Potential potassium (K) deficiency during mid flowering? Yellowing tips and edges

[Delty]

Hi all

Strain: White Widow Auto
Light: was grown indoor for veg under LED, been outdoor since week 4
Medium: Coco 7 litre pot
Nutes: Canna A and B
Days: Week 6 / Day 47 (flowered around week 4)

Thanks to some useful information from this forum I am well into my first grow. I seemed to have no issues at all with it until now. I have been feeding it just Canna A and B at around 1.0 EC from the last couple of weeks. We've had some good sunlight here and the plant put on a lot of mass during its stretch and I am finding myself watering it (A and B to 1EC) more frequently. I am testing PH to 5.8-6.0. Yesterday I tested the run off and it was 5.85PH

On one of the feeds about 2 days ago I added a small (2ml to 4 litres) amount of Canna Boost Accelerator to the feed. Some of the very lower leaves receiving little sunlight had started to yellow at this point but I didn't think too much of it. I don't THINK this was connected to my one use of the Boost and I haven't used it since, but over the last 2 days some of the other lower leaves have yellowed and died and some of the tips of the mid height leaves are yellowing.

The leaves are wet in the pictures because it just started to rain heavy so had to cover them.

Is this a K deficiency and if so should I add some Pk13/14? I initially thought it might have been a N deficiency.

Many thanks for your help!

 

[Delty]

Forgot to add photos ....

 

[Mañ'O'Green]

Looks like a touch of potassium and calcium, I would up the EC to 1.4 and I would use some P-K and a bit of Cal-mag.

 

[Delty]

Thank you! That is good to know. I will add those at next feeding and report back

 

[patrickroy33]

On a side note, I'm convinced that theres always going to be some sort of deficiency in outdoor growing. I've accepted it as the new norm. One difference im making this year is staying the path and not over reacting with this nutrient and that nutrient. Overall your plant looks healthy tbh...

A combination of humidity and maybe even high winds can cause a lot of issues too....

In my area it was both this year. But humidity is a killer

 

[Delty]

Yes I was actually very lucky with the move from indoor to outdoor, I was always going to do it toward the end of veg but happened to have perfect weather at that time that matched the tent in climate so the plants took off right away with no adjustment.

Since then there's been periods temps down to 42F, humidity over 85% and right now there are winds that would knock me over. Just as I type this a rainstorm has kicked off.

Plants have now been fed with the addition of some PK and calmag, so hopefully things will heal up. The deficiency had spread a little more when I woke up this morning.

 

[Delty]

So they have now been fed 3 times with the new feed mix: A and B to 1.2EC and 0.5 calmag/litre and just over 1ml Pk13-14/litre.

If there are no other issues I might up the A and B to 1.4EC.

I can still see it has spread very slightly to some higher leaves. How long might it take to see sure signs of recovery?

Thank you again!