Looking for guerillas with leaf spot diease experience.

[Creeperpark]

Ah fuck its EVERYWHERE here now in the northeast. Every surrounding weed/shrub has it near my grow. As a beginner I naively assuming things were going well . A dozen or so plants smack in the middle of it. I had bought some gardensafe fungicide3 last week to spray as a preventative but turned up to check on my plants and sure enough on a bunch of the big fan leaves had some spots so I sprayed the whole bottle on 12 plants. I think this is black spot not septoria. Seems like the very early stages, I removed all the infected leaves a couple days in a row and cut back the vegetation a ton. Probably going to be a long battle with this the summer, was really bummed out until I found this thread. Some good options here... I will have to act fast before next weeks visit- baking soda and H2O2 sounds appealing but im afraid of it being too weak. Garden sulfur sounds good too. I didnt take a pic of the worst leaves but only about one area or blade was badly infected in the worst leaves. Plants still look ok but i worry

View attachment 18731958 View attachment 18731959 View attachment 18731960

One thing that would help in your case is to keep the soil aerated more and don't let it pack on top. Take a hand cultivator and loosen the top inch or two of soil after the soil is watered and dries again. Never let it pack and if moisture is a problem pull all the mulch away from the plant. If you put a lot of baken soda on your plants that stuff gets in the soil and does damage to the soil. Remove the mulch and keep the soil aerated and loose and your plants will be good to go.

 

[hamstring]

Ah fuck its EVERYWHERE here now in the northeast. Every surrounding weed/shrub has it near my grow. As a beginner I naively assuming things were going well . A dozen or so plants smack in the middle of it. I had bought some gardensafe fungicide3 last week to spray as a preventative but turned up to check on my plants and sure enough on a bunch of the big fan leaves had some spots so I sprayed the whole bottle on 12 plants. I think this is black spot not septoria. Seems like the very early stages, I removed all the infected leaves a couple days in a row and cut back the vegetation a ton. Probably going to be a long battle with this the summer, was really bummed out until I found this thread. Some good options here... I will have to act fast before next weeks visit- baking soda and H2O2 sounds appealing but im afraid of it being too weak. Garden sulfur sounds good too. I didnt take a pic of the worst leaves but only about one area or blade was badly infected in the worst leaves. Plants still look ok but i worry

View attachment 18731958 View attachment 18731959 View attachment 18731960

I would like to see more pics because this atypical of what i have seen for leaf spot signs. Normally its not striped or variegated. Its small spots that turn brown.

Not trying to minimize your issue I know personally how devastating leaf spot can be.

 

[laszlokovacs]

I would like to see more pics because this atypical of what i have seen for leaf spot signs. Normally its not striped or variegated. Its small spots that turn brown.

Not trying to minimize your issue I know personally how devastating leaf spot can be.

No- I get what you mean it does seem pretty atypical. I don't have great pictures unfortunately. I believe the area I'm growing in has a great deal of blight and leaf spot and I am seeing both and was thinking it was the same for a while. When I first noticed signs on the plants they were very minimally infected with spots/marks on between 5-10% of the leaves with a small suface area on the leaves. I sprayed fungicide3 on them which claims to control leaf spot/blight about 3 weeks ago and dusted with sulfur powder 10 days ago in hopes or controlling everything. Since spraying the fungicide i have seen little to no leaf spots on the majority of the plants.

I could be mistaken as this is all new to me as a beginner however the surrounding vegetation appears to be covered in some sort of disease and riddled with spots. I dont have great pictures on hand but this might be more helpful-

Nearby vegetation that I believe has some form of blight I have seen on my plants as well-

The weeds/brambles/bushes surrounding my plants all have these dots/spots I have been treating as though they are leaf spots. This leaf is not nearly as badly infected as some of the weeds/plants near my ploy.

Finally here is a leaf on a cutting I took about a week ago. One cutting from the same plant stayed the same lush green color in the water and the other one became a bit unhealthy and this appeared on many of its leaves. This is what I believe is/have been calling leaf spot.

Please correct me if i'm wrong. I apologize for the bad pictures, I will try to take more if these are unclear but I also hope that there isn't much disease to photograph when I next check up on my plants

 

[hamstring]

I am far from an expert and I would wait for others to chime in but this is what I would expect to see. Again it doesn't mean its not leaf spot on your plants it just doesnt look like the typical signs. If you have access to liquid cooper I would try that but not on flowering plants.

Starts out looking quite tame and nothing to worry about.

A week or so later

Then its a train wreck in 3-4 weeks

.

