Leaf Spot Fungas, what to do?

[Randm]

I cant post pictures at the moment, however my grow room, and plants have become infected with what appears to be leaf spot fungas. I've given my grow room a complete cleaning (twice to be sure) but it keeps reappearing.
So I did a bit of reasurch on the subject, and outside of trashing all my plants and completely sterilizing my grow area or starting over in a new grow area, there is no way of getting rid of it once it catches hold. I know all the preventative measures to take, ventilation etc, so I don't need info on that.
What I do need is info from someone who has successfully fought this infestation and what products, or procedures they used to fight it.
I grow indoors in soil (foxfarm and Organic Roots ) .
All plants are currently in veg, none in flower.
I've been treating with Seranade as well as the backing soda spray, with limited success, they both seem to slow it down, but don't kill it. I have heard that it is a good idea to rotate treatments as the Fungas can become resistant to just one kind of treatment.
I do have some sulfer for running a sulfer burner being shipped to me. I should have it in a few days and will be giving that a try.
I have had a hard time finding info on this kind of disease, any experts out there?
Can you use a sulfer burner with plants in the room? Will the sulfer hurt or damage them?
Heck I'm getting a mite desperate here, even considering a UV-C lamp.

 

[mellokitty]

leaf spot is relatively rare indoors..... what colour is it?

 

[Randm]

Leaf spot is a generic term used to describe a number of related molds, as for color, mostly brown. It presents itself first in the larger, older fan leaves, causing them to have 'dead spots' or brown blotches, which if left unchecked it will destroy the leaf, and subsequently your entire plant will suffer and die. I've even had it appear on the first real leaves of seedlings. ( And no, this is not a nitrogen problem, already been through the usual suspects). It is a systemic fungas, which gets into the cellular structure of the plant and attacks from within.

The problem I have found, is in identifying it in the first place. It is real easy to mistake this as a nutriant problem, such as lockout or nitrogen diffeciancy, as the appearance is very much identical in most respects. It also is not a result of overwatering, such as in a root problem resulting from to much moisture in the soil, which again has some similarities in appearance.

I just sprayed with a copper based fungaside, and removed all the affected leaves. I sure hope that has some results. I'll post if I find a solution to this stuff.

 

[Randm]

Pictured are White Rhino and Master Kush. The Seedlings are Master Kush and the rest are White Rhino.
Sorry about the poor quality of the pictures, still getting used to the new camera.

 

[neved]

Its like cal/mag def ... and you have root bond ....Why u didnt put them to bigger pot s?

 

[Randm]

Its like cal/mag def ... and you have root bond ....Why u didnt put them to bigger pot s?

Ya gotta be kidding neved, those seedlings just popped and won't be ready for another pot for a couple of weeks and the others where transplanted two weeks ago. You don't think I checked the roots already?. Its like I said in my previous posts, Fungal attacks can look a lot like a number of other issues, which I have been diligantly addressing. I don't need advice on nutriants, cal/mag, etc. What I DO need is advice from people who have fought the fungas and won. This is a fungal attack, nothing more, nothing less.
One of the primary reasons I am posting this thread, outside of seaking a real solution, is that when I was searching for what was wrong with my plants I could find very little info on fungal attacks. Everybody knows about powder mildew and bud rot, and info on those can be found anywhere. What I could not find was pictures, articles, and real info on the hundreds of other fungi that also can affect your crop.
It seemed that 90% of those that responded to my posts all said the same things. Cal/mag, or Nute lockout, or root rot. Those where the first things I addressed in my search for a cure. I lost an entire crop because of being misdirected into thinking that it was a nutritianal, enviromental, lighting, or another cause. When in fact it turned out to be a fungal attack.

 

[mellokitty]

this is an outdoor thread, but there's some mention of leaf spot indoors in there too...... failing that, trystnhawk is very helpful and approachable, try shooting him a pm.....

https://www.rollitup.org/outdoor-growing/453514-guerrilla-growers-nightmare-leaf-spot.html

hope this helps, i've only ever had it outdoors on my roses.

