Rust-Looking Discoloration on One Leaf

[Godswrath]

Hi guys,

I have my plant growing in "living soil" (I used Buildasoil 3.0).

I have a fungus gnat infestation I've been trying to eradicate, so far I've applied BTI a few times, and nematodes twice. It hasn't been too long since the applications, so I'm still hopeful it'll work. Oh, I also have a butt load of sticky traps everywhere lol.

Ok, so far the plant has been looking very healthy. All of the sudden today I noticed, however, one of the fan leaves discoloring.

Before the discoloration, I had just applied the nematodes (about 2 days before the discoloration) and it was pretty heavy watering. So, I have a suspension it's from over-watering.

However, I've also recently begun scrogging it, and that forced me to start putting some pressure on the main vine (I didn't want to top it). The plant has been bending very well, but the place where I hooked onto the stem to start training it is exactly the spot where the discolored leaf was--so perhaps this could be the culprit?

Thoughts? I went ahead and pruned the leaf (is that recommended?). The discoloration does NOT rub off. When I looked under a magnifying glass, it looks like little tiny orange pimples.

I attached three photos: one with the leaf on the plant. One of the front of the leaf after pruned and one of the back of the leaf after pruned.

Thanks for any insight!!

 

[GNick55]

yep overwatering, i got rid of gnats by keeping the soil as dry as possible with the least amount of water when needed basically just a tiny bit down the stem, took a month if that even transplant to same size cups but tried to remove as much of the old soil as possible as gnat larvae are the real problem not the fly as much, also with constant fan on the plants. took about a month but was completely clean of them. no chemicals, nothing..
advice do not compound stress with one thing after the other..

 

[Godswrath]

Ok, great. I was hopeful it was over-watering and not something else. Was the pruning of the leaf necessary or recommended?

I get paranoid under-watering for too long (to let the soil dry out for the gnat problem) since this would be harmful for the microbial life in the soil, no? The soil is much more expensive than the seed at this point (I have a 30 gal pot) lol.

I've thought about getting some perlite or sand and putting it over the soil (a recommendation I read here). But I'm scared it'll be near impossible to remove and basically ruin my soil? I was planning on reusing this soil for a long time lol.

For a future grow, if I can't get this under control with nematodes/bti, I might try wicking the water from under the cloth pot.

 

[GNick55]

Ok, great. I was hopeful it was over-watering and not something else. Was the pruning of the leaf necessary or recommended?

I get paranoid under-watering for too long (to let the soil dry out for the gnat problem) since this would be harmful for the microbial life in the soil, no? The soil is much more expensive than the seed at this point (I have a 30 gal pot) lol.

I've thought about getting some perlite or sand and putting it over the soil (a recommendation I read here). But I'm scared it'll be near impossible to remove and basically ruin my soil? I was planning on reusing this soil for a long time lol.

For a future grow, if I can't get this under control with nematodes/bti, I might try wicking the water from under the cloth pot.

no worries about it being more dry than wet, anyways yes a inch layer of perlite will work, the reasoning is keeping the fly’s from laying eggs in/on the wet damp soil. so yes that helps too. is it an auto flower?
damaged leaves don’t repair themselves but leave them till they get worse, or just remove one or two every few days, but i’d try leaving as long as possible as the plant can still take food from it. kinda a decision you make as you go, but with everything!!
less is more!!

 

[Godswrath]

no worries about it being more dry than wet, anyways yes a inch layer of perlite will work, the reasoning is keeping the fly’s from laying eggs in/on the wet damp soil. so yes that helps too. is it an auto flower?
damaged leaves don’t repair themselves but leave them till they get worse, or just remove one or two every few days, but i’d try leaving as long as possible as the plant can still take food from it. kinda a decision you make as you go, but with everything!!
less is more!!

Thanks, again! It's not an auto flower; it's a photo period feminized from Useful Seeds. I guess if I don't see some improvement soon, I might try the perlite. Is it a huge pain to scoop it back out after harvest?

 

[GNick55]

Thanks, again! It's not an auto flower; it's a photo period feminized from Useful Seeds. I guess if I don't see some improvement soon, I might try the perlite. Is it a huge pain to scoop it back out after harvest?

you could try saving some of it, than rinsing it off let it dry.
it’s cheap enough you can toss it outside when done.
gnats love warm wet humid conditions, don’t provide it for them,?keep it breezy/windy, dry, they are terrible flyers and will run around the top of the soil, sides of cups or underneath to stay out of the wind, it’s easy just research them and try not to provide an environment they like.