Damping Off Fungus...

[Vegetation]

Hi,
I'm really confused. I like to grow vegetables. I have been told repeatedly that the dreaded damping off fungus that can kill emerging seedling is found in soil. As I have had quite some trouble with this phenomenon, I decided to sprout seeds in sterile paper towel in sterile sealed bags (as I have seen many people do with success) with the idea of transplanting them from there to sterile soil in containers indoors before subjecting the resultant plants to the pests and fungi of outdoor soil at such a date when they are much larger and more established and able to better cope. Much to my chagrin, I have found the same dreaded white fungus growing in my bags within 2.5 days of sealing them with the seeds inside. This is not just happening with one batch of seeds. This is happening with nearly ALL my seeds of dozens of varieties of unrelated plants from multiple different sources. My questions are 1. How is this possible and where are these fungus spores really coming from if not the soil? and 2. How can I stop this ruining my seeds and therefore my gardening experience? Any help would be greatly appreciated. Thankyou in advance.

 

[Zelda]

I have always started my seeds in trays in regular potting soil. After germination, seeds need air circulation to prevent damping off. If they are sealed in a bag with no air circulation and are constantly wet, they will not survive.

 

[Chuck]

Hi,
I'm really confused. I like to grow vegetables. I have been told repeatedly that the dreaded damping off fungus that can kill emerging seedling is found in soil. As I have had quite some trouble with this phenomenon, I decided to sprout seeds in sterile paper towel in sterile sealed bags (as I have seen many people do with success) with the idea of transplanting them from there to sterile soil in containers indoors before subjecting the resultant plants to the pests and fungi of outdoor soil at such a date when they are much larger and more established and able to better cope. Much to my chagrin, I have found the same dreaded white fungus growing in my bags within 2.5 days of sealing them with the seeds inside. This is not just happening with one batch of seeds. This is happening with nearly ALL my seeds of dozens of varieties of unrelated plants from multiple different sources. My questions are 1. How is this possible and where are these fungus spores really coming from if not the soil? and 2. How can I stop this ruining my seeds and therefore my gardening experience? Any help would be greatly appreciated. Thankyou in advance.

I have been growing all of my vegetables from seed for many years and here in South Texas damping off is a very serious problem. Whether sterile soil is a stop to this disease is debatable as the fungal spores are also in the air. What I have found to be the best solution is to sterilize the soil first and then add horticultural cornmeal. I just get my unsterilized homemade compost and cook it in the oven for 20 minutes @ 200F. I use a meat thermometer to let me know the temp. After the soil cools I add about 10% by volume the cornmeal and THOROUGHLY mix it together and almost fill my planting container with it. I then saturate the soil, let it drain and plant at least 2 seeds in each container and then cover up the seeds with my sterilized compost. Here is the most important part. As soon as the seed sprouts and the seedling emerges sprinkle enough cornmeal so as to cover the soil.

Why horticultural cornmeal and what does it do? HC is the best growing medium for a beneficial fungus called Tricoderma. Tricoderma kills the damping off fungus. Tricoderma looks like a stringy mass of cobwebs.

There are other methods that also work but IMO not nearly as well. One method is to spray a tablespoon of hydrogen peroxide per quart of water on the newly emerged seedlings. Another is to spray a tablespoon of baking soda per quart of water. I have used both methods but I have had much better luck with the cornmeal.

 

[Rajesh Sethi]

Hi!,
you need to do
1) just clean the seeds with CuSO4 solution or any fungicide followed by cleaning with H2O2( hydrogen peroxide solution) .
2) use sterilized water, add few drops of H2O2(peroxide solution) to soak paper towel
3) make sure that paper towel is clean, not exposed


Spores are everywhere, if the plant seeds do not germinate fast, others (fungi, molds, even pest) will grow on it.

 

[Rajesh Sethi]

Buying good seeds is important, as seeds may be from plant that has infection(spore, virus), or insect Invasion (eggs) or old seed stock

 

[Owdboggy]

Try spraying the emerging seedlings with Cinnamon dissolved in a little water.

 

[Vegetation]

Hi, Thanks so much for your help and suggestions everyone. What an amazingly friendly, helpful and knowledgeable community! I'm very glad I have joined. I will stop germinating in bags and I will give all your suggestions a go. Chuck, when you refer to cornmeal, is that the same thing as polenta? I think that might be what we call it in Australia... but I'm not sure if it's the same substance.

