@Farmer_Dan @Growernick
Tough to say, the pictures are kind of grainy. At first glance it looks like a pest issue. Any bug activity under the leaf? You should use magnification when you look.
Second guess would be pH/nutrient problems.
Is this a single plant issue? Are there more like this?
Thank you for your comments. It is only a couple of plants in the room.
I inspected for pests with a magnifying glass and I did not find any.
Is it powdery mildew?
If it isn’t wide spread and all of your plants are treated that same (ie soil, water, nutrients, supplements), I would doubt that is the problem.
What magnification do you inspect with?
Russet and broad mites require 20x minimum. It took me a good 20 minutes to visualize russet mites my first time looking at them. Once my brain understood what I was looking for, they were everywhere…
Are all of the afflicted plants neighbors? If so, I am going with some sort of pest. Fungus isn’t out of the question either.
The leaflets are really varied in colour. From a dark forest green to a burnt colour in only cms…I’m wondering if something is going on in the roots. Nutrient lock? Root rot?
Did this start happening when you flipped to 12/12? How long ago did it start?
No It is not. I did a good inspection.
I use T-H-SEE, which is a very good 40x magnifying glass.
But I will do inspect more carefully again and let you know if I saw anything.
and The plants are not neighbors.
@bryan.eden I think it is a nutrient issue. I believe it starts after we flipped to 12/12 or at least becomes so obvious. I will inspect the roots for root rot. Good point. Thank you!
I was starting to think nutrients as well. Are you using the same nutrients for veg and flower? Same formula?
Yes, early bloom and veg are the same ingredients, different amounts.
Ah, I see. If not neighbors, it probably is a root issue (nutrients, fungus, ph). It is unlikely that pests would start in various places all at once.
Are these hand watered?
How dry does the soil get before watering? Do you think these plants got drier more quickly than others before being fertilized?
One issue with dry soil is if the fertilizer wasn’t used up before they dried out. This will cause fertilizer to crust, then if you fertilize on top of that, the plants will essentially get an overdose.
Just some things to think about.
Great hints. Thank you! Yes, the plants are hand watered. I keep an eye on those plants when watering to learn more about their conditions before and after watering and let you know.
I would flush with distilled water and collect the run off to test pH as a first step. Flushing may help correct any over fertilizing as well and get you back to base line.
What soil do you use? Pre-packaged or hand mixed? Any additives that may not have incorporated equally among all plants?
Do you have a soil test kit? If not, I highly recommend keeping one on hand. I use the LaMotte 5679 kit. 30 ea of N, P, K and pH tests for around $60. I recommend using a scale rather than their scoop for potting soil.
I will do a pH run off on those plants. The soil is pre-packed from supernatural. we do not add any more additives to the soil. For flushing, we use potassium silicate. but almost all plants are happy, except for a couple.
That is a great idea to have a soil test kit. Thank you!
Things happen, at least it is just a few plants, however jumping on the experimental side and making some cause determinations will just give you that much more knowledge and experience.
If you determine pH is off, or get a test kit and see that NPK levels are off, I would check your healthy plants too. Perhaps they are on the verge of a problem? Testing is key.
Looks like lock out to me. Could be PH, over furtilized. What is the ppm of the water? If you flush be sure to reintroduce nutrient solution to avoid shocking the plant. Just a guess. Be sure to let us know if you what you find out.
I did some experiments friends @bryan.eden, @Farmer_Dan, @mdrust:
Inspection for pests, with a 40x magnifying glass with LED and UV lights: No Pests, No PM
ppm and pH run off on both unhappy plants and happy plants: non of them was significantly different between happy and unhappy plants. pH was 6.9 to 7.7 in both groups; ppm was high from 700 to 1400 but surprisingly was high in happy plants too.
@Farmer_Dan unfortunately, I do not have the test kit to mbeasure NPK levels.
Root inspection: Roots were healthy, white color, smell fresh, and no sing of decay.
What you think about virus (TMV), the symptoms are similar to mine. Any thoughts?