point:

"Since molybdenum is needed to convert nitrate to ammonia within the plant, feeding with mostly nitrate fertilizer will induce a molybdenum deficiency sooner than feeding with ammoniacal fertilizer."

https://www.pthorticulture.com/en/training-center/role-of-molybdenum-in-plant-culture/​

What nutrients are being used to feed the plants?

And maybe this is the problem:

Worm castings contains minerals such as concentrated nitrates, potassium, magnesium, calcium, and phosphorus.

Source: https://unclejimswormfarm.com/the-effectiveness-of-worm-castings-on-garden-soil-and-plants/
​

So maybe the worm tea is the problem? Too much of the wrong kind of nitrogen, especially during flowering.

I have good expiences using alfalfa pellets in flowering, so maybe an alfalfa tea for late flowering instead of worm tea is an alternative.

 

[Teddybrae]

TanzanianMagic is probably correct ... altho I 'm wondering about Boogieman's question too, because I 've seen low temps cause this.

 

[GOT_BUD?]

The purple leaves look like molybdenum deficiency/lockout.

Notice the purple color on the middle leaves, while the plant is in flower:

https://www.sensigarden.com/wp-content/uploads/2017/12/molybdenum-deficiency-cannabis.jpg
Source: https://www.sensigarden.com/molybdenum-deficiency-cannabis/

Molybdenum is one of the trace elements which get locked out at low pH.

So the key is to check the first trickle of runoff for a low pH and a high EC/PPM.

Interesting point:

"Since molybdenum is needed to convert nitrate to ammonia within the plant, feeding with mostly nitrate fertilizer will induce a molybdenum deficiency sooner than feeding with ammoniacal fertilizer."

https://www.pthorticulture.com/en/training-center/role-of-molybdenum-in-plant-culture/​

What nutrients are being used to feed the plants?

And maybe this is the problem:

Worm castings contains minerals such as concentrated nitrates, potassium, magnesium, calcium, and phosphorus.

Source: https://unclejimswormfarm.com/the-effectiveness-of-worm-castings-on-garden-soil-and-plants/
​

So maybe the worm tea is the problem? Too much of the wrong kind of nitrogen, especially during flowering.

I have good expiences using alfalfa pellets in flowering, so maybe an alfalfa tea for late flowering instead of worm tea is an alternative.

You don't post much.

But what you do post is usually gold.