Septoria(leaf spot)

Growing in Northeast and it has been a very wet summer- and lucky me has encountered Cannabis Septoria on almost all my plants. It starts out as yellow dots on fan leaves and progresses to brown as leaf dies. Can be treated with copper fungicide (Bonide) if caught early and will not affect buds other than the loss of leaves. The downside is that this is a spoor problem and will return next year if not dealt with. All leaves affected should be removed and destroyed to prevent spoors from overwintering, ground tilled after crop, and aggressive spraying with fungicide the next year. To late for me to treat but hope this helps others.
http://www.ilovegrowingmarijuana.com/marijuana-diseases-leaf-septoria/
Will post pics later.

I hit it with serenade only to make the problem progress. I have tried other fungicides in the past as well, with organics and chemicals. The two best fungicides I have found that really stop it once it starts is myclobutanil ( Eagle 20, Immunox) and Captan. You can buy the captan in bulk powder (water soluble) at most local farm supply stores for about 20 bucks. It has a low toxicity rate.

The Captan will work better for botrytis aka "bud rot" and the myclo is better for leaf spot.

People will bash it, but usually if the rains don't wash the captan off by time I harvest I will wash them myself with water. The Eagle 20 is systematic so you can't wash it, just make sure and spray at the least 30 days before harvest.

Following. I have spotting around the edges of my fan leaves and I'm curious if that's what's going on.

You can't use a copper based fungicide on cannabis. Unless you feel like smoking copper. Heated it turns into a toxin. Copper fungicide is for roses, honey suckle. Stuff you don't eat or smoke.

I hope you don't expect to sell it...


Here's an interesting thread.

https://www.rollitup.org/t/lets-talk-about-rust-fungus-what-you-need-to-know.614137/

Eagle 20 turns into cyanide when its burned.

SouthCross said:

You can't use a copper based fungicide on cannabis. Unless you feel like smoking copper. Heated it turns into a toxin. Copper fungicide is for roses, honey suckle. Stuff you don't eat or smoke.

I hope you don't expect to sell it...


Here's an interesting thread.

https://www.rollitup.org/t/lets-talk-about-rust-fungus-what-you-need-to-know.614137/

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copper is not systematic,it washs off with the rain it kills the spores on the leaf that's it,an it is listed for organic gardening

thumper60 said:

copper is not systematic,it washs off with the rain it kills the spores on the leaf that's it,an it is listed for organic gardening

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You don't smoke tomatoes, or okra. Cannabis isn't a produce plant. Copper based fungicide renders it unsmokable. Anywhere it touches the plant. Potassium based fungicide is another no-no.

There's lots of stuff that can washed off produce in the kitchen sink. Not so with cannabis. If it was safe I'd be using it myself. It's also why I grow my own weed. No worries about poisonous copper residue. Or eagle 20....or the banned garbage from Mexico.

SouthCross said:

You don't smoke tomatoes, or okra. Cannabis isn't a produce plant. Copper based fungicide renders it unsmokable. Anywhere it touches the plant. Potassium based fungicide is another no-no.

There's lots of stuff that can washed off produce in the kitchen sink. Not so with cannabis. If it was safe I'd be using it myself. It's also why I grow my own weed. No worries about poisonous copper residue. Or eagle 20....or the banned garbage from Mexico.

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soo what u use for leaf spot,got a feeling u never had it,like I said it washs off in the rain never seen leaf spot indoor,an the link u posted has nothing to do with leaf spot or any thing bad about using copper?

thumper60 said:

copper is not systematic,it washs off with the rain it kills the spores on the leaf that's it,an it is listed for organic gardening

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Thank you, Thumper- It is also used for tomatoes and peaches and does wash off- and is only used on leaves early on-not planning on spraying buds with it and if it was systematic, it wouldn't be used on produce.Too late this year other than removing effected leaves and finishing.
Some people can't tell North from South

thumper60 said:

soo what u use for leaf spot,got a feeling u never had it,like I said it washs off in the rain never seen leaf spot indoor,an the link u posted has nothing to do with leaf spot or any thing bad about using copper?

