Is this white powdery mildew, damping off, or something else?

[ripsix]

I've never seen this before. These are both in the same Earthbox (no water in bottom), all soil is BuildASoil Light Recipe and the only thing I've added was some BuildASoil Worm Castings and 1 watering of rootwise as I was putting the soil in. I planted the seeds straight into the soil, since they're autoflowers.

Indoor tent organic grow, lights at 18/6, everyday has been about 79°F / 68% humidity (with a humidifier and exhale co2 bag).

The seedlings were fine as they sprouted, except the one was already drooping - it didn't look broken and searches led me to thinking it was 'damping-off disease'. But then after putting them under seedling domes for 1 day, this white fuzz appeared around the both of them

 

[DARKSIDER]

Looks a lot like powdery mildew at a guess i would say yes. Hopefully others will comment too.
CORRECTION MOLD MAYBES AS STATED BY chilliwilli.

 

[chilliwilli]

I think this is mold. The seed dome helped grow by raising the rh%. Pm looks more like flour or dusty and not fuzzy like this. But i'm no expert in pm and only know it first hand indoors

 

[ripsix]

I was hoping it was some harmless or beneficial fungus from being a living soil, first living soil / organic grow I've attempted.

 

[tobedetermined]

I think this is mold. The seed dome helped grow by raising the rh%. Pm looks more like flour or dusty and not fuzzy like this. But i'm no expert in pm and only know it first hand indoors

I agree. I would say mold - not mildew.

 

[Sasult]

It's a mold, good or bad I can't say. With what you added I would guess good, but still warm it up and back off the moisture. I don't like where it is at though, so I would clean it off with a Qtip and some peroxide.

 

[DARKSIDER]

I stand corrected mold it is maybes heres a similar photo to what youre showing

 

[ripsix]

I took the domes off and few hours later they were completely dead. Seemed to mimic damping off disease in that respect.

I just tilled up the first 6 inches of soul and it's not overly moist and planted 2 more seeds in their place. Figure even if the same mold appears and they die, I can rule out damping off disease.

 

[Dime]

I stand corrected mold it is heres a similar photo to what youre showing
View attachment 18822257

Sprinkle cinnamon on the mold

 

[Creeperpark]

Its mushroom mycelium in the soil and it won't hurt anything. The fuss on the stem is herbaceous stem hairs and it won't hurt anything. IF you start your seeds in dixie cups it will be easier to manage the watering. If you are getting damping off disease it's from over-watering or soggy soil. Don't use domes to germinate seeds because it's too wet and they will fail after they sprout.

Using dixie cups you can weigh the cups before watering and after watering and write the weights on the top of the cup for the best water management. Go to the propagation forum and read the surefire method. 100% guarantee no seed lost every.

 

[Creeperpark]

I was hoping it was some harmless or beneficial fungus from being a living soil, first living soil / organic grow I've attempted.

It is good and it won't hurt anything, it is just mushroom mycelium from the organic matter in the mix.

 

[LostTribe]

I also think it is mycelium and not to worry about it. I don't cover my seedlings at all just make sure to keep them from drying out too bad. They like wet and dry cycles just be careful not to get them too wet or too dry.

Pro Tip: Get used to picking them up as the weight will teach you when to water. Unless you are in coco. I still havent figured out coco in veg whatsoever. I am probably going to use promix in cups and transplant into coco/perlite from now on. I give up.

 

[acespicoli]

I've never seen this before. These are both in the same Earthbox (no water in bottom), all soil is BuildASoil Light Recipe and the only thing I've added was some BuildASoil Worm Castings and 1 watering of rootwise as I was putting the soil in. I planted the seeds straight into the soil, since they're autoflowers.

Indoor tent organic grow, lights at 18/6, everyday has been about 79°F / 68% humidity (with a humidifier and exhale co2 bag).

The seedlings were fine as they sprouted, except the one was already drooping - it didn't look broken and searches led me to thinking it was 'damping-off disease'. But then after putting them under seedling domes for 1 day, this white fuzz appeared around the both of them

over watering ? temp is getting high and humidity is high
I would prefer to see the temp around 70F and the humidity 35-40
Ditch the humidifier for now, set your fan on a temp humidity switch to vent outside?
Whats your ambient humidity outside your tent ? Do you have clip on oscillating fans or similar?

Parasitic and pathogenic fungi form symbiotic relationships with other living organisms, similarly to mycorrhizal fungi; however, they benefit to the detriment (and sometimes death) of their host. Many species affect trees and other plants. Others attack mushrooms, sometimes rendering the host species unrecognizable.

Sterile soil is a great idea till your plants get true leaves and are strong enough to resist disease

Dew point - Wikipedia

en.wikipedia.org

Yeah its always ready to rain in your environment ?
control the dew point of the air in a building or in a smaller space for a manufacturing process.

