Issue link: https://read.dmtmag.com/i/635697
www.goodfruit.com Good Fruit Grower FEBRUARY 15, 2016 15 Eutypa lata. Eight other fungi caused the remaining cankers. She found symptoms in all her sample vineyards, with infection rates ranging from 3 percent to 33 percent, and the rates correlated with the age of the vines. At a 230-acre vineyard in the Yakima Valley with vines more than 40 years old, she found a disease rate of 33 percent. At a 2,000-acre vineyard in the Horse Heaven Hills with vines 30 years and older, she found a disease rate of 18 percent. At a 170-acre vineyard in the Horse Heaven Hills with vines 16 and 17 years old, she found a 3 percent disease rate. Prevention potential The only means of eradicating an infection from a grapevine is by cutting out the infected wood, but healthy-looking wood can also harbor infection. In California, researchers have identified the two most effective preventative practices: —Delaying pruning to a time when the risk of infection is lower (rain induces spore release, and cold weather can lengthen the time a vine needs to heal from pruning or another wound). —Double pruning, which requires two passes through the vineyard. The first pass, after harvest, prunes canes to 10 to 12 inches above the previous year's spurs. The second pass, in mid-March or later, prunes canes to the desired spur length. Vine surgery unveiled "T he idea is to cut away wherever you think there might be infection. You can see the dis- colored wood. It's visible. Work your way down the canopy, cutting away the rotted, darkened wood. As you go farther down the trunk, closer to the base, the wood ends up looking healthier and healthier. Just don't go all the way down to the rootstock. "It's something that can be affordable, rather than replanting a whole block, which just costs tens of thousands of dollars. If you want your vineyard to last 20 to 30 years, and you end up having to replant in year 20 because your yields are so low, it's just so expensive. It would be so much better, maybe in year 15, to start retraining so you can keep those vines going longer." —Dr. Kendra Baumgartner PHOTO COURTESY OF KENDRA BAUMGARTNER The most common symptom of the dieback-type trunk diseases (Botryosphaeria dieback, Eutypa dieback, and Phomopsis dieback) is a dead spur. It can take several months to several years for an infected spur to die, depending on the aggressiveness of the trunk pathogen. W W W.W I L L A M E T T E N U R S E R I E S .C O M ( 503 ) 263-6405 TOLL FREE: ( 800 ) 852-2018 Prunus avium/P. mahaleb M.106/M.7/M.26/B.118 Gisela Series Kyrmsk Series OHxF Series Geneva® Series M.9 Clones CANBY, OREGON are planted with the most popular seedling, semi-dwarf and dwarf varieties: Like our rootstock, our service will grow on you. All Fruit tree rootstock is Oregon certified virus-free. We also grow a great selection of rootstock varieties for apple, peach pear and plum including: MALUS ANTONOVKA MALUS DOMESTICA PRUNUS PERSICA 'LOVELL' PRUNUS CERASIFERA PRUNUS MARIANA PRUNUS MYROBALAN PYRUS CALLERYANA PYRUS COMMUNIS PYRUS USSERIENSIS PROVENCE QUINCE APPLE PEACH PLUM PEAR Pest-Effective: • Season-long mating disruption • More starting active ingredient • 20% more pheromone released during the growing season Cost-Effective: • Season-long control with one application • Hand-application costs cut in half; no labor-intensive twist-ons • Minimal regulation • No harm to beneficial insects • No girdling losses Consistent, Season-Long Codling Moth Control NoMate ® CM Spiral is superior by design and performance for codling moth mating disruption in apple and pear orchards. No competing product goes on more easily, works harder, or gets better results. NoMate® CM Spiral is designed, manufactured, and supported in the United States by Scentry Biologicals, Inc., maker of the first pheromone-based product approved by the U.S. EPA. 610 Central Avenue Billings, MT 59102 (406) 248-5856 1-800-735-5323 www.scentry.com Slip-on NoMate® CM spirals consistently release volatilizing solid-matrix pheromone through flexible PVC dispensers. Female moth scent plumes are overwhelmed, thwarting male moth mating efforts. For more information, call 1-800-735-5323 or visit www.scentry.com.