Quote Reply
Report Edit

[

 

[laszlokovacs]

Ok interesting I did not know that the specific disease you were referencing was Septoria leaf spot- there are several types as mentioned in the thread but generally I believe most of the sprays work for the different spots. I definitely had septoria on my tomatoes last year and learned what it was for the first time but it was later in the season that it got bad. I currently have some leaf spot on some of the lower tomato leaves. I also got septoria I believe on the only outdoor plant I've grown before this year (an auto that stayed tiny) I think this was septoria but could be mistaken.

My plants seem pretty untouched so far, have sprayed with fungicide and dusted with sulfur this month. Slight leaf hopper damage but other than that biggest flaw seems to be about 5% of leaves on 1/2 the plants have slight blotching I think might be septoria. I could be mixing it up with black spot as well in fact I think theres a good chance this is black spot fungus giving the surrounding vegetation. I will probably remove the leaves with spots but here are some current pictures- not badly infected just yet- what do you think septoria or something else? Hope to only spray with Lactobacillus until end of life cycle but flower hasnt really started yet. Probably fewer than 10 leaves total have these spots/splotches-slightly hard to photograph early in the lifecycle but have been keeping an eye on this stuff on the leaves past month.

 

[hamstring]

Ok interesting I did not know that the specific disease you were referencing was Septoria leaf spot- there are several types as mentioned in the thread but generally I believe most of the sprays work for the different spots. I definitely had septoria on my tomatoes last year and learned what it was for the first time but it was later in the season that it got bad. I currently have some leaf spot on some of the lower tomato leaves. I also got septoria I believe on the only outdoor plant I've grown before this year (an auto that stayed tiny) I think this was septoria but could be mistaken.

My plants seem pretty untouched so far, have sprayed with fungicide and dusted with sulfur this month. Slight leaf hopper damage but other than that biggest flaw seems to be about 5% of leaves on 1/2 the plants have slight blotching I think might be septoria. I could be mixing it up with black spot as well in fact I think theres a good chance this is black spot fungus giving the surrounding vegetation. I will probably remove the leaves with spots but here are some current pictures- not badly infected just yet- what do you think septoria or something else? Hope to only spray with Lactobacillus until end of life cycle but flower hasnt really started yet. Probably fewer than 10 leaves total have these spots/splotches-slightly hard to photograph early in the lifecycle but have been keeping an eye on this stuff on the leaves past month.
View attachment 18738396 View attachment 18738395 View attachment 18738394 View attachment 18738393

They look great, I think you have some pretty healthy plants. Good luck you hope they do well.

 

[laszlokovacs]

Thank you! I appreciate the second opinion. I think they will be pretty manageable if they dont get too bad. Will spray at least a couple times with LAB but will probably leave alone otherwise- hoping they do ok.

Theyre mostly upright which I think helps a lot, septoria finally attacked my tomato plants and although it started after my cannabis plants got it its much worse, probably gonna be more tricky managing the tomatoes.

 

[xet]

I brew my own compost teas, grow in dozens of random locations, everything from clay to rock to sand, and my plants stay happy even when nature around them is all diseased.

Mastering compost tea is like playing the game with the whole cheat code book.

 

[Mozes]

Stay low on fert and away of simple npk to keep the soillife complex…. Micronutrient definciencies lower immuneactivities as does in humans

 

[Pédetoddy]

someone know this fungus?

 

[hamstring]

Wow, seems a little late into the problem to ID.

 

[hamstring]

Stay low on fert and away of simple npk to keep the soillife complex…. Micronutrient definciencies lower immuneactivities as does in humans

I totally agree, any stress makes it easier for disease to take hold.

I grew tomatoes and peppers in containers this year. You could see they were stressed. My tomatoes got leaf blight pretty bad. When I compared them with a friend who grew in the ground there was a big difference. My peppers did not get near as large as if grown in the ground.

 

[bonghopper]

Yo yo Septoria crew, what a devastating disease this is indeed, botrytis is grand in comparison, at least you get flowers! I've had whole plots defoliated before flower, plots looking great, till the dreaded spots appear end June, thanks for all the info on this thread, I tried the copper for one season, but the taste in the flowers put me off for good.

What has been working for me:
Soil testing and amending - making the right trace minerals available and balanced
Living Nettle Mulch, cut back throughout the season, left up over winter in vegetative state - evergreen here
Site selection - Blackberry (Rubus) seem to host more septoria here than the reeds in the marsh, or nettles.
Large scale selection (can be close together) - has brought excellent results - then can be used as breeding tool.
Strain selection

Local Largescale Conventional agriculture, especially grain and tillage in the surrounding lands, with widespread use of various fungicides and herbacides causes imbalance in the local ecosystem.