Dew point	Relative humidity at 32 °C (90 °F)
Over 27 °C	Over 80 °F	73% and higher
24–26 °C	75–79 °F	62–72%
21–24 °C	70–74 °F	52–61%
18–21 °C	65–69 °F	44–51%
16–18 °C	60–64 °F	37–43%
13–16 °C	55–59 °F	31–36%
10–12 °C	50–54 °F	26–30%
Under 10 °C	Under 50 °F	25% and lower

I use a vented dome until the seed breaks surface then no dome spray bottle wet substrate till the seedling is full emerged as needed to prevent drying dry substrate is very hard to displace during emergence.
Powdery mildew will look like a grey veins and powder on the leaves

most people dont appreciate the benefits of sulfur its truly under utilized in hobby grows

https://files.plytix.com/api/v1.1/file/public_files/pim/private/assets/43/37/8d/5e/5e8d3743202d9eba64d3af60/texts/84/93/42/60/60429384d92bc09f9b6cf738/l141.pdf

^^^directions for use^^^

Take some of that soil and bake it in the oven at 250F for 30min and put it in solo keg cups with drain holes
Or your gonna waste some seeds, when you get a few sets of leaves continue as you wish with your reg soil.
Just keep it a little drier low temp = low humidity best luck I drop seeds in distilled water for 24 hours,
2 part water 1 part 3% peroxide h202 is good as well, better than water it stimulates germination
misc reading cultivation notes

 

[LostTribe]

over watering ? temp is getting high and humidity is high
I would prefer to see the temp around 70F and the humidity 35-40
Ditch the humidifier for now, set your fan on a temp humidity switch to vent outside?
Whats your ambient humidity outside your tent ? Do you have clip on oscillating fans or similar?

Parasitic and pathogenic fungi form symbiotic relationships with other living organisms, similarly to mycorrhizal fungi; however, they benefit to the detriment (and sometimes death) of their host. Many species affect trees and other plants. Others attack mushrooms, sometimes rendering the host species unrecognizable.

Sterile soil is a great idea till your plants get true leaves and are strong enough to resist disease

Dew point - Wikipedia

en.wikipedia.org

Yeah its always ready to rain in your environment ?
control the dew point of the air in a building or in a smaller space for a manufacturing process.

Dew point	Relative humidity at 32 °C (90 °F)
Over 27 °C	Over 80 °F	73% and higher
24–26 °C	75–79 °F	62–72%
21–24 °C	70–74 °F	52–61%
18–21 °C	65–69 °F	44–51%
16–18 °C	60–64 °F	37–43%
13–16 °C	55–59 °F	31–36%
10–12 °C	50–54 °F	26–30%
Under 10 °C	Under 50 °F	25% and lower

I use a vented dome until the seed breaks surface then no dome spray bottle wet substrate till the seedling is full emerged as needed to prevent drying dry substrate is very hard to displace during emergence.
Powdery mildew will look like a grey veins and powder on the leaves
View attachment 18824659
View attachment 18824661
most people dont appreciate the benefits of sulfur its truly under utilized in hobby grows

https://files.plytix.com/api/v1.1/file/public_files/pim/private/assets/43/37/8d/5e/5e8d3743202d9eba64d3af60/texts/84/93/42/60/60429384d92bc09f9b6cf738/l141.pdf

^^^directions for use^^^

Take some of that soil and bake it in the oven at 250F for 30min and put it in solo keg cups with drain holes
Or your gonna waste some seeds, when you get a few sets of leaves continue as you wish with your reg soil.
Just keep it a little drier low temp = low humidity best luck I drop seeds in distilled water for 24 hours,
2 part water 1 part 3% peroxide h202 is good as well, better than water it stimulates germination
misc reading cultivation notes

I had a bit of an issue with PM and tried many things from sulfur to iso spray and everything in between. What finally kicked its ass was letting the plants get big enough to where the Potassium Silicate finally created cell walls that they could simply not break through.

Early on with seeds you don't need any nutrients as they dont require anything for 2-3 weeks of initial growth. Good post Ace!

 

[acespicoli]

White Mold: How to Diagnose and Prevent Sclerotinia in Cannabis​

What cultivators can do to prevent Sclerotinia and how they can mitigate when white mold becomes a problem.

Sarah Cochran, Lindsey Thiessen, Brian Whipker, Paul Cockson, Patrick Veazie and David Logan | May 2020

Photo by Brian Whipker
A recurring series focusing on plant cultivation by university researchers
A wide assortment of insects and diseases, including white mold, find Cannabis sativa to be a suitable host. White mold is a disease caused by the pathogen Sclerotinia sp. While Sclerotinia sp. infections in outdoor cultivation are fairly common, incidences during indoor and greenhouse are rare.

