What makes this strange pattern?

[gnarly]

Strain: Unknown (purples on command, though)
Lights: 2x 600w Digital
Area: 4x8' area, 32 plants in 31 pots, 5gal pots
Soil: Fox Farm Ocean Forest, straight up. Hydroton in the bottom for drainage.
Ferts: FF Big Bloom, FF Tiger Bloom, FF Open Sesame, CALMAG Plus

Ok.. Overall the plants are thriving, booming, growing beyond imagination. They love us and we love them. The average is about 18 inches from the soil top, and they average about 18 inches- 20 inches away from the light.

We are completing our 2nd week of 12/12, and our 4th week in the 5gal pots.

Just saw on a few plants, a couple leaves look like this.



Couldn't help but want to ask wtf ya'll think is going on?

It isn't mites, I"m sure of it. I doubt it is any kind of insect since the damage is so even, symmetrical, and systematic looking. bugs are more random.

On the ferts, we have been feeding pretty weak. About a week and a half ago we barely had a very light P burn from Open Sesame, but this last time we fed a bit less paired with a light feed of Tiger Bloom.

Definitely a strange case... Please help.

 

[DocLeaf]

Hi,

It is hard to tell exactly what's going on in your photos. It's NOT mites!

(please use a macro setting)

Looks like caterpillar / grub damage. As shown:



Although holes in the panels like that are characteristic of grubs they usually occur at random. Check the undersides of the leaf-blades daily and remove anything unwanted by hand. The grubs will be in camouflage green!!!

The symmetry indicates some kind of cell problem. Like the plant cells have stretched out, then died with growth.

All the best
peace
dLeaf

 

[DocLeaf]

ALWAYS CHECK PLANTS FROM UNDERNEATH!!!

 

[mjcuresall]

Looks like very early light bleaching. Also looks like a micro deficiency, either molybdenum or boron in particular, but those are rare. (I'm using MynameStitch's guide as a reference.)

 

[gnarly]

I'm actually leaning towards Mg Def. very light...

A lot of the upper leaves are making a kinda V shape that points upward, which i read was characteristic of Mg def. And then I saw some pics and details that described this very event. Chlorosis/necrosis between the veins.

I feed with CalMag, but I feed 1tsp/gallon. Since the 'problem' is very small and only affecting maybe 10 leaves in the whole garden, I'll up it about 30% and see if the problem persists.

And yes, I will check for grubs. I already looked under the leaves, nothing... i keep an NPS strip hanging in there as well.. but Like I was saying, the damage looks way too symmetrical. Looks a lot more plant related than a foreign organism.

keep helping guys... i'm not outta the woods yet!

 

[MynameStitch]

Ya, I think it may be bleaching like mjcuresall has stated. Good call on that Mj!

If you notice the leaves edges are just slightly curling upwards in those last 2 pictures, this means there is some heat related issue going on, weather temps or dry heat from lights being too close and I am betting the lights may be too close if those leaves came from the top part of the plant.
your lights is not even 2 feet away from the plant, so move the lights up a bit, 600 watters produce heat and nice lumens, so raise the light up a little bit.
Where did those leaves come from on the plant? Either way there is some kind of problem related to the light being close, those leaves edges tell all including the slight bleaching it looks like.

 

[gnarly]

i didn't really think it was possible. they are kinda high off the tops of the plants.. not VERY high, but 18 inches at least. And thats just the glass part of the hood. If i put my hand by the plant tops,there very little noticeable heat on my hand... very very little.

Many of the other top/upper leaves have curled upwards slightly as well. Some forming V shapes, and some forming that japanese style house look. But very very lightly/moderately compared to many pics i have seen of successful grows.

The only other factor that has these same traits is light/heat stress, so you may be right. I'll raise the lights up 3 inches or so combined with a bit more calmag on each feeding and we'll see how it adds up.

thanks guys.

 

[mjcuresall]

Ya, I think it may be bleaching like mjcuresall has stated. Good call on that Mj!

Thanks, Stitch. Afterall though, I'm using your info!

i didn't really think it was possible. they are kinda high off the tops of the plants.. not VERY high, but 18 inches at least. And thats just the glass part of the hood. If i put my hand by the plant tops,there very little noticeable heat on my hand... very very little.

It's possible you may have one or more concentrated hot spot(s). If you're using mylar or other reflective material and it's rippled or creased enough, the light may be concentrated in some spots enough to cause heat stress and light bleaching.

 

[gnarly]

thank you so much.. yes we do have mylar and it does have little glinty hotter spots going on.

today we raised the lights 3 inches and also fed about 1.25tsp/gallon.

since the damage is still very light and rare, we are not 'too concerned', but will keep an eye on the hotspots, which will hopefully right itself when we swap to a secret jardin 120x240x120 between now and the next run.

 

[MynameStitch]

Yes, just like mj has said!
Still even if you were using it, you still properly diagnosed it, I have much more progrssed pictures of light bleaching, so you yourself picked it out,you learned from it and that is what what makes people pass it on

Even with a air cooled hood and glass you still can get light bleaching, I had an air cooled one with 1,000 watter and forgot when I was testing it hooking it up, I left it too close to the plant and next day the leaves were bleached!

So it's not actually the heat, but the amount of lumens. Hot spots can happen in form of lumens bouncing off rather than the heat like MJ said.