Trichoderma Fungus General Description

The fungus Trichoderma is a filamentous, free-living fungi that are common in most soils and root ecosystems worldwide. Trichoderma have been found in prairies, forests, salt marshes, desert sands, lake water, dead plant material, seeds and air. They are also found in living roots of virtually any plant (1). Biocontrolfungi of Trichoderma have developed an astonishing ability to interact, both parasitically and symbiotically, in a variety of substrates, plants and with other microbes (2,3). Today Trichodermas is used more extensively in agriculture than any other single microbe. There are many effective Trichoderma species. So far, there are only 7 important Trichoderma species used commercially but more are being added to the list every year.

  1. Trichoderma asperellum
  2. Trichoderma harzianum
  3. Trichoderma hamatum
  4. Trichoderma koningii
  5. Trichoderma longibrachiatum
  6. Trichoderma pseudokoningii
  7. Trichoderma viride

Trichoderma Fungus Mode of Action

Trichoderma’s first claim to fame a few years ago was being a microbial predator, highly antagonistic of other fungus. They are specialists at killing other fungi with a  toxin. They then consume their prey by dissolving them with an exudent of lytic enzymes. This predatory behavior has led to their use to control other fungi plant disease. Interestingly enough it does not seam to have a negative influences over mycorrhizal fungi. Mycorrhyzal is another very beneficial fungus in the rhysophere. Cornell University’s recent research is quite interesting. It has found that Trichoderma’s disease control function is only the tip of the iceberg. In actuality, Trichoderma has a quite well defined symbiotic relationship with plant roots. They not only inhibit other fungus but supplying nitrogen to plant roots much like mycorrhizal fungus

Trichoderma establish robust and long-lasting colonizations of root surfaces and penetrate into the epidermis and a few cells below this level. It then release different compounds that induce localized or systemic resistance responses. This explains their lack of pathogenicity to plants. These root–microorganism associations cause substantial changes to the plant proteome and metabolism. A recent discovery in several labs is that some strains induce plants to “turn on” their native defense mechanisms gives the impression that Thrichoderma will also control pathogens other than fungi. Plants are protected from numerous classes of plant pathogen by responses that are similar to systemic acquired resistance and rhizobacteria-induced systemic resistance.

Trichoderma Fungus Mode of Application

Trichoderma is normally supplied as a culture developed on softened rice. Place a kilo of this inoculated rice in a pale of de-chlorinated water along with 5ml of any available surface tension breaker. Let it sit for an hour or so as to let the rice soften further. Grind the rice between your hands to liberate the fungus from the rice. Do this grinding for a few minutes until the Trichoderma is practically all washed off of the rice. The rice will be a much lighter shade of blue-green at this point. Strain the liquid in a fine meshed food strainer to take out the larger chunks of rice. This is important only if you are going to be spraying the liquid on the phylosphere of the plants for fungal control, so the spray head doesn’t clog. If it is to be applied as a drench on roots, obviously there is no need for pre-straining.

References

1. Monte, E. 2001. Understanding Trichoderma: Between biotechnology and
microbial ecology. Int. Microbiol. 4:1-4.

3. Harman, G. E., and Kubicek, C. P. 1998. Trichoderma and Gliocladium,
Vol. 2. Enzymes, Biological Control and Commercial Applications.
Taylor & Francis, London.

3. Kubicek, C. P., and Harman, G. E. 1998. Trichoderma and Gliocladium.
Vol. 1. Basic Biology, Taxonomy and Genetics. Taylor & Francis,
London.