Is "since 50 years ago" acceptable?

What does “pick up on” mean?
I have consulted Longman Dictioanry of Phrasal Verbs and there is no such entry.

Hi sitifan,

It means as much as ‘continue’ or ‘take it from there’.

I’d like to pick up on what you said about bee keeping yesterdy. It opened a completely new dimension for me, and I would like to know where I should persue this peculiar hobby in order to get the best results for producing acacia honey.

(I think I may have meant “pick up on” in a slightly different sense: “notice and comment on”.)