As I see it, there is not what you call a reasonable upper limit of the number of publications an author can produce per year. More important than the quantity of published papers it is their quality that matters. It also matters the Journal where the papers are published. For example, to publish a paper in Science counts more than to publisb 20 or even more papers in low index impact factor Journals.
Of course, one expects more publications from a non-teaching researcher than a teaching lecture. As a reseacher I never published more than, say, 3 good papers.
No limit. It really depends on your ability and also enabling environment favourable for research. Also research funding opportunities, research grants postdoc etc.
No limit. It really depends on your ability and also enabling environment favourable for research. Also research funding opportunities, research grants postdoc etc.