 

[ismokealotofpot]

Have you tried cal mag plus. plain epsom salt will not work because you need calcium to absorb mg most fertilizer does not have calcium in it. You can grind up egg shells put them in water and feed with it if you have a problem with calmag. looks a fertizer burned also, just a little. If you like to panic look into tobacco mosaic virus. Do you smoke tobacco?

 

[ismokealotofpot]

this is leaf spotLeaf spots are round blemishes found on the leaves of many species of plants, mostly caused by parasitic fungi or bacteria.A typical spot is "zonal", meaning it has a definite edge and often has a darker border. When lots of spots are present, they can grow together and become a blight or a blotch. Fungal spots are usually round or free-form in shape.
In most cases, leaf spots are considered to be only a cosmetic problem, but they can have economic effects on nurseries or infloriculture.

 

[ismokealotofpot]

You do not have leaf spot. So stop jumping on peoples case when they try to help you!

 

[supchaka]

It doesn't look like brown leaf spot that I have dealt with. If it is then using a copper based fungicide as well as removing what affected leaves can be safely removed has worked for me in the past. The couple pics of seedlings you have lead me to believe something in the soil is burning the plants, they are too new IMO to be affected by BLS.

 

[Randm]

It doesn't look like brown leaf spot that I have dealt with. If it is then using a copper based fungicide as well as removing what affected leaves can be safely removed has worked for me in the past. The couple pics of seedlings you have lead me to believe something in the soil is burning the plants, they are too new IMO to be affected by BLS.

The first time I noticed this problem, I changed to a different soil. From Fox farm to organic roots 707.

 

[Randm]

Have you tried cal mag plus. plain epsom salt will not work because you need calcium to absorb mg most fertilizer does not have calcium in it. You can grind up egg shells put them in water and feed with it if you have a problem with calmag. looks a fertizer burned also, just a little. If you like to panic look into tobacco mosaic virus. Do you smoke tobacco?

The little ones have never had ferts, as they are too young. The soil is roots 707 ( had the same thing happen with fox farm) From what I have seen about tobacco mosaic virus is that it causes a blistering on the leaves. At least from the pictures I have seen. I havent completely ruled anything out yet, and I may be wrong on the fungas variety, but I am convinced that it is a fungas that I am dealing with here ( possibly a virus, but I haven't seen anything that shows that to be the case yet)

I'll go ahead and pick up a bottle of calmag+ next time I am at the hydro store and give that a try.

Let me give a little history of what I've done here. When it first started showing up I had some THC bomb that I was growing from seed. It showed up just after I switched to 12/12.
I tryed different nute regimes, flushing multiple times, using cal/mag ( not calmag+, didn't know about that one) even replaced all the HPS bulbs in my grow room.
When I finally trashed the THC Bomb, as they where devastated by the "Borg". I cleaned and disenfected both my grow and my flower room with bleach and soap. I gave every utinsil, pot and tool a complete disinfecting. Everything was as clean as I could possibly get it. New air intake filters as well.
Nothing entered the room without being clean first.
I bought brand new bags of soil and threw out the open bag, figuring that maybe a pathogen got in there.
I filtered the water as well ( well water, 7.0 ph).
I popped some new seeds, and within weeks I was seeing the ugly signs again. I was going nuts, as in the years I have been growing I have never encountered anything like this.
I have never seen a seedling show this kind of problem befor. I've seen the results of overwatering/ underwatering on seedlings but they are much too young to be suffering from some kind of deficiancy. Thats one of the reasons I went with another brand of soil, to eliminate the possibility that maybe my soil was too 'hot' for young ones, even though I've had many successful grows in the same foxfarm soil, using the same methods.
There is the possibility that I have some kind of pathogen in my water supply, and should take a sample in to be tested. If I can't get a handle on it soon then thats my next step.
Thanks for replying to my posts, I do appreciate it and I don't mean to sound testy, but my frustration factor is red lined.

 

[Randm]

It doesn't look like brown leaf spot that I have dealt with. If it is then using a copper based fungicide as well as removing what affected leaves can be safely removed has worked for me in the past. The couple pics of seedlings you have lead me to believe something in the soil is burning the plants, they are too new IMO to be affected by BLS.

