Nina wrote:
Downy mildews are very host specific, and the one attacking grapes
wouldn't attack a serissa. Serissa could have a different downy
c
Looking at the symptoms, that sort of chlorosis can be caused by a lot
of things, including nutrient deficiency or a virus. I'd check for
thrips, too.

Nina.
Thank you a Lot for the information Nina I 'll
hand it over to the person
cheers
Tiziano