Most Septoria resistant Strain Finds of the last season for me - (barely any spotting compared to it's melted neighbour and still with main fans leaves intact! Woohoo!)

Purple Satellite
UELsat x Punto Rojo
Mextiza and its UEL hybrids

Will keep on finding more

 

[Creeperpark]

The number one cause of outdoor plant disease is planting plants too deep in the soil and in the wrong soil porosity or soil drainage. Not just cannabis plants but any woody stem plants. When you plant too deep in soil that doesn't drain you will get leaf spot, stem rot, bud rot, mold, or any other common fungal diseases. The reason is the plant has long periods of setting in wet soil. You can spray fungicide all you want but it won't change the fact the plant is setting in water.

If you raise the soil a good 12 inches where the soil is wet and only grow in good draining soil you won't have problems with any kind of fungal diseases. It's not the plants it's the grower and where and how the plant is planted that causes the problem with leaf spot. When I see the plants above in the photos I see plants that are too deep in the ground and planted in wet soil. The only way a pathogen can enter a plant is thru soggy wood.

 

[bonghopper]

Sound advice Creeperpark, wet clayey lifeless soil is a recipe for pathogens.
Some plants and strains are way more tolerant than others however, very useful for guerilla grows where one does not have the resources to make perfect garden beds with optimal aeration and irrigation.

I see plants untouched beside their completely melted neighbour, even within the same strain, in the same conditions in a raised bed together. In marginal climates, in clay soil (a cool temperate 53N), I see strain and plant selection as the next necessary step to get a crop, obviously taking preventative drainage measures - but not too much that they're too far out of the water table and are too dry for good vigorous vegetative growth, a nice middle ground (I never irrigate)

Very promising and quick results so far, the F7 gen had 20 out of 35 females that made the cut, compared to one of the parent F6 lines with only 2 out of 40 female. This all done on the same high pressure spot, that has had really bad septoria for 5 seasons.

Mentions of septoria resistance from breeders is sparce enough, most breeding in the 'west' is done in dryer, warmer climates and indoors.

With regards to planting too deep - this is strain dependent as to whether they root up the stem - some respond to this more than others and help anchorage (I don't stake). If the soil is too wet to plant a plug 2" deeper up to the cotyledons, it's too wet to grow in anyway...

 

[bbrandon888]

Have anyone tried buildasoil organic living soil ? I heard growers mentioned up here that they were able to grow mold and leaf septoria resistant plants outdoors. Also I was reading in another thread that someone was using it and didn’t have leaf spot on plants. One of there soils is Malibu organic living soil https://buildasoil.com/products/living-organic-soil-malibu-compost?variant=10193115717

 

[Old Piney]

Some times it just doesn't matter so there's spots. I've had some plants that are just wrecked with spots but that's just a few individuals I cull them out as they should be. I grow in soaking wet NJ and always got some spots, mostly late when who cares. Don't use fungicides, copper , neem oil etc that's just nasty. The solution is selection ,spots are everywhere when you grow in the wet.
“Give me spots on my apples
But leave me the birds and the bees
Please!”

 

[goriillaunit]

The number one cause of outdoor plant disease is planting plants too deep in the soil and in the wrong soil porosity or soil drainage. Not just cannabis plants but any woody stem plants. When you plant too deep in soil that doesn't drain you will get leaf spot, stem rot, bud rot, mold, or any other common fungal diseases. The reason is the plant has long periods of setting in wet soil. You can spray fungicide all you want but it won't change the fact the plant is setting in water.

If you raise the soil a good 12 inches where the soil is wet and only grow in good draining soil you won't have problems with any kind of fungal diseases. It's not the plants it's the grower and where and how the plant is planted that causes the problem with leaf spot. When I see the plants above in the photos I see plants that are too deep in the ground and planted in wet soil. The only way a pathogen can enter a plant is thru soggy wood.

I would disagree that a plant planted too deep will be more vulnerable to this disease. Maybe only in some small percentage. Take a peek at my diary and see how I have my plants planted. I do everything on organic fertilizers. I have spots in a clay area and this problem does not occur there.

 

[Creeperpark]

I would disagree that a plant planted too deep will be more vulnerable to this disease. Maybe only in some small percentage. Take a peek at my diary and see how I have my plants planted. I do everything on organic fertilizers. I have spots in a clay area and this problem does not occur there.

There are always exceptions to every rule. All gardens are governed by conditions not always by the growers.

 

[goriillaunit]

There are always exceptions to every rule. All gardens are governed by conditions not always by the growers.

Only on the rest where I have more moisture this problem occurs, yes this substrate have permeable, buy earth and coconut fiber so it is loose. This is the worst infestation I know of....