@Mat: I am finding a product called Root Shield with a strain of Trichoderma they call T-22. Are you familiar with this product? If not, what do you use, please?
I experiemtned with rootsheild for a couple years and wasnt impressed.
Two main problems, one is spore count.... its more "filler" than anything else. The spore count is horrible.
Secondly, their product has a 6m shelf life, and no exaggeration... but every time i ordered it, I had to call and complain that the delivered product was already out of date.
caveat emptor of course.
There are many strains of Trich, and some work better on pathogen "A" or pathogen "B"
Also, many do not really understand how to best use it.
Trichoderma sp. are highly antagonistic and parasitic towards pathogens. However, it grows slower than some pathogens. So the key here is to keep a strong, healthy culture present. If a pathogen is already actively attacking the plant... your chances of success are much less likely and may in fact "feed" the pathogen before the Trich population can become active enough to "win the war".
While I have used it successfully as a "cure" its real benefit is as a preventivie. It also forms a symbiotic relationship with the plant that is systemic in nature. This enables to plant to fight off pathogens and increases the plant's nutrient uptake.
Trichoderma is a living organism and alters itself to best match the pathogen it encounters... sort of an "intelligent" bioweapon.
However, it also has its own preditiors and while not common, they do exist... Its also been shown that other bio-products such as some of the B. subtilis strains decrease Trichoderma's effectiveness. Likewise, applying it to a nutrient rich enviroment causes the trich to becomes "fat and lazy"
All the statements I have made above are documented in dozens and dozens of peer reviewed research papers... well except for my personal observations on T-22