 

[Chuck]

Hi, Thanks so much for your help and suggestions everyone. What an amazingly friendly, helpful and knowledgeable community! I'm very glad I have joined. I will stop germinating in bags and I will give all your suggestions a go. Chuck, when you refer to cornmeal, is that the same thing as polenta? I think that might be what we call it in Australia... but I'm not sure if it's the same substance.

Polenta is a dish made from corn. As long as the polenta is not enriched it should work. At the grocery store you can buy either whole ground or stone ground corn which will also work just as long as it is not enriched. Horticultural corn meal is just a coarse ground dried corn used in animal feeds. Cornmeal doesn't do a thing for the plants themselves. All it does is provide a perfect habitat for tricoderma fungus to thrive. Google tricoderma and damping off. There is a lot of data available.

 

[headfullofbees]

I have been growing all of my vegetables from seed for many years and here in South Texas damping off is a very serious problem. Whether sterile soil is a stop to this disease is debatable as the fungal spores are also in the air. What I have found to be the best solution is to sterilize the soil first and then add horticultural cornmeal. I just get my unsterilized homemade compost and cook it in the oven for 20 minutes @ 200F. I use a meat thermometer to let me know the temp. After the soil cools I add about 10% by volume the cornmeal and THOROUGHLY mix it together and almost fill my planting container with it. I then saturate the soil, let it drain and plant at least 2 seeds in each container and then cover up the seeds with my sterilized compost. Here is the most important part. As soon as the seed sprouts and the seedling emerges sprinkle enough cornmeal so as to cover the soil.

Why horticultural cornmeal and what does it do? HC is the best growing medium for a beneficial fungus called Tricoderma. Tricoderma kills the damping off fungus. Tricoderma looks like a stringy mass of cobwebs.

There are other methods that also work but IMO not nearly as well. One method is to spray a tablespoon of hydrogen peroxide per quart of water on the newly emerged seedlings. Another is to spray a tablespoon of baking soda per quart of water. I have used both methods but I have had much better luck with the cornmeal.

Whilst I have no doubt as to the benefits of trichoderma, nor the use of cornmeal in propagation of such, it seems to me that the cornmeal is acting VERY quickly on the production of trichoderma.
Are you sure there isn't a benefit coming directly from the cornmeal?
Perhaps as a decoy?

 

[Chuck]

Whilst I have no doubt as to the benefits of trichoderma, nor the use of cornmeal in propagation of such, it seems to me that the cornmeal is acting VERY quickly on the production of trichoderma.
Are you sure there isn't a benefit coming directly from the cornmeal?
Perhaps as a decoy?

Cornmeal itself has a small beneficial NPK makeup. N = 1.6, P= .65 and K of .40. It also has 23% iron. IMO it would take a LOT of cornmeal to do much in the way of fertilizing. When I sprinkle cornmeal on the soil of my seedlings tricoderma is visible within 2 days. One bad thing about using cornmeal is that if you use too much it will cake and form an almost waterproof barrier. When mixing cornmeal into the soil before planting seeds I have found that 10% by volume is about right. Any more and the meal will start to cake. I guess it would depend upon your soil as to how much is too much.
For all of you out there who are not familiar with horticultural cornmeals there are two types: Corn Gluten Meal and Cornmeal. Corn Gluten Meal is used as a pre-emergent herbicide. It works but is extremely time sensitive and it is also expensive. Cornmeal is available in 3 forms. Whole Ground, Stone Ground and Enriched. You do not want the Enriched as most of the physical properties of whole and stone ground have been polished away and these properties are what tricoderma likes to grow on.

 

[headfullofbees]

My thought was, that as cornmeal is nourishment for trichoderma, may other fungi, the ones responsible for damping off, also prefer the cornmeal to your seedlings.

Thoughts?

 

[Chuck]

My thought was, that as cornmeal is nourishment for trichoderma, may other fungi, the ones responsible for damping off, also prefer the cornmeal to your seedlings.

Thoughts?

I have often wondered the same thing. If tricoderma's favorite growing medium is cornmeal then why is it not the damping off fungi's as well? All I can say with certainty is that there are numerous fungi that lead to the growth of the damping off fungi such as Phythium, Fusarium, Alternaria and others. My opinion is that tricoderma, which is present in all soils and being a predator fungi, can reproduce much faster than the damping off fungi which must have certain requirements to exist. I have searched and searched for this answer to no avail. I have found that in some soils damping off fungi does not exist and why this happens I have not found an answer but there is tricoderma fungi present. Does this make a difference as to the lack of damping off? Answers are (IMO) not to be found.