What is Damping Off in Plants?

Damping Off Disease is one of the most common problems associated with plant seedling failure.  Damping off causes the rotting of young plant stems and roots.  It can occur both before and after seed germination.  It is caused by a combination of different environmental conditions, pathogenic fungi, and is most likely to occur in over wet, cool soil conditions.

There are many methods that have been used in order to prevent damping off from occurring.  With the many different pathogenic fungi and microbes that cause this condition, there is not one tried and true method to completely prevent it. 

Young seedlings that have been infected will have a stem that becomes extremely thin, like it has been pinched.  Within a matter of days, the new plants leaves will yellow, and the plant will fall over and die.  This is what happens if the plant germinates at all.  Many times seeds will already have, or will be infected by a pathogen from the soil.  This will cause the seed to not germinate at all.  The biggest issue with damping off is in its prevention.  This is because once the symptoms are realized, there is really no way for a plant to recover.  

How to Prevent Damping Off

So how do you control damping off disease?  That depends on your growing setup and other factors.  The following list shows the methods that can be used in part or in combination to ensure you have a successful grow:

• Proper Soil Management – Start with a quality seed starting mix.  We recommend using a light blend of peat and/or coco coir, some form of aeration (perlite/pumice), compost (Vermicast), and select beneficial microbials.  This will ensure good plant nutrition, proper drainage and water holding capacity, and beneficial microbes to encourage a healthy soil.
• Clean, Sterile Growing Containers and Tools -You want to use clean, sterilized containers where any possible pathogens have been destroyed.  Using clean tools and equipment not only suppresses disease and prevents contamination across different locations and plant varieties.
• Keeping Soil Evenly Moist – Pathogenic Fungi prefer certain conditions to multiply and attack plants.  Having a soil that remains too wet or too dry will encourage the growth of pathogens.  There are specific plant pests that prefer these conditions, so maintaining a consistent moisture level is key.
• Soil Temperature – Follow the best management practices for what you are growing.  Keeping the temperature at a preferred level for your plants will help with rapid germination and growth.
• Proper Air Flow – Maintaining a constant movement of air in and around your seedlings directly inhibits the growth of pathogenic fungi.
• Fungicides – The use of fungicides have also been used to suppress damping off disease.  The trade-off with this approach, however, is the possible loss of beneficial fungi and bacteria in the soil.  Thus being an overall detriment to complete soil health and vitality.

Biological Control of Root Pathogens

Therin lies the beauty of Beneficial Bacteria for plants.  These beneficial bacteria are also referred to as Plant Growth Promoting Rhizobacteria (PGPR).  The knowledge of just how powerful Beneficial Bacteria can be to soil and plant health is beginning to be realized.  Numerous scientific studies are showing that specific strains of bacteria and fungi are effective in combating not only damping off, but many other soil borne pathogens as well.

These scientific advances are beginning to show another way to not only protect soil, plants, and crops, but also increase production and yields along with it.  All in a natural way, without the need for chemicals or synthetics.

Specifically for damping off, the many pathogens involved makes it difficult to pinpoint a single one size fits all approach to treatment.  Some of the more common pathogenic fungi that cause damping off include Pythium, Fusarium, Rhizoctonia, and Sclerotium.  These fungi show different symptoms, and affect seeds and seedlings in different ways.

For example, Pythium is a considerable soil borne pathogen that can cause damping off both pre and post-emergence.  Scientific studies have shown that inoculation of seeds and seedlings with beneficial bacteria has a significant impact in the incidence of the disease<1>.  Beneficial fungi like Trichoderma, and bacteria such as Bacillus, and Pseudomonas have all been shown to be effective in the defense damping of caused by Pythium.  These beneficials out-compete and destroy the Pythium pathogen.

A major study conducted by BIOCOMES (www.biocomes.eu) and co-funded by the European Union looked at the biological control of Fusarium.  It found that the beneficial fungi, Trichoderma harzianum, was effective in resisting the Fusarium blight.  By using proper sowing practices, crop rotation, and land preparation, in conjunction with T. harzianum application, represented an effective means to better crop production and resistance to disease and blight.  Bacillus amyloliquefaciens, Bacillus pumilus, and various others have also been shown to be a control mechanism against Fusarium wilt<4>.

Separate studies have shown numerous other Bacillus, Trichoderma, Streptomyces, and Pseudomonas species to be effective biological control agents; in defense of pathogens such as Rhizoctonia and Sclerotium<2,3>.

But with all of these differing pathogens, and a variety of biological treatment methods, how to know which one to use?  The answer lies in the diversity of beneficial bacteria used.

How to Control Plant Pathogens with Living Soils

A USDA study on strains of Streptomyces, a beneficial bacteria, found that an integrated approach would be the most effective means to overall plant health<5>.

Using multiple beneficial bacteria strains, along with proper water and nutrient availability, and limited soil compaction are the best practices for successful control of soil pathogens<6>.  Just like any other healthy ecosystem, having a diverse array of species present, with minimal disturbance, breeds a robust and resilient living soil that can protect, and provide support for the vegetation present.

GreenEden’s Inoculant Products provide these factors, with a potent, diverse blend of Mycorrhizal Fungi, Beneficial Bacteria, and Plant Biostimulants.

These work in combination to ensure the success of seedlings and transplants for your grow.  Living soils grow better plants.  This is done by encouraging a healthy rhizosphere populated by beneficial biology that out-compete, overpopulate, and attack plant pathogens.  It is this diversity and strength of living soils that protect against a wide range of soil borne pathogens, with the added benefits of enzyme and growth hormone production, organic matter breakdown, nutrient and water use efficiency, and more.  Natural, organic inputs, with no chemicals or synthetics.

A small dusting contacting the roots is all that is needed to unlock the benefits of rapid root establishment, professional grade plant performance, and protection against soil borne pathogens.

Growing in living soils, and following a set of simple, and repeatable best practices will ensure that you can keep your plants healthy and get the results that you want.

Think of it like an insurance policy for your plants.

p.s.  If you like this post, please like and share on Instagram and Facebook.  Spread the word on how to Boost Your Grow the Natural Way. 

references:

<1>Gulhane, V.G., et. al., 2005.  Biological control of damping off of tomato caused by Pythium aphanidermatum (Eds.) Fitz.  Journal of Soils and Crops Vol. 15 No. 1 pp. 118-121 ref. 9

<2>Fayadh, M.A., Aledani, A.A., 2011.  Effect of some microelements and biological control agents in control of tomato seedling damping-off caused by Rhizoctonia soloni Kuhn.  Basra J.Agric.Sci., 24 (1)

<3>Rajendraprasad, M., et. al., 2017.  Biological control of tomato damping off caused by Sclerotium rolfsii.  Journal of Entomology and Zoology Studies; 5(5): 113-119

<4>Sotoyama, K., et. al.  2015.  Biological control of Fusarium wilt by Bacillus amyloliquefaciens IUMC7 isolated from mushroom compost.  Journal of General Plant Pathology; March 2016, Vol. 82, Issue 2, pp. 105-109

<5>Xiao, K., et. al.  2001.  Biological Control of Phytophthora Root Rots on Alfalfa and Soybean with Streptomyces. Biological Control 23, 285–295 (2002)

<6>Larkin, R. P., and Fravel, D. R. 1998. Efficacy of various fungal and bacterial biocontrol organisms for control of Fusarium wilt of tomato. Plant Dis. 82:1022-1028.