Issue link: https://read.dmtmag.com/i/620640
6 6 V I N E YA R D & W I N E RY M A N A G E M E N T | J a n - F e b 2 016 w w w. v w m m e d i a . c o m MITIGATION irst frosts and cold mid-winters have long been romanticized in popular culture, but for a grapegrower, unexpected turns in temperatures can cause significant cold injury. The past two years, for exam- p l e , b r o u g h t s u b - z e r o w i n t e r temperatures to North American g r a p e g r o w i n g a r e a s , i n c l u d i n g -13°F in the Finger Lakes and -29°F around Lake Erie. In Michigan, growers experienced two very difficult winters, with up to 50% crop losses as well as vine losses, according to Paolo Sabbatini, asso- ciate professor in the Department of Horticulture at Michigan State University. + Cold injury can occur any- where in North America, potentially causing crop and vine losses. + Bud injury is typically the easiest damage to assess. + Trunk damage can result in growth problems and disease, and it can com- promise the vine. + "Spare parts" use is an effective means of mitigating cold damage, experts say. + The best cold damage prevention is basic, good viticulture practices. AT A GLANCE "There are really a series of problems" that can occur when temperatures become unexpect- edly cold, said Timothy E. Martin- son, senior extension associate at the New York State Agricultural Experiment Station, Cornell Univer- sity. Those problems can include bud damage, trunk damage and, in cases of extreme or prolonged cold, the death of the vine. In addition to the damage done by winter temperatures that fall below the minimum hardiness level for a given grape variety, problems can occur when late spring frosts damage breaking buds, or when early cold weather catches growers unprepared. COLD INJURY PREVENTION Simple measures help growers avoid or minimize vineyard damage BY LINDA DAILEY PAULSON AND A full week after a freeze in late May 2015, Riesling vines in this Michigan vineyard have no visible green leaves. Photo: Michigan State University