Bad Airflow?

Hi,

first of all if i should rather post in Marijuana Plant Problems could someone push me over, thanks.

I have a 1.8 by 3.9 metre room with a height of 1.9 metres.
Temp Day 32°C @ 44% to 50% Night is 21-23 @ 50% - 60%
Light is about 3KW/h less in the morning and evening. CO2 is @ 500-550 ppm

Here is a sketch of the room and the problem that although they are all the same clones Northerlights #5 Haze I have 2 spots where the plants are already yellow and almost ready to harvest and the rest are not yet and the ladies have looked like this since day 35...
A box fan ( 45 Watt ) hangs in all 4 corners and there are also 2 on the floor.
Plus a 50 Watt in Fan and 160 Watt Out Fan.


Room middle
Left side
middle
Right side

unfortunately you can't see it so well on the photos but for some reason some plants mature too quickly, I think it has something to do with the airflow but can't really explain why.


if anything is missing or unclear let me know

Are you growing with LED? I ask because I thought I saw a cob reflector.
Are you sure there's no pollination going on?
When you say day/night temps, I assume you mean the plants light cycle and assume you have lights on while it's dark outside and off when it's warmest outside?
32degrees is hot and your co2 is around ambient levels and you could either reduce temps or up your co2 or both.

What medium, nutrients, ec, pH?

You need to provide closer shots of the problem plants, buds and leaves.

@sunni , can you move the thread over for the OP please.

Also have you checked for bud rot ?
Not enough detail in the pictures to see properly

Yes i work with LED LMB301 in 4000k and 4000k EVO and some older cree cob 3590.

I hope but I can't be 100% sure.
Unfortunately no, I know I have to move towards 25 -30 degrees and increase the CO2 level.

I grow in DWC with Canna Aqua, PH is ~6,2 and EC 1,8 - 2,2

Yes i checked all double, no bud rot( all the same but ), no root rot.
The funny thing is i have the this problem every grow and you can't see it but the yellow buds are from different plants.... and yes all the same clones.

Here is a picture of the air inlet, as well as from underneath. In the last picture I have marked a plant in blue, divided into yellow and green...


2 grows ago I didn't have an air inlet (the black fan), so I suspected that there simply wasn't enough fresh air coming in on the left side. But nothing has changed.

coreywebster said:

Also have you checked for bud rot ?
Not enough detail in the pictures to see properly

Click to expand...

I was gonna say it looks like those "yellow" plants may be rotting/ starting to rot

Assuming your correct and no rot, First thing I'd do is remove those reflectors on your COBs.
They are notorious for focusing too much light .

Looking at your light array I'd say you've got serious hot spots and there may be a correlation to the worse areas.? Hard to tell on my phone.
There's no benefit to using those reflectors in your situation as you'd be better letting that light spread out across more canopy hitting plants from different angles with the overlap instead of being concentrated.

Looks like you are feeding to heavy and possibly missing watering cycles
I agree on lights being to close as well

If using a few different lights a lightmeter might be a good envestment. Was thinking some getting better light than others.