An article by Arthur O. Tucker, PhD, and Rexford H. Talbert appears in the 100th issue of the peer-reviewed journal, HerbalGram (American Botanical Council [1]) published in 2013, which identified the manuscript as being of 16th century New World origin.

A link can be found here [2], with the pdf here [3] (checked April 2017). There are mentions on various other websites.

Other analysis states that the Voynich Manuscript is of the early 15th century and of Italian origin.