Title: "INFECTION AND SPREAD OF Peronospora sparsa IN Rosa sp. (Berk.)- A MICROSCOPIC AND THERMOGRAPHIC APPROACH"

http://hss.ulb.uni-bonn.de/2014/3473/3473.pdf

H.Kuska comment: In a quick read through, I did not see much in this thesis that would be useful to the general rose growing public. I expect that its main use would be as background material for those who are interested in writing an article about downy mildew for rose growers.

Here is a link that might be useful: link to complete thesis