Brown almost mosaic looking patches on leaves

lamptree

New Member
Hey guys,
Just wanted to make a post asking for help with some brown patches I’ve been noticing on one of my plants. They developed a little less than a week ago and have quickly spread to a number of other leaves on my plant. I’ve been trying to diagnose the issue, but I’m unable to find anything that looks exactly like this. Any help anyone can provide would be appreciated!
 

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Flaming Pie

Well-Known Member
We're these plants put outside recently? Sometimes a shock to the plant like sudden high heat and high wind or low humidity can cause burns like this. If the plants were babied their cells have not formed resistance to handle such a huge increase of wind sun and heat. Plants put their resources into what they need. If they are in a low wind, moderate heat and humidity chamber they build themselves to handle that. Sudden changes can tear them up for a few days until they manage to put resources into strengthening the new cell requirements for their new environment.
 

lamptree

New Member
I’m growing outdoors in Ontario, the season has been quite rainy, I’m using promix organic soil, I’ve been dealing with whiteflies recently and as a result I’ve been using a neem and dawn solution on the leaves, I’m using Dutch sciences grow girls grow fertilizer and feeding once a week because of how much rain we’ve had, I’ve intermittently used marphyl soil enhancer, I ate yogurt for breakfast, I’m wearing a grey t shirt, and it’s Thursday at 11:43am. If you need any more details please specify and I’d be happy to provide.
 

lamptree

New Member
We're these plants put outside recently? Sometimes a shock to the plant like sudden high heat and high wind or low humidity can cause burns like this. If the plants were babied their cells have not formed resistance to handle such a huge increase of wind sun and heat. Plants put their resources into what they need. If they are in a low wind, moderate heat and humidity chamber they build themselves to handle that. Sudden changes can tear them up for a few days until they manage to put resources into strengthening the new cell requirements for their new environment.
Unfortunately not, they’ve been outdoors for around a month and a half now.
 

jochhe1998

Active Member
Off the bat, the only nutrient deficiencies I think it could possibly be are phosphorous or calcium. Considering you're in veg and growing in soil either of those would be a bit strange to have.

What is your runoff PH?

I've had similar burn spots from neem before. What concentration, frequency, and what time are you spraying the neem?

Intuition is telling me it doesn't have much to do with rain but I could always be wrong. I am leaning towards the neem.
 

lamptree

New Member
Off the bat, the only nutrient deficiencies I think it could possibly be are phosphorous or calcium. Considering you're in veg and growing in soil either of those would be a bit strange to have.

What is your runoff PH?

I've had similar burn spots from neem before. What concentration, frequency, and what time are you spraying the neem?

Intuition is telling me it doesn't have much to do with rain but I could always be wrong. I am leaning towards the neem.
I have not checked the runoff pH, just the soil pH initially, but I think perhaps that could have something to do with it. I’ve been wondering if I could be having phosphorous issues from nutrient lock out or too lax of a feeding schedule. I will re test the pH and see if I’m having issues in that department.

As for the neem oil, that could have something to do with it. I have been spraying almost daily due to a pretty bad whitefly infestation in my garden. My solution has been 1/2 tsp neem, 1/8 tsp dawn, per 500ml of water. Usually I spray in the morning which could also be increasing the intensity of the sun on my leaves, but it’s strange that it’s only on the bottom and mid level leaves.
 

Flaming Pie

Well-Known Member
Unfortunately not, they’ve been outdoors for around a month and a half now.
How well does your soil drain? You said it has been raining alot. Was the wind high during these storms.

Maybe the dawn didn't work very well as an emulsifier? I've never used soap. When I need to apply a foliar for feeding I use green cure with it that has an excellent emulsifier in it. Raises ph of leaf surface and gives a bit of potassium to plants. When I had thrips I used bonide captain Jack's dead bug spray. It uses bacteria to kill insects and works very well.

It looks like burn (cells dying from exposure to something in excess) not bugs to me.
 

Flaming Pie

Well-Known Member
I have not checked the runoff pH, just the soil pH initially, but I think perhaps that could have something to do with it. I’ve been wondering if I could be having phosphorous issues from nutrient lock out or too lax of a feeding schedule. I will re test the pH and see if I’m having issues in that department.

As for the neem oil, that could have something to do with it. I have been spraying almost daily due to a pretty bad whitefly infestation in my garden. My solution has been 1/2 tsp neem, 1/8 tsp dawn, per 500ml of water. Usually I spray in the morning which could also be increasing the intensity of the sun on my leaves, but it’s strange that it’s only on the bottom and mid level leaves.
That is not phosphorus defiency
 

mandocat

Well-Known Member
Looks like leaf septoria to me. I'm in Oklahoma and the hot humid weather has made this fungal infection hammer my outdoor garden. I have been spraying a sulphur based solution for the last month, which at least slows it down. I will probably lose several plants before harvest, same thing happened last year.
 

Flaming Pie

Well-Known Member
I see magneisum deficiency in 2 of your photo. Magnisum is pulled from between the veins. Mild cases will look like number 3. Lime green from tip up into regions between veins. Calcium is more small spots and circles between veins. Phosphorus deficiency would not be confined within the veins. It would eat up entire sections veins included.

Some spots look like burns might be light burn from a strong spray dilution, other spots look like the plant eating itself.
 

jochhe1998

Active Member
Looks like leaf septoria to me. I'm in Oklahoma and the hot humid weather has made this fungal infection hammer my outdoor garden. I have been spraying a sulphur based solution for the last month, which at least slows it down. I will probably lose several plants before harvest, same thing happened last year.
definitely look into this^.

Neem twice a day will cause burns in my experience. IF it is fungal, I'd switch to sulphur-based sprays - maybe with a little copper mixed in if you don't mind heavy metal in your weed.
 

Flaming Pie

Well-Known Member
greencure-fungicide-400x364.jpg
In case it is fungal. One small scoop to 250ml water once or twice a week.

Also can be mixed with epsom later to treat magnesium or Sulphur deficiency.
 

lamptree

New Member
View attachment 4953891
In case it is fungal. One small scoop to 250ml water once or twice a week.

Also can be mixed with epsom later to treat magnesium or Sulphur deficiency.
Thank you very much for your replies, this has given me a lot to go on. I looked into the GreenCure fungicide, but unfortunately I can’t find any vendors in Canada. Do you happen to know of any solid alternatives? Strong spray solution does make sense and I will also try to increase my magnesium supplementation.
 

lamptree

New Member
Looks like leaf septoria to me. I'm in Oklahoma and the hot humid weather has made this fungal infection hammer my outdoor garden. I have been spraying a sulphur based solution for the last month, which at least slows it down. I will probably lose several plants before harvest, same thing happened last year.
It does definitely appear as leaf septoria in parts. What solution are you using in particular?
 

lamptree

New Member
A long time grower friend that owns a grow store created his own formula. Don't you have any sulphur based fungicides in Canada?
Oh yes I’d imagine so, I’m quite new to growing cannabis though so I’m just trying to feel it out. I’ll read some reviews and see what I can find at a hardware store.
 

myke

Well-Known Member
I’m in Canada also. This is what I use for PM and other crazy things 15 ml powder to one litre water. Shake it up good and spray. Leaves a thin white layer of sulphur. 26EAF431-F1DE-485B-802B-640355A4BB9C.jpeg
 
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