
Wood vinegar, also known as pyroligneous acid, contains over 200 organic compounds, decomposed and extracted from biomass using a moderate amount of heat in the absence of oxygen. Plants have evolved to produce these compounds over the last 470 million years. They resist attacks by insects, fungi, and bacteria, and keep themselves healthy and thriving by selectively and synergistically utilizing these organic compounds.
Since plants have invested hundreds of millions of years of "evolutionary research" into the development of the mix of organic compounds that are wood vinegar, it should not be a surprise to discover that it can be very effective. When it works for a particular purpose, it tends to work very well. It should also not be a surprise to learn that parasites, bacteria, and fungi find it difficult to mutate around the synergistic effects of wood vinegar. If it was easy, as is often the case with single chemical pesticides and pharmaceuticals, they would have done so already.
Unlike chemical pesticides, properly produced wood vinegar at recommended dosages is non-toxic to livestock, pets, and people. It stimulates the growth of beneficial soil microbes and does not cause environmental side effects. The organic compounds in wood vinegar are components of the foods we eat in concentrated form, and they quickly and easily decompose in the soil, just like any other biogenic material.
A highly effective pesticide and fungicide that nurtures soil microbial life stimulates plant growth and is optimally biodegradable sounds highly unlikely, but that's what 470 million years of evolution has produced. Perhaps we should rely on wood vinegar's natural, evolved wisdom whenever possible, rather than on chemicals produced in a laboratory from relatively few, isolated experiments that have proved to have numerous, negative side effects.