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WineEast reductions in fine root growth and colonization by arbuscular mycorrhizal fungi (AMF) occurring as early as the second year. Reductions in both fine-root production and AMF colonization due to ring nematode were greater during subsequent years in the susceptible vines. The frequency of fine roots containing vesicles of AMF was reduced in all five rootstocks that supported a population increase of ring nematode (only 420A was unaffected.) Ring nematode did not alter above-ground vine performance until the third or fourth growing season, when shoot lengths and pruning weights were reduced in the three susceptible vines. By year four, however, ring nematode reduced fruit yield across all rootstock treatments. R.P. Schreiner, I.A. Zasada and J.N. Pinkerton. Amer. J. Enol. Vitic. published ahead of print Feb. 14, 2012, doi: 10.5344/ajev.2012.11104. Contact the senior author through the Department of Horticulture at Oregon State University: (541) 738-4084, (541) 738-4087 or schreinr@mail.oregonstate.edu. Rootstock LN33 presents necrotic symp- toms when inoculated with isolate CB 120. Effects of viruses associated with rugose wood complex on rootstocks H&W_Dec10.qxp 10/12/10 10:59 AM Page 1 Four rootstocks (Vitis rupestris St. George, Kober 5BB, LN33 and Freedom) were graft-inoculated with viruses associated with the rugose wood complex (RW) to study their growth response and symptom expression. The virus sources used in this study were isolates LR127, CB111, CB105 and PA94-142 (grapevine virus A, or GVA); CB120 (grapevine virus B, or GVB); LV92-07 and a field selection of Chardonnay (grapevine virus D, or GVD), and a field selection of Cabernet Sauvignon (grapevine rupestris stem pitting-associated virus, or GRSPaV.) Each rootstock plant was graft-inoculated with one, two or three virus sources using bud chips from virus-infected grapevines. After two years, plant diameter was measured, bark was removed and the woody cylinders were observed for the presence of RW symptoms and rated based on symptom severity. The greatest reduction in trunk diameter was in plants inoculated with the virus source combination of GVB+GVD+GRSPaV, regardless of the rootstock. Furthermore, GVB+GVD, GVA+GVB+GVD and GVB+GVD+GRSPaV had the highest effect on LN33 growth, and GVA+GVB+GRSPaV, GVB+GVD+GRSPaV and GVA+GVB had the greatest effects on 5BB. In general, GVB source material had more adverse effects on growth in multiple infections, particularly in triple combinations. When You Require A Consistent Supply GRAPE SOURCING: WINERY SUPPLY: TRANSPORTATION: By variety, appellation or specification All equipment and supplies for all phases of winemaking Logistical network operating daily from coast to coast Your Source For Quality Products including: fresh grapes, juice and bulk wine 101 Reserve Road * Hartford, CT 06114 * 877-812-1137 * Sales@JuiceGrape.com WINES & VINES AUGUST 2012 63 ADIB ROWHANI