Never suggested anybody should be perfect. As we are talking about 18th century language it is probable it is impossible to define. What I do know however is that Botanic Gardens, Physics Gardens, famous parks did have armies of gardeners even two hundred years ago and some of them would undoubtedly have been through some sort of training or apprenticeships. I can imagine someone referring to the students at agricultural colleges being described as "future" farmers or "the farmers of the future" but I do not think anyone would refer to them as "budding" farmers. In this sense budding has a very slightly patronising/perjorative note - the description a "budding politician" could describe someone who is a bit too full of him/herself. Very subtle. What is the context of your "angehender Bauer"?