When under attack, plants can signal microbial friends for help

Discussion in 'Organic Lawn Care' started by ICT Bill, Oct 21, 2008.

  1. ICT Bill

    ICT Bill LawnSite Platinum Member
    Messages: 4,115

    Researchers at the University of Delaware have discovered that when the leaf of a plant is under attack by a pathogen, it can send out an S.O.S. to the roots for help, and the roots will respond by secreting an acid that brings beneficial bacteria to the rescue.

    "Plants are a lot smarter than we give them credit for," says Bais from his laboratory at the Delaware Biotechnology Institute.

    "People think that plants, rooted in the ground, are just sitting ducks when it comes to attack by harmful fungi or bacteria, but we've found that plants have ways of seeking external help," he notes.

    In a series of laboratory experiments, the scientists infected the leaves of the small flowering plant Arabidopsis thaliana with a pathogenic bacterium, Pseudomonas syringae. Within a few days, the leaves of the infected plants began yellowing and showing other symptoms of disease.

    However, the infected plants whose roots had been inoculated with the beneficial microbe Bacillus subtilis were perfectly healthy.

    Farmers often add B. subtilis to the soil to boost plant immunity. It forms a protective biofilm around plant roots and also has antimicrobial properties, according to Bais.

    This is not part of the article but bacillus subtillus is also an excellent enzyme producer that attacks many forms of root feeding bad guys
  2. treegal1

    treegal1 LawnSite Gold Member
    Messages: 3,911

    and the punch line, ICT tea has lots of B subtilis in it.........add some npp and its real good at killing.

    an who thanks for the link Bill, maybe next time they will use something use full instead of a simple model plant with a small gene. eh its still proof that it works.

    aren't you supposed to be up early for the GIE show??? what are you doing up on the boards this late??? last minute prep and angst
  3. ICT Bill

    ICT Bill LawnSite Platinum Member
    Messages: 4,115

    Show went great, we really had a good time and met a lot of folks that are on here.

    Yeah I agree about the narrow focus of some of these studies. Soil dynamics are so fluid that they have to focus on one little thing tp prove the initial hypothisis
  4. tadhussey

    tadhussey LawnSite Senior Member
    Messages: 294

    We've found that adding b. subtilis to our compost teas significantly reduced the fungal numbers in our tea vs the control.

    DUSTYCEDAR LawnSite Fanatic
    from PA
    Messages: 5,132

    but it taste great
  6. ICT Bill

    ICT Bill LawnSite Platinum Member
    Messages: 4,115

    Less filling

    Tad, makes sense, those guys (b subtillus) are voracious eaters and can get numbers up so quickly, it is pretty amazing. They will consume resources faster than any fungi for sure. In the soil they are excellent nutrient miners.

    They are also excellent at producing enzymes, there are several triggers that will produce different results

    As a foliar they work great to combat fungal disease
  7. tadhussey

    tadhussey LawnSite Senior Member
    Messages: 294

    I definitely agree that they serve a purpose, I just hope people aren't putting them down indescriminately.
  8. growingdeeprootsorganicly

    growingdeeprootsorganicly LawnSite Senior Member
    Messages: 766


    usefull info about brewing with that strain,
  9. tadhussey

    tadhussey LawnSite Senior Member
    Messages: 294

    With compost tea you want to have the full complement of the soil food web and the highest diversity of microbes in your brew as possible. When you add a high concentration of any particular species, you can pontentially throw this nutrient cycling process out of whack.

    That's why you only want to add particular beneficial species in isolation when you know exactly what they do and you have a specific problem that they address (disease, etc...).

    It's also good to look at what caused your plants to become diseased or stressed in the first place and address that issue for a long term solution.

    These are all concepts I've derived from reading Arden Andersen and Dr. Ingham, and my own personal experiences support these theories as well. With organics we're really going for a symbiosis on a microbial level.
  10. NattyLawn

    NattyLawn LawnSite Bronze Member
    Messages: 1,643

    I think the brewers have added this to tea to see if you can grow it out, as bacillus subtillus or Seranade is not a cheap product. Instead of adding to tea to grow it out, maybe adding foods like molasses would help.

    I definitely agree with Tad though, as a balanced tea is key. A lot of people I talk to are hung up on the bacterial vs. fungal debate.

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