Green mould (Trichoderma harzianum) is a problem that can be controlled using formalin. However, if this method is wrongly used it can even worsen the infection of green mould.
Green mould can be triggered by various causes. Firstly, compost quality is very important. Quality means the structure moisture content and selectivity. Short-structured wet compost can be difficult to make selective because the easily decomposable carbohydrates (EDC) are still present in the compost. These EDC are a nutrient source for green mould.
Another problem is hygiene. If machinery tunnels or the inoculation area are not thoroughly cleaned and compost remains are left behind, disinfection has absolutely no sense. In fact, it will just make matters worse and green mould will have a greater chance of survival. If compost remains are disinfected, the lower layer of the compost is sterilised. Under sterile conditions spores of green mould develop easily. Once again, we can conclude by saying that good general hygiene is more important than chemical agents.
Mark den Ouden, C Point