Revitalization of Vines Weakened by