Japanese to English Science Agriculture Herbicides/pesticides

Hi all, I've come across this term whilst translating the legal requirements for registering PPP. I'm having a bit of trouble finding an equivalent for this in English - I was going to use active substance/ingredient but that's 活性成分 and it's used elsewhere in the same document. Obviously the direct translation would be agrochemical base but doing agricultural reports in however many languages I've yet to come across that term.

Would formulation be an acceptable translation in this case?

Incidentally I've found this explainer online which explains the difference between the two terms in the Japanese but I'm still at a loss for the best way to render 農薬原体 in English: https://www.jcpa.or.jp/qa/a4_02.html

Many thanks in advance and any websites you could cite would be greatly appreciated!