Issue link: http://read.dmtmag.com/i/51841
VINEYARD Grapevines are generally very vigorous and "weedy" – they like to and do grow fast. If you consider most plants that you might buy at Home Depot of equivalent size and vigor – fruit trees, for example – they would be in at least a 1-gallon pot and probably in a 5-gallon pot. Fruit trees are usually bare root, with roots up to 2 feet long. ROOTSTOCK SELECTION Rootstock selection should be one of the first decisions in the vineyard development planning cycle. Rootstock varieties are single species or hybrids of the Vitis gen- era selected from wild vines grow- ing the length and breadth of North America, frequently in hot and arid southern states. Rootstocks are selected for vigor, effect on matu- ration and scion ripening, tolerance to drought, wet soils and salinity, resistance to soil pests (in particu- lar, nematodes), and tolerance of other factors such as elemental extremes. Site and soil studies should be undertaken in advance of land purchase with usually one back- hoe pit dug per acre – fewer or more depending on site variability. Knowledge of the surface and sub- surface chemistry and physics of the site along with location, eleva- Contact tion and anticipated climate, permit the selection of an appropriate root- stock. Rootstock selection should be done right the first time, and it is not a business for the inexpe- rienced. Analysis of the soil will permit calculation of total available water-holding capacity, a compo- nent critical for rootstock selection. This, in conjunction with soil depth and the presence of any undersur- face barriers to root growth (hard pan), will help determine which rootstock best suits the site condi- tions. For example: Vigor and dry farming: 110R and 1103P are vigorous rootstocks that are frequently considered for dry- farming programs. Both have deep root systems and are easy to propa- gate and field graft. St. George is also good for dry farming in deep soils. Recent observations suggest that 110R may exhibit incompat- ibility in some circumstances, high- lighting the importance of pathogen testing of plant materials. Nematode tolerance: VR 039-16, a Vitis vinifera x rotundifolia hybrid, is the only choice for soils con- taminated with Xiphenema index, the vector of fanleaf virus. These pathogens are particularly prevalent in the Rutherford region of Napa CALIFORNIA GRAPEVINE NURSERIES Nursery E-mail Casa Cristal Cal Western Duarte Guillaume Herrick Grapevines Martinez Orchards Mercier NovaVine Sunridge Vintage Nurseries WWW.VWM-ONLINE.COM Andrew Zaninovich Anthony Silveira John Duarte Eckhard Kaeskamp Bob Herrick Ernie Bowman Sebastian Traviesa Sam Caselli Andrew Jones Dustin Hooper info@casacristal.com calwestern@msn.com john@duartenursery.com eckhard@guillaumenurseries.com herrickgrapevines@hotmail.com ernie@martinezorchards.com Valley, where VR 039-16 is used almost exclusively in contaminated soils. 420A, 1103P, 101-14 MG and 1616C all have moderate to high resistance to root knot nematode. Heavy wet clay soils: 1616C is a good choice for high-quality fruit and wine production in heavy clay soils too cold and wet for 420A. Partly because of its respectable nematode resistance, interest in 1616C has grown dramatically in recent seasons from California growers producing some of the very best wines. This rootstock is moder- ately vigorous, but like 420A, seems to be particularly prone to crown gall development. For this reason, bench grafting of 420A and 1616C is preferred over field grafting. Phylloxera resistance: The root- stocks currently farmed in the United States were selected for their resistance to phylloxera. By and large this resistance is hold- ing up well, although there is some evidence to suggest that under particularly difficult field condi- tions 101-14 MG – when stressed by nematodes and phylloxera – can show some decline. Professor Andy Walker of UC Davis recently reported that on challenging sites, both 101-14 MG and 1103P have been colonized by the aphid, but Specialty Wine grapes, table grapes, raisin grapes Wine grapes, table grapes, raisin grapes Potted vines, 42-inch-long vines, wine and table grapes Proprietary French selections ENTAV (French) selections Wine grapes and dormant rootings sebastian.traviesa@mercier-groupe.com ENTAV (French) selections scaselli@novavine.com grapevinejones@gmail.com dustin@vintagenurseries.com VCR (Italian), TCVS (French) selections ENTAV (French) selections; wine, table and raisin grapes Wine, table and raisin varieties. California Table Grape Commission JAN - FEB 2012 VINEYARD & WINERY MANAGEMENT 65