Plant production with less mortality rate

I am a plant producers for almost 35 years already and I have produced a lot of ornamental seedlings of different kinds. My productions of plants is so fast and has less mortality rate for i used vacuum type of production wherein I placed the seedling bags inside the clear plastic sheet and wait for at least 2 to three months before I open it for harvest. Vacuum type of production has less mortality rate compared to cuttings and grafting because inside the clear plastic bag it provides high humidity rate and this is the reason why plant inside the bags easily hydrate and have their primary roots.