Hunter Valley wine rot), "Greeneria uvicola" (bitter rot) and other fungi from the genera of "Aspergillus, Penicillium" and "Alternaria". Susceptibility of certain wine grape varieties were found to increase as the grapes reached higher Brix sugar levels. Further research in the 2000s, showed that some of the open canopy techniques used to prevent "Botrytis" grey rot may actually promote the development of some of these other types of rot. Ripe rot, in particular, seemed to thrive at the higher ultraviolet B (280–320 nm) light exposure that open canopies allow. To compound the potential problem for Hunter Valley wine growers is that, as of
Wine Grapes franc may have originated in Basque country of Spain. Additionally the origins of the assumed to be French varieties of Mourvèdre, Grenache and Carignan are shown to likely be Spanish instead. Another detail revealed by DNA testing and reported in "Wine Grapes" is that several northern Italian white wine grape varieties including Favorita, Pigato and Vermentino are genetically the same grape vine which is known under the synonym of "Rolle" in France but has no genetic relationship to the Rollo grape of Liguria. A number of grape varieties are illustrated by reproductions of colour plates from "Ampélographie. Traité général de