The Performance of Vigorous Nematode Resistant Rootstocks in Field Trials in the San Joaquin Valley

¹ Department of Viticulture and Enology University of California, Davis

Three experimental rootstock plantings in the San Joaquin Valley are described. Yield data and measurements of vigor are presented, as well as a description of cultural practices which are best suited for the proper management of the grafted vines.

The use of the vigorous nematode-resistant rootstocks is sound vineyard practice in plantings on sandy, low-fertility, nematode-infested soils of the inferior valleys. Under commercial vineyard conditions, grafted vines require practices not commonly used in own-rooted plantings. Data show that a careful program of cultural practices utilizes the vigor of the grafted vines to produce large, profitable crops of fair quality. Careful pruning, fertilization, and irrigation will all help achieve this end.