Marijuana leaves damaged, please identify

A question from a fellow grower:

Hello, I’m about 4 weeks into flowering my 707 Headband strain and in
starting to notice damage to the leaves, more concentrated on the
bottom. I thought mobile nute deficiency, but the damage doesn’t look
like what I’ve researched. So I think it might be a disease or fungus.
Could you identify the problem for me and maybe give me some solutions;
homemade and store bought. Thanks. I’ve attached some pictures here,
they’re old pic during veg, bit the damage is the same and getting worse

We could use more info. What are the parameters in your grow?

Let’s get you started with a support ticket, answer all the relevant questions the best you can and we might be able to get an idea of what is going on.

If you do not know, or do not use something, just say so or put ‘NA’.

ILGM Support Ticket:

What is the strain and type(strain name, unknown bag seed, regular seeds, feminized seeds, auto-flower, etc)?

Indoor or Outdoor? If outdoor, planted in ground or in a container?

Size of space (max height and area, length/width)?

Soil or Hydro? Type of Medium used? System type?

pH? Of the soil or medium (root zone/reservoir/runoff) and of the water and/or nutrient mix that is fed to the plant?

Type and strength of nutrients used? NPK? EC/TDS/PPM levels?

Temperature? Day vs. night temp or highest and lowest temps? Root zone temps?

Humidity %?

Light system/watts/lumens/FLUX/PAR?

Ventilation system? Size? CFM? CO2? AC, Humidifier, De-humidifier?

Number “weeks/days” from into Season, Vegetative Growth or Bloom/flowering?

Add anything else you feel would help us give you a most informed answer. Feel free to elaborate, but try to be brief and to the point. Short and to the point questions and facts will help us help you :slight_smile:

Hey, thanks for the reply. I’ll try to answer all your questions.

Strain: 707 Headband. FEM, From Humboldt
Indoors, in a 2’ high and 2’ diameter (gets smaller towards the bottom)
Max height 5’ being one foot away from the light, 1.5-2’ width
Soil…well soilless peat, Promix HP. Worm castings. Blood,Bone,Kelp meal and Dolo Lime used.
I always try to adjust solution to 6.5. I dont check run off or soil.
Gen Organics- Biothrive grow+Bio Root during veg, Biothrive bloom+ Koolbloom (weening off grow and root first 2 weeks in flower)
Day- 24-26 C. Night- 22-23 C
Humidity- No meter ( why I suspect fungus/disease)
600W MH during veg. 600W HPS flower
6’’ Fan with exhaust out room and intake attached to reflector, near bulb.

Hope this helps, thanks!

P.s Those pics are from 7-8 weeks into veg. They are now 5 weeks into Flower. Problem isnt getting better :confused:

Do you adjust the pH of the pure water? And what type of water? Tap, R/O, etc?

Knowing the pH of the soil could rule out a pH problem.

Knowing the humidity might help point in the direction towards mold/fungus, or away from that suspicion.

The spots do look unusual, so I’m not as quick to jump to a pH problem, but it could be. And I’m thinking you are correct and it is from too much moisture on the leaves. You need to know what your humidity is and get it under control before you get botrytis.

You don’t have a circulating fan in the room?

Fenris I agree with Mac G. The spots are unusual. Can you post an updated pic of the spots to compare progression if any?

I do have have l fans, two standing ocsilating, one wall fan pointed at the bulb pushing the air towards my intake. And one pointing at my ballast as I couldn’t set up it up outside my room.
And I use tap water that is usually perfectly at 7. But after nutes I have to use PH up cus it’s goes to around 5.5
I just took pics but not sure how to upload them with this comment…

I do see something kind of like powder or fuzz, maybe in a couple of the previous pictures, this could be “powdery mildew”, a type of fungus that can lead to botrytis. I’m not sure more pictures will help.

Drastic measures would be to put a sulfur burner in the room, it will kill the fungus, and I’ve seen it used to save a garden, but I bet the harvest might not have tasted all that great, maybe they were able to wash all it off before harvest.

But one of the best things to do is “know” what your humidity is in that room and get it under control. buy some hygrometers, they aren’t that expensive, I’ve seen ones with good ratings on e-bay and amazon for around $10, that will give you an idea and in the meantime crank up the air exchange in the room, the exhaust fan and or inlets to get more fresh dry air inside will help.

Without knowing what the humidity is now, we won’t know for sure if it is the humidity that is building up in the room and is the likely cause.

If adding more fresh dry air does help, it is likely a good bet that was what it was, but you won’t be able to see how changes in exhaust fan speeds or venting do improve humidity conditions, or maybe make them too dry, if you don’t have a way of measuring the relative humidity.