Grape Variety: UCD GRN-4

Variety Name	UCD GRN-4
Common Synonyms	9365-85
All Synonyms	9365-85, Walker 9365-85
Countries of Origin	USA
Species	It includes Vitis rufotomentosa, Vitis champinii, c9038 (Vitis monticola)
Breeder	Dr. Andy Walker
Institution	University of California, Davis
Year Released	2008
Status of Ownership	Proprietary to UC Regents
Pedigree	Several grape species, including Vitis rufotomentosa, Vitis champinii, c9038 (a wild collection from Texas that appears to contain Vitis monticola), Vitis riparia
Uses	Rootstock
Comments	UCD GRN-3™ and UCD GRN-4™ are siblings. UCD GRN-4™ has good resistance to root-knot and dagger nematodes and also resists citrus and lesion nematodes - it is susceptible to ring nematodes (sibling UCD GRN-3™ has moderate resistance to ring nematodes). Cuttings root well and rooting angles are intermediate in length. This selection resembles V. riparia more than its sibling does. UCD GRN-4™ has slightly lower nematode resistance than UCD GRN-3™ but is a more vigorous mother vine.

UCD GRN-4 Selections

	UCD GRN-4 [01] (proprietary)
Registration Status	Registered
Source	Department of Viticulture & Enology, University of California, Davis
Proprietary	Proprietary- cannot be distributed without written permission from owner.
Comments	This selection was developed by University of California, Davis, Viticulture Professor Andy Walker and was released in 2008. It was formerly known as 9365-85 (Walker 9365-85). For a complete explanation of the selections in this series, see the article entitled 'Walker Nematode-resistant Rootstock Releases' in the October 2008 FPS Grape Program Newsletter at http://fps.ucdavis.edu/, in the Publications section. The original material underwent microshoot tip tissue culture therapy in 2010 in order to qualify for the Russell Ranch Foundation Vineyard, where it was planted in 2012 as UCD GRN-4™ FPS 01.1.