Issue link: http://read.dmtmag.com/i/386317
www.goodfruit.com GOOD FRUIT GROWER OCTOBER 2014 15 STE. MICHELLE hosts rootstock trial C hateau Ste. Michelle Wine Estates will compare the nematode resistance of four rootstocks in a rootstock trial to be planted at its Canoe Ridge Estates near Paterson, Washington. A small trial to compare the effi ciency and survival of bench-grafted and fi eld-grafted vines will also be included. Washington State University recently completed a comprehensive rootstock trial, but this is one of the fi rst full-scale rootstock studies to take place in a commercial vineyard in the state. WSU's Dr. Michelle Moyer designed the new trial, which she will supervise along with U.S. Department of Agriculture's Dr. Inga Zasada. Dr. Markus Keller, WSU viticulturist, will help with some of the data collection. All four rootstocks will be bench-grafted to Chardonnay clone 15, which will be the scion of all the vines in the trial, according to Bill Riley, senior viticulturist for Ste. Michelle. Chardonnay clone 15 on its own roots will be planted as the control, along with a self-graft of Chardonnay clone 15 rootstock to Chardonnay clone 15 scion as a second control. This will provide a control for evaluation of any effects of grafting. The rootstocks included in the trial are: 101-14 Mgt (Millardet et de Grasset), Teleki 5C, 1103 P (Paulsen), Harmony, and Chardonnay clone 15. The six treatments will be replicated four times in a randomized complete-block experimental design. Each treatment will consist of one row of 105 vines, with the six rows contiguous. All total, the trial will involve 24 rows of vines. Riley says another small trial will compare different propagation techniques of bench grafts and fi eld grafts. Washington grape growers have little experience with bench or fi eld grafts because most vines are planted on own roots. "The propagation trial will consist of two rows of 105 vines each, with half of the vines in each row either bench-grafted or grafted in the fi eld," he said. "We're doing this to see how the fi eld graft compares to bench grafts." Rootstock for the grafting comparison will be 101-14 Mgt and Chardonnay clone 15 as the scion. Both trials will be planted in 2015. —M. Hansen Grapes 2. Cast a wide net in your search. (Sometimes a clone not favored in one region will do well in another. For example, Ste. Michelle has found that a Cabernet Sauvignon clone from Germany, not particularly favored in California, is doing well in Washington.) 3. Draw on the experiences of fellow growers. 4. Expect change through the years in the performance of clones. 5. Continue to evaluate clonal differences. Ste. Michelle's clonal trial involves multiple sites throughout the state. Clonal grapes are annually made into wines and the company holds blind tastings several times throughout the year to evaluate wine differences and preferences. Identifying which clone is preferable for wine qualities like fl avors and aromas is diffi cult, he said, because the differences are subtle and often jump around from year to year. Blind tastings are key to shaking out winemaker preferences. "The best use for clones is to consider them as 'spices' that winemakers can use to add diversity and complexity to wine," he said. "An incorrect choice on the clone side is a learning experience; an incorrect choice with vine cleanliness can be pretty tragic." Rootstocks Grower attitudes on rootstocks are changing. Once considered taboo— winter- damaged vines on rootstocks cannot be retrained from the ground as can vines of own roots—rootstocks are now being considered as replanting options in areas where nem- atodes are a problem. Research recently published by Washington State University identifi ed fi ve root- stocks resistant to nematodes and phylloxera that performed well under eastern Wash- ington conditions. For the fi rst time, Ste. Michelle will be testing nematode-resistant rootstocks in a few acres during replanting efforts at Canoe Ridge Vineyard and Columbia Crest Vineyards, both in Horse Heaven Hills. (See Ste. Michelle hosts rootstock trial.) Both locations have sandy soil, a soil texture that is prone to nematode infestations. "It's time to try nematode-tolerant rootstocks in the state," Corliss said. "We're going to take advantage of our replanting efforts and try some rootstocks." WSU and U.S. Department of Agriculture researchers will supervise the trial and help collect data. The rootstock trial will also study different propagation and fi eld grafting techniques. • PHOTOS COURTESY OF CANOE RIDGE ESTATES