Help Please, Plant Issues! Bugs or Nutes?

[Eager2Grow]

Hey guys,

I am running a grow from veg and I have been having some problems. I have four plants (three Kosher Kush, one Brotherhood OG; all from seed) in a 4x4 under 400w, will be using 600w to flower.

I had to cut my last grow down due to insect problems. I sterilised everything with bleach and shut everything down. I had some minor insect issues earlier in the grow, but got on it early with neem and insecticidal soap. I can no longer see any bugs, but the leaves on the bottom of my plants are still going yellow and grey. I thought it was still bugs, but I am starting to wonder if maybe the issue is a nutrient deficiency, as the plants are fairly large for veg and I am not giving them heaps of nutes (though I do feed every water).

I also considered the possibility that it is some kind of mold from all the spraying, but since it is summer here, the plants are in veg, and there is no obvious signs of PM/botrytis I am not sure it is that.

Any advice or comments appreciated!

 

[Mikell]

Feed strength (EC/PPM, pH. My heaps to EC converter is broken.), water quality (EC, pH), watering frequency (run off?), environmental conditions?

Are the leaf stems brittle and weakly connected to the plant?

Do you flush periodically? Particularly of concern when fertigating.

 

[Eager2Grow]

I have been using 1.4 EC/690 ppm and pH 5.7. My plants are growing in coco/perlite (70/30). I hand water, and apart from a few feeds of straight water I haven't been flushing as the nutes are reasonably low (plants are roughly 9-10 weeks old from seed). I water to 10-20% run off around every three days (the pots are reasonably large, I think 10L).

The leaf stems are brittle and weakly connected to the plant, yes.

I don't have any temperature control in there, so the temperature is a bit variable. It has been summer here and I have lights off during the hottest time of day (9am-3pm), I guess the temperature would probably vary between 20 and 35 degrees celsius. Humidity probably varies from 30-60%, right now with lights off it is at about 55%.

 

[Mikell]

I notice the bit with the weak and brittle right before mildew or other foliage disease. Later stages of root rot can produce similar symptoms. Wide humidity swings are favourable to infection of the foliage.

I would treat preventatively above ground and below. If you can check roots that would be ideal.

You should be watering daily. That amount of perlite will wick the medium evenly, and while it looks moist it can be dangerously dry. How light are the pots when you go to water?

Feed strength looks fine, if that number is total EC and not feed EC alone.

I'm pretty tired but I think that's all I had to vomit.

 

[who dat is]

Apologies as I only grazed through the previous posts but the pictures look like the beginnings of a P deficiency?

 

[Eager2Grow]

I notice the bit with the weak and brittle right before mildew or other foliage disease. Later stages of root rot can produce similar symptoms. Wide humidity swings are favourable to infection of the foliage.

I would treat preventatively above ground and below. If you can check roots that would be ideal.

You should be watering daily. That amount of perlite will wick the medium evenly, and while it looks moist it can be dangerously dry. How light are the pots when you go to water?

Feed strength looks fine, if that number is total EC and not feed EC alone.

I water when the pots get light, usually it is 2-3 days between waters. The pots are still quite heavy the day following a water, in particular.

How would I treat mildew or foliage disease preventatively?

Apologies as I only grazed through the previous posts but the pictures look like the beginnings of a P deficiency?

I am starting to think it may be P deficiency, maybe with a touch of N deficiency too. I upped the nutes today, will see how that goes.

 

[Eager2Grow]

So I was looking at the leaf damage and there is some whiteness on the tips where the leaves are dried out. I have been spraying them with insecticidal soap, so it could be that, but I am thinking PM is a lot more likely. I uploaded some photos, but they are poor quality.

Some questions:
- Is it viable to flower these plants after treating for PM?
- I was going to flower in the next few days, I take it my best course of action is to postpone this and thoroughly treat the PM?
- One plant is affected much worse than the others, should I cull this one?
- What is the most effective treatment for PM?

 

[who dat is]

Take better pictures of the spots in question as none of those turned out. I would imagine it would be the soap though since it is on the tips of the leaves and I think it unlikely that PM would show up on dead parts of the leaves after it was already dead. On another note you might want to give your plants a break with the soap or switch up and rotate sprays as it looks like it's burning the smaller plant in one of your pictures.

 

[Eager2Grow]

Unfortunately I am unable to take better photos as that is my only camera. I got some potassium bicarbonate spray just in case it is PM.

 

[who dat is]

I think the camera is fine and you will still be able to take better pics. The problem though is that it is trying to focus on the ground and what is beyond your leaf tips. Try taking the same photos but hold up a piece of white paper behind the leaf so that the only thing that is in your photo is the leaf tip with the white paper background. Make sure to focus it on the leaf tip and I think you will get way better pictures

Use your flash also if you need to. Maybe 2 pictures each with and without flash?

 

[fredDRO.MoBB]

on all pics I see no pm at all. u do kno what pm looks like?

 

[Eager2Grow]

Here is my laatest attempt, still didn't turn out well. I know this doesn't look super typical of PM, but what else is causing white powder on leaves.

 

[who dat is]

I still think it's residue from dried up IPM sprays. Not powdery mildew

 

[Eager2Grow]

Awesome, I hope you are right. I will spray the plants and wipe the walls with potassium bicarbonate again tonight just to be sure. Any ideas what is wrong with my plants? I can't see any bugs and they were treated heavily with insecticide for weeks. I upped the nutes and things seem to have improved, but it isn't all roses yet. I really need to flip ASAP as the tent is getting mighty crowded and for scheduling reasons if I leave it much longer I wont have time to trim.