Alright, so I have been trying to figure this out,reading through posts and deficiency guides, but still unsure. It plagued me on my last grow, but only on my "headband" plants and again on one of my current grows, but still only on the "headband". I thought it might be a magnesium def. but I'm really not sure.
Have you tried mixing 1/2 tsp of epsom salts and a quart of water and spraying a leaf? Try it out and make sure it doesn't burn one of the leaves first, if it gets better TA-DA! If it doesn't get better, well, at least you can rule it out. I've run into a Mg deficiency before, but it never bleached the plant like that...
yeah I'll have to check that out. When vegging I usually put in a 1 tsp Epson salt every 2-3 watering, but i have never had a strain have these crazy bleach out spots. The last grow, the headband leaves did this shit and by the end were crispy mutha f'ers, but amazing end product. I just feel that it can be even better if I figure this def. out.
Your plant has a virus, a plant cold if you will. Most plants shake them off, if the swirling pattern spreads to the new growth, or spreads to another plant it's more virulent and will cause issues. If it's left over from your last grow, then you will need to clean the walls and equipment with bleach, sounds like a virulent one. Did your last crop finish ok?
The crop turned out great, bit of a pain in the ass trimming with all the shit fan leaves, but end product is pretty smooth and snaps a sweat guard on your head perfectly. I just wish this shit would knock it off. I figured it was the cause of the plant stretching a bit last grow, but who knows.
I was also going to say it closely resembles TMV. If this issue is nutritional then it is likely due to an over abundance of some element in the media preventing the uptake of another element. 1tsp per gallon of Epsom Salt is TOO MUCH! That would add more than 130ppm of Magnesium to your solution. This is a major imbalance and could contribute to temporary lockout of Calcium, Potassium, Iron, and Zinc. 1/4 teaspoon per gallon is more than enough. I usually use a heaping 1/4 teaspoon in 5 gallons of water. When the proper Mg level is somewhere around 40ppm just 10ppm is actually quite a bit from a chemistry standpoint.
I normally don't use Epson salt during flowering. I flush between veg and flowering and go from there. There hasn't been any Epson salt on it in about 5 weeks. Might just be the strain or something.
Whatever you got going on mine look exactly the same, so hopefully someone guesses.... I guessed MG diff so I cut out my cal mag in fear of too much ca locking up mg and replaced with .5 grams of dissolved Epsom salt per gallon and gave a heavy water running off 50%