Unless the 'whatever it is' somehow got into the soil? Brand new bag though.
I treated this morning with a copper based fungaside, I'll give it a few days and see what that does.
I also started some of Nirvanas ICE seeds this morning, using the paper towel method. I sprayed a little of the copper based fungaside on the paper towel in the hopes that if it is in/on the seeds, or water, that it would kill any spores. I will be keeping these isolated from my other plants and see how they progress.

Thanks again for your interest and for your advice. I'll figure this thing out yet.

 

[ismokealotofpot]

botanicare cal-mag plus thats the good stuff.

its about 15 bucks for a quart but it lasts a long time. one teaspoon per gallon of water.
if your using ro water then you have no trace minerals in the water. I have well water and still need it. I kept getting this chlorosis look then spots then leaves were dropping off so I used epsom salt thinking I was lacking magnesium turned out to be calcium def causing the magnesium lockout. After two weeks everything looked green again or at least getting better.

 

[ismokealotofpot]

 

[Randm]

botanicare cal-mag plus thats the good stuff.

its about 15 bucks for a quart but it lasts a long time. one teaspoon per gallon of water.
if your using ro water then you have no trace minerals in the water. I have well water and still need it. I kept getting this chlorosis look then spots then leaves were dropping off so I used epsom salt thinking I was lacking magnesium turned out to be calcium def causing the magnesium lockout. After two weeks everything looked green again or at least getting better.

Thanks, sounds like the kind of advice I need to hear, I did try epsom salts, with no results. I think I'll pick up a quart tomorrow when I go into town.

 

[Randm]