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I currently have rust on a seedling. One out of eight plants. I'm treating it with Bacillus Amyloliquefaciens. The same stuff that's in hydrogaurd but at much higher concentration. Hydrogaurd has 0.038%. I'm using Southern Ag Garden Friendly Fungicide. It's 98.85% of bacillus Amy. Mixed thick with about a liter of rain water.

I add lots of Hydrogaurd to compost tea. As in tip the jug and pour it in. The Southern Ag is sprayed on the plants. I've bombing the whole grow space with the stuff. Dirt, sides of the pots, the plants. So far I've treated them three times. Three days apart.

Have no idea if it'll work. I do know copper can't be used on cannabis. The combustion of the plant charges it. Similar to Eagle 20. You can use it in the garden but you can't smoke it.

I have been fighting this shit 2 decades,if u catch it early only need to spray 2-3 times once u have it once u will never forget

SouthCross said:

I currently have rust on a seedling. One out of eight plants. I'm treating it with Bacillus Amyloliquefaciens. The same stuff that's in hydrogaurd but at much higher concentration. Hydrogaurd has 0.038%. I'm using Southern Ag Garden Friendly Fungicide. It's 98.85% of bacillus Amy. Mixed thick with about a liter of rain water.

I add lots of Hydrogaurd to compost tea. As in tip the jug and pour it in. The Southern Ag is sprayed on the plants. I've bombing the whole grow space with the stuff. Dirt, sides of the pots, the plants. So far I've treated them three times. Three days apart.

Have no idea if it'll work. I do know copper can't be used on cannabis. The combustion of the plant charges it. Similar to Eagle 20. You can use it in the garden but you can't smoke it.

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we r talking leaf spot not rust,at least u amit it can be used on veggies,now show me how bad it is on cannabis,copper is nothing like e20 get real

thumper60 said:

we r talking leaf spot not rust,at least u amit it can be used on veggies,now show me how bad it is on cannabis,copper is nothing like e20 get real

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On no. I'm not the one using a copper based fungicide on cannabis. That research is on you. I've also been fighting fungus for decades on a variety of plants. I thoroughly researched it for my smokable plants. To make the research easier. Search for a smokable fungicide for a soft leaf plant. And don't think over mist isn't getting in the buds when you're spraying the leaves.

SouthCross said:

On no. I'm not the one using a copper based fungicide on cannabis. That research is on you. I've also been fighting fungus for decades on a variety of plants. I thoroughly researched it for my smokable plants. To make the research easier. Search for a smokable fungicide for a soft leaf plant. And don't think over mist isn't getting in the buds when you're spraying the leaves.

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your the one saying its so bad,show me iam not to old to change lol I have used serenade,green cure,organacide, none of them touched black spot please enlighten me, so put up or shut up

As Thumper said, you use it early when there is no bud forming as a preventitive- and at this point-within 2 -3 weeks of chopping, leaves will get eaten up, so another non-issue- just cut off effected leaves and burn/destroy for next year. This is a non-arguement for people spouting knoweledge when growing indoors and talking apple & oranges- I follow Thumper & he knows WTF he is talking about. I grow in and out and have learned a great deal from CERTAIN experienced people

thumper60 said:

I have been fighting this shit 2 decades,if u catch it early only need to spray 2-3 times once u have it once u will never forget

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So how many times do u spray hiw far apart before u seen positive results

Weezyf420 said:

So how many times do u spray hiw far apart before u seen positive results

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If your in the usa an growing out door black spot has not hatched yet, Mid july is when it hits the northeast back then i was growing in swamps no black spot for me in 3yrs. but learn what it looks like an hit it early with copper once a week or after rain.

Ok thanks yea I'm in the fl swamps in a greenhouse house humidity is horrible
Thanks I'm getting southern agricultural copper fungicide spray today hope that does the trick

Weezyf420 said:

Ok thanks yea I'm in the fl swamps in a greenhouse house humidity is horrible
Thanks I'm getting southern agricultural copper fungicide spray today hope that does the trick

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Would love to see a pic of the leaf spot it should have yellow ring around the black spot.