Issue link: http://read.dmtmag.com/i/256927
10 FEBRUARY 15, 2014 GOOD FRUIT GROWER www.goodfruit.com Longstroth said, "If the high or low temperatures drop more than 50 degrees, I worry; 70 degrees, I really worry. This means we had a lot of free water in the plant (or as the growers would say, the sap is up), and it froze real fast and I think damage is likely." "This is the second coldest blast in my 20 years here in Michigan. In 1994, we got to minus 24 to minus 28 degrees F in February. It was so cold the brine was freezing in the pickle vats. We saw many young trees killed outright. Wine grapes killed to the snowline. Tart cherries that were defoliated early died and did not leaf out." He said there were no peaches, and the lower trunks above the snow, where the air is coldest and the tem- perature differential is the greatest, were damaged. Older peaches and plums began to lose leaves during the first dry spell the following season and declined for several years after. Many juice grapes leafed out normally and then collapsed during the summer. "We had dead flower buds in all crops including apples, but other than peaches, wine grapes, and blueberries, the state crops were normal," he recalled. Crassweller noted that wine grape growers will have their vineyards tested by the cold weather. "We've been pushing the envelope on some varieties," he said. Some growers who have planted tender vinifera varieties realize they are at the margin, so they cover their graft unions in the fall to protect at least the base of the scion variety. Still, if grapes are killed back to the rootstock, it will take two to three years to reestablish the vine, and the vineyard will never recover its uniformity, he said. In western New York State, extension educator Deb Breth said tem- peratures had not gotten as cold along Lake Ontario as further south. The polar vortex swept cold air south on the west side of the Great Lakes, and then turned it east along the Ohio River Valley. In southwest Michigan, which is normally protected by Lake Michi- gan, the cold air was actually coming in from the south and east and not crossing the big lake. It was colder in southwest Michigan than it was in northern fruit areas along the lake. Chris Doll, a long-time industry observer in Illinois who retired from the University of Illinois extension program, said in an e-mail, "It is known that resistance and acclimation are two factors that affect freez- ing injury. To me, the classic resistance is that of lambrusca grapes, when compared with vinifera and some of its hybrids. For that reason, I have concerns about the Midwest grape and wine industry that has not seen the damaging minimum temperatures in recent years. "And, for all of the new Prunus interspecies and varieties that have been touted as cold hardy, this might be the test, and I hope that my pessimism is for naught." The frigid weather may have chilled some people's thoughts about global warming. Fear not. The polar vortex, which slid south across North America from the Arctic, also slid north in Europe and Asia on the other side of the world. The high temperature in Sparta, Michigan, at 4 p.m. on January 7 was 7˚F, while in Moscow, Russia, it was 34˚F at the same time (1 a.m. there). That means the Michigan high of the day was 27 degrees colder than the Russian low. "I hope that this is just another of the worrisome cold spells that grow- ers must go through, and that the remainder of the 2013-2014 winter is less stressful," Doll said, expressing the consensus. But after the very cold spell the first week of the year, Michigan temperatures rose to above freezing on January 10 and were expected to fall again the following week. "A roller coaster, that's the concern," Crassweller said. • SYSTEMIC BACTERICIDE/FUNGICIDE BROAD SPECTRUM BACTERICIDE/FUNGICIDE MAXIMUM CONTROL AT YOUR FINGERTIPS. MIN MAX CONTROL Increase your control program with BioSafe Systems. OxiDate 2.0 is a foliar spray proven to kill Powdery Mildew, Late Blight, Bacterical Speck & Spot, and Botrytis on contact while OxiPhos eliminates pathogens like Downy Mildew, Pythium, and Phytophthora with its powerful combination of phosphorus acid and activated peroxide. Unique bactericide and fungicides for complete contact and systemic control like never before. © 2014 1/13 ® LLC Simply Sustainable. Always Effective. 1.888.273.3088 | biosafesystems.com "And, for all of the new Prunus interspecies and varieties that have been touted as cold hardy, this might be the test…" —Chris Doll