Fungi: At least 88 species of fungi attack Cannabis and more are being discovered every year (McPartland & Hughes 1994, McPartland & Cubeta 1996). By far the most significant is gray mold, caused by Botrytis cinerea (teleomorph Botryotinia fuckeliana). B. cinerea thrives in temperate regions with high humidity and cool to moderate temperatures. Under these conditions gray mold can reach epidemic proportions and completely destroy a Cannabis crop within a week (Barloy & Pelhate 1962). B. cinerea attacks many crop plants and weed species worldwide.
Gray mold presents in three scenarios, depending on plant maturity and cultivar. Seedlings succumb to damping off, discussed below. In fiber cultivars gray mold presents as a stem disease. It arises as a gray-brown mat of mycelium which becomes covered by masses of conidia (fungal spores). Stems become chlorotic at margins of the mat. Enzymes released by B. cinerea reduce stems to soft shredded cankers. Stems often snap at canker sites. Gray mold may encircle and girdle stems, wilting everything above the canker. Fiber varieties become more susceptible after canopy closure. In field experiments in the Netherlands the disease was found from the beginning of July (Van der Werf and Van Geel, 1994). Van der Werf et al. (1995) note Hungarian Kompolti Hibrid TC is more susceptible to gray mold than other fiber varieties. Dempsey (1975) says the Russian cultivars JUS-1 and JUS-7 are resistant, but these may no longer be available (de Meijer 1995).
In drug cultivars, gray mold infests flowering tops. Large moisture-retaining female buds are most susceptible. Fan leaflets first turn yellow and wilt, then pistils begin to brown. Whole inflorescences soon become enveloped in a fuzzy gray mycelium then degrade into a gray-brown slime. Drug varieties are most susceptible during flowering near harvest time. Dense tightly-packed buds of Cannabis afghanica Clarke tend to hold moisture and easily rot (Clarke 1987). Afghan cultivars evolved in very arid conditions and have no resistance to gray mold. This unfavorable trait is often expressed in hybrids that have only a small percentage of C. afghanica Clarke heritage.
For the second most important disease, Termorshuizen (1991) lists hemp canker. This diease is caused by Sclerotinia sclerotiorum. The fungus primarily attacks fiber cultivars in Europe, but it has caused up to 40% losses in North America (Hockey 1927) and damaged hemp in Australia (Synnott 1941) and Tasmania (Lisson & Mendham 1995). Hemp canker has also appeared on drug cultivars in India (Bilgrami et al. 1981). Symptoms begin as watersoaked lesions on stems and branches of plants nearing maturity. The lesions collapse into cankers and become darkly discolored. Affected areas take on a shredded appearance and the pith becomes filled with a white cottony mycelium. Plants remain in this condition or wilt and fall over. By September large black sclerotia develop on the stem surface or within pith of dead stalks.
Damping off fungi kill seeds in soil or seedlings shortly after they emerge from the soil. Fungi invade stems of seedlings at the soil line, causing a brown watery soft rot, then the plants topple over. Most damping off is caused by two Protoctistan Pythium species (technically they are o–mycetes, not fungi), P. aphanidermatum and P. ultimum. Several fungi also cause damping off—Rhizoctonia solani, Botrytis cinerea, Macrophomina phaseolina, and several Fusarium species, F. solani, F. oxysporum, F. sulphurem, F. avenaceum, F. graminearum. Together they make damping off a ubiquitous problem, attacking all cultivars of Cannabis (Bush Doctor 1985).
The two most common leaf spot diseases are yellow leaf spot caused by two Septoria species (McPartland 1995d), and brown leaf spot caused by about eight Phoma and Ascochyta species (McPartland 1995c). These diseases rarely kill plants but sharply reduce crop yields. Two common diseases of fiber varieties are downy mildew, caused by two Pseudoperonospora species, and olive leaf spot caused by a Pseudocercospora species and a Cercospora species. Pink rot, caused by Trichothecium roseum, has recently killed greenhouse-grown drug cultivars and seems to be on the rise. Less frequently seen but equally virulent diseases include brown blight (caused by two Alternaria and two Stemphylium species), anthracnose (caused by two Colletotrichum species) and white leaf spot (caused by Phomopsis ganjae). Powdery mildews, black mildews, and rusts are caused by high-visibility fungi, but rarely cause serious problems (McPartland 1983).
Some leaf disease fungi also infest stems, especially Trichothecium roseum, Phoma, Stemphylium, Colletotrichum, and Phomopsis species. The most serious causes of stem cankers are Fusarium species—F. graminearum and F. avenaceum occur in cooler climates, F. sulphureum and F. sambucinum in warmer climates.
Some root rots cause serious losses. Barloy & Pelhate (1962) considered root rot caused by Fusarium solani the worst disease of hemp in France. Pandotra & Sastry (1967) report a virulent strain of Rhizoctonia solani destroying 80% of drug plants in northern India. Root rot by Sclerotium rolfsii predominates in southern temperate zones and the tropics, on both fiber and drug cultivars (Ferri 1961).
Above-ground symptoms of root rots are hard to distinguish from wilt diseases. Three wilt diseases are important—fusarium wilt caused by two forms of Fusarium oxysporum, verticillium wilt caused by two Verticillium species, and premature wilt (also called charcoal rot) caused by Macrophomina phaseolina. Fusarium wilt received attention as a potential biocontrol to eliminate illegal marijuana plantations (Hildebrand & McCain 1978, Noviello et al. 1990). Wilt diseases are more severe in Cannabis fields harboring root-wounding nematodes or broomrape.

 

[Randm]

Update on mystery Fungal attack:
I found a copper based anti fungal solution and applied it to all my plants. I also cranked up my home made sulfur vaporizor. The copper based stuff seems to be the ticket so far. I applied it day befor yesterday and have definately seen a slowdown of the infestation. Not a complete stop, but a managable slowdown in its progression. I don't want to overdo it and harm my plants ( any more than they already are ) so I figured I would wait a few days for a repeat application. I only had to remove about a half dozen damaged leaves today, which is a heck of a lot better than it was. I may not have a cure yet, but at least I've got a handle on treating my poor babies.

Thanks for all the input and feedback. I really appreciate it.

 

[frettfreak]

Man, i am interested to see what actually fixes this for you but i have to agree, this doesnt look like leaf spot or a fungus to me. Looks like calcium def. plain and simple IMO.

I may have missed it, but are you using RO water by any chance?