My leaves are dying

[jimmyd42]

Hello,

a friend has some trouble with his washington state legal medical marijuana grow 4 weeks into flower. He is growing AK48 sativas.

Its a vertical grow in coco. The leaves that are closest to the lamp (in the plant middle) are turning yellow and then die off.

The Water pH is 5.8 and ec is 1.1.
He uses Canna Coco A+B, pk13/14, boost, cannazym and mag cal.
This is the feeding amounts for 5 gals of water (the guide says 3.5 as he feeds at 0.7 strength) http://i.imgur.com/3nr2f8b.png

The temperature on the leaf canopy is around 30C. The distance from the 1000w hps is around 18 inches.

Here is the journal for the last week:

Here are some pictures (they arent very sharp...)

Why are the leaves turning yellow and die off?

 

[ozzieAI]

leaves tend to die off as the buds mature however those do look a bit over done if only 4 weeks into flower...

okay just read some more...how did your friend flush on the first??? just plain h20 or did he add some nutrient?

 

[jimmyd42]

He "flushed" only with 20% drainage, but several days. He used ph corrected pure water the first time, and after that just a 1.0 ec nutrient solution with 20% drain for a few days.

At first the yellowing stopped and now its coming back a little.

I dont know what is causing this. To me it looks like the pH is off or its over nutrition. I have no idea tbh It would be awesome if someone could have a closer look

 

[ozzieAI]

have you checked here: https://www.icmag.com/ic/showthread.php?t=231387

looks similar to Potassium Deficiency...

however has he checked for root aphids? those buggers can mimic a whole range of nute issues...

hope someone with more coco experience chimes in...i have only just started using it myself...

good luck

 

[jimmyd42]

I checked several guides and couldn't match any of those pictures to my leaves.

Here are some detail pictures:

 

[jimmyd42]

Whats this? Coco?

The main stem

 

[jimmyd42]

The black and brown dots don't move and they dont look like insects. some are long and thin, others are round. I checked both with optical and digital magifiers and it could possibly be coco. Couldn't see any legs, mouths or antennas. He just recently started using coco so im not sure how it looks on the leaves. this could be just some particles, right?

Beneficial fungus? ugh...

Thats quite alot of that beneficial fungus, isnt it? One of the plants looks like this, the others just have some of that fungus. The plant that is affected most doesnt use up its water anymore, so I assume there is a substancial problem in the root zone.

Whats going on here?

 

[jimmyd42]

Frankly, quite disgusting. Is this really supposed to be normal with coco?

 

[jimmyd42]

Here is a closer look at those brown dots

 

[ozzieAI]

The plant that is affected most doesnt use up its water anymore, so I assume there is a substancial problem in the root zone.

check for root aphids or even root rot ASAP...i suffered RA for ages and one sign was that my plants stopped taking up water

also check post #3 in that link i sent through earlier...pics look similar to me...

edit: maybe post a link into the coco forum so someone with more coco experience can chime in

 

[jimmyd42]

How do i check for root aphids or root rot?

 

[jimmyd42]

I dont have any fliers atm. I couldnt say I have seen any insect in a few weeks.

The last time i saw an insect was around 4-6 weeks ago, it looked like fungus gnats or similar (slow, uncoordinated, mosquito-like)

I had fungus gnats a 2-3 months ago, so I didnt really bother when i didnt ever see a flyer again.

 

[ozzieAI]

How do i check for root aphids or root rot?

this is where it can get tricky if your plants a are tied up as you need to remove the pot to inspect the roots, or in the case of rot simply smell the run off water if it stinks you have a problem.

when i RA i had very few flyers and chased nute issues without results. once i inspected the root zone i saw the RA without the use of a loupe and identified them through pics on the net. RA flyers look very similar to FG flyers without a close inspection, and FG and RA can coexist. RA will stunt your growth and reduce your harvest if not dealt with.

as you can see i use PURE neem oil to overcome pests and this may be helpful for you to fully drench the coco regardless of the issue as it has many benefits that assist in dealing with pests as well as conditioning the root zone. drench at least twice, a week after your first allowing the medium to dry out somewhat but not completely between drenches...

prior to me starting recently in coco i was growing in organic soil so this medium is also new to me...

