Leaves drying up!

[Gloria]

Need ugent help! I’m completely new at this. It seems I’m in pretty late flowering, and my plants look like this now. The leaves started drying up and curling (from the top). Last night I raised the lights all the way up to the tent cieling, and stopped watering. I also went from 4 hours nighttime to six hours. I’ve been watering them quite a lot every day. They are auto-flowering plants, and I read somewhere that they should have a lot of light during flowering, and needed a lot of water. Also, I should strive to get the environment as dry as possible, and now I’ve got it on 36%, and just above 20C. I stopped fertilizing them about a week ago, as I read that close to harvest that was important. What’s going on here? Is it over-watering, in combination with too much light? Have I taken the correct measures? And are the plants beyond saving? That would be really crappy, as they seem so close to harvest. Please help!

[Blowdout2269]

What kinda light? And how close was it?!?

[Gloria]

They are fluorescent tubes. They emit some heat, but I’ve been holding my hand under they to test I’d say they were about 40cm above the plants. Now I’ve moved them all the way up. You think they’ll survive until harvest?

[Blowdout2269]

Survive? Yes.
Though the yield will likely suffer.

[kingfish]

Looks like heat stress. Don't let the temp get over 85 degrees.

[Gloria]

Heat’s been pretty steady at 21C (70F) approx.

[Blowdout2269]

Ok, well I don't see fluorescent tubes doing this damage, but i could be wrong. Are you checking the pH? I'm betting that this is caused by pH or root issues. Just so you know, the leaves will not recover. You'll have to correct the best you can and tough it out. I suggest researching the main GWE site for an attempt at a better diagnosis.

[ChubbNugg]

strong fan, Ph imbalance, and under watering?

[Gloria]

Been watering alot, but I can cut the fan I suppose. Don’t know much about ph tbh🤷🏽♀️

[Franklin]

Just taking a wild guess since it's not heat, but any sign of thrips? They're very hard to see but if you're patient you can find them. Some of the browning looks a little like thrip damage. Not a lot. But worth an inspection because thrips are fairly easy to remedy. Good luck, aside from this leaf issue looks like you've done pretty well for a first grow!

[Gloria]

No bugs in there, guaranteed. Will I be able to harvest those buds you think? Trisomes are still rather clear, and I was hoping to go a bit amber.

[Rwise]

What I see is possible bugs (white spots), PH fluctuations, deficiencies. These came from the "Plant Problems" page hit the link above to study all of them.

https://www.growweedeasy.com/cannabis-plant-problems/calcium-deficiency

https://www.growweedeasy.com/cannabis-plant-problems/manganese-deficiency

https://www.growweedeasy.com/cannabis-plant-problems/copper-deficiency

https://www.growweedeasy.com/cannabis-plant-problems/heat-light-stress

https://www.growweedeasy.com/cannabis-plant-problems/ph-fluctuations

https://www.growweedeasy.com/cannabis-plant-problems/overwatering

https://www.growweedeasy.com/cannabis-plant-problems/potassium-deficiency

https://www.growweedeasy.com/cannabis-plant-problems/root-problems-cannabis

PH is of great concern, get equipment and learn how to use it, OR go full blown organic.

[SoOrbudgal]

Morning from Oregon Gloria. Yes you will be able to harvest but those leafs may all fall off do to the heat. Just try an not let the fan blow directly on those plants now, You already raised up the light good, water only like others have said.