What is white mold?​

Sclerotinia sclerotiorum, commonly called white mold, is a pathogen that causes crown, root and stem rot, and has a host range of more than 400 plant species, according to the 2007 article “White mold (Sclerotinia),” written by Virginia Heffer Link and Kenneth B. Johnson of Oregon State University.
White mold has been reported in cannabis propagation and could be a cause for concern in growing operations. The fungus survives between growing seasons inside infected plants or in soil residue as hard, black resting structures called sclerotia (Fig. 1). These surviving sclerotia are the primary inoculum to infect the subsequent year’s crop. In a near-saturated, cool soil environment, sclerotia germinate and release spores through cup-like structures called apothecia to infect plant tissue. According to Heffer Link and Johnson, wet foliage or plant material in growing environments with temperatures of 54 to 75 degrees Fahrenheit (12 to 24 degrees Celsius) for one to two days can lead to spore germination, giving rise to infection.
Macroscopic Characteristics Sclerotinia species can be macroscopically identified by the white, cotton-like mycelium (Fig. 5) that can be present on the above-ground plant tissues two to four days after introduction when the spore lands. The mycelium produces enzymes, which cause water-soaked lesions on infected tissue. As the disease progresses, the mycelium clumps, eventually becoming the black, hardened sclerotia (Fig. 6). Stem bleaching and stem lodging (buckling) are also common symptoms of S. sclerotiorum infection, especially in hosts such as tomatoes. Older tissues, especially stems, may appear bleached and shredded with black, irregularly shaped sclerotia inside the dead tissue. White mold is a monocyclic disease, meaning it will not produce spores within the same growing season in which it infects plant tissue. Plant-to-plant spread of disease in the field is rare, but during high-density production in indoor or greenhouse-growing environments, it is possible.

Figure 1. Sclerotinia sclerotiorum survives between growing seasons inside infected plants or in soil residue as hard, black resting structures called sclerotia. Figure 2. Sclerotinia sclerotiorum can produce lesions on the roots, stem, leaves, petioles and flowers. Figure 3. In moist environments, a white webbing of fungal hyphae (mycelium) can be seen on infected plant tissue. Figure 4. Mycelium growth can also infect adjacent plants in propagation trays. Figure 5. Sclerotinia sclerotiorum cultures with mycelium (white, fluffy fungal growth) expanding on a petri dish (left) and sclerotia (black, irregularly shaped overwintering structures) forming on an older colony (right). Figure 6. Three developmental stages of S. sclerotiorum sclerotia: aggregating hyphae (1), fully developed sclerotium (2) and immature, developing sclerotium (3).
Photos 1-4 by Brian Whipker; Photos 5-6 by Sarah Cochran

11 White Mold Management Options​

Many disease management strategies exist, and when these practices are combined with an integrated pest management strategy, they can provide good control of white mold. In growing operations, these cultural practices are an integral part of disease management.

1. Control moisture and humidity. These are the first steps in preventing or limiting white mold outbreaks. High humidity and moisture create a favorable environment for the pathogen and can lead to disease outbreaks.
2. Employ proper air flow and spacing between plants to decrease humidity levels.
3. Prune plants that have significant canopy growth to improve air movement.
4. Create proper spacing so that plant canopies do not overlap, which could allow for disease to spread throughout the environment.
5. Utilize drip irrigation and/or minimize the amount of overhead watering to help reduce excess moisture.
6. Develop proper sanitation practices to limit disease pressure such as sterilizing substrate and other cultivation materials, avoiding growing plants in areas with a previous history of white mold, and managing weeds.
7. Screen and clean seeds before planting to ensure that any seed-like black sclerotia are not introduced into the growing environment. The inspection process is akin to sifting through dry beans and lentils to be sure there are no stones before cooking.
8. Keep an eye on your ventilation. In the case of the white mold outbreak observed in cannabis propagation, it is thought that the sclerotia outside the growing environment produced apothecia (fruiting bodies), which then released spores that entered the environment though the vents or cool cells.
9. Implementing biological control, such as spraying Coniothyrium minitans spores on soil, has shown efficacy when used in an integrated pest management system for limiting disease. Because C. minitans is a living organism, cultivators must provide adequate time for it to establish and proliferate, and the application of this organism does not ensure that all sclerotia will be destroyed.
10. Try to catch it early. As the pathogen infects and spreads throughout the host tissue, fungicides and biocontrol options for Sclerotinia control are not registered, nor effective.
11. Discard infected plants as a primary control option. For propagation trays, also discard potentially contaminated, adjacent clones to avoid introducing the disease into your growing room or production fields.

White mold outbreaks during propagation can introduce the disease during production. Given the long-term survivability of sclerotia, the disease can persist for several years. Thus, identification and management of the disease is the best long-term strategy.
Sarah Cochran is a master's student in the Department of Entomology and Plant Pathology at North Carolina State University (NCSU); Dr. Lindsey Thiessen is an assistant professor of plant pathology at NCSU; Dr. Brian Whipker is professor of floriculture, Department of Horticultural Science, NCSU; Paul Cockson is a graduate research and teaching assistant at NCSU; Patrick Veazie and David Logan are undergraduate research assistants at NCSU.

Sclerotinia sclerotiorum - Wikipedia

en.wikipedia.org

seed-like black sclerotia
See also: List of hemp diseases


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