 

[jimmyd42]

Yes, infact the runoff smelled bad, was yellow and had a pH of 7 (which is supposed to be OK in coco)

 

[ozzieAI]

okay then rot is a real PITA as the best way i know to deal with it is to completely remove to roots from the medium via soaking so all the old medium and rotted material is gone and repot into clean fresh coco...scary i know but is the only way i and others i know have been successful in dealing with it

here is a link to guy i helped out last year: https://www.icmag.com/ic/showthread.php?t=266008

regardless of what you do if it is rot you will possibly lose weight in the harvest...

 

[jimmyd42]

ozzie, while we are chatting, I was wondering about your guide. You say u use 5ml/l neem oil

Thats 5ml x 20 liters equals around 100ml in neem oil. Thats around 5 dollars neem oil for 6 plants per week, is that really the correct dosing?

 

[ozzieAI]

yes that is what i use...but i buy it cheaper than you by the looks of it...and make sure it is PURE neem oil not that hydrophobic crap....

but consider that $5 x 8 weeks = $40 for flowering plants = not a bad investment for total (or close to) protection for your plants to ensure a quality harvest...no FG, no RA, no spidermites, healthy plants...i used 12ml/litre to rid myself of RA...

at 5mls you get the systemic action that protects the whole plant, using 2 - 3 mls gives you the dosage for foliar spraying and root conditioning...

it would also knock that fungus you have growing on your medium...

since i have moved to indoor growing i use neem cake in my coco that stops any FG/RA from ever appearing these days and mostly spray to stop mould...but will drench if needed

hope you get your problem sorted nice and quickly

 

[Granger2]

Lay 1" thick slices of potato on top or the medium in each plant. Check bottom side of spud daily for a week or so. If you have RA's they will be attracted to the potato, which is a root crop.

I've never had many fliers. Most of their prolific reproduction is done by pregnant females giving live birth to already pregnant females.

You can tell the diff between RA fliers and Fungus Gnats because the RA has a horned ass. On each side of the rear most part there is a horn like thing.

To fight root rot only, and make no mistake, you CAN overwater coco, Water/feed 4 times with 30 ml of 3% Peroxide/gal. Water, then wait till the weight of the pot/medium is noticeably lighter before you water again. Use a good root stimulator. After the 4th peroxide treatment, reinoculate the medium with EWC ACT or an inoculant product like Great White, Plant Success, or some such product. Do this every week. Use an enzyme product like Hygrozyme. You can increase watering interval as roots re-grow. Foliar is very beneficial while re-growing roots. Good luck. -granger

 

[jimmi420]

He "flushed" only with 20% drainage, but several days. He used ph corrected pure water the first time, and after that just a 1.0 ec nutrient solution with 20% drain for a few days.

At first the yellowing stopped and now its coming back a little.

I dont know what is causing this. To me it looks like the pH is off or its over nutrition. I have no idea tbh It would be awesome if someone could have a closer look

Looks to me like he`s cooking them from overfeeding and salts building in the pots, you supposed to feed to 20% run off each feed and sling that away, to wash out old salts and prevent build up. Without an EC/PPM pen it`s hard to tell, if you had a pen you just check run off and if it starts to climb higher than what you putting in the top you just ease up on feeds, kinda guess work other wise.
Flushing is done by running x2 or 3 water to size of you pots in one go and then straight back on feed or the next day, leeching the medium is what he did og

 

[jimmyd42]

Yeah they cant really be flushed in the tent or moved out.

The runoff has a pH of 7.0 and ppm of 100, the same as the tap water.

I think there were some salt builtups, as you can see in the journal, but that should be flushed out now. They are getting a solution with an ec of 1.0-1.2 since over 2 weeks now.
They previously received nutrients according to the canna guide with ec of over 2.0.
Also the pH was off previously, as the pH meter broke.
At that point leaves started dying after a while and after some feedback from other growers, it was decided that the EC is too high and the pH needs to be in control better.
That was 1.5 weeks ago, but the situation didnt really improve. It didn't continue to get worse at the rate it did before, though.

I just checked the plants and they do have some new dead leaves, some new yellow ones. 1-2 plants seem like they recovered a bit, and the yellowing turned a bit greener.
The others look worse today, the plant that is affected worst is now yellow/green with new dead leaves.

I really dont know what to do here.

What would be a good way to deal with this? Atm I am trying to get the coco dry and then get back to a light feeding schedule with way less water per feeding and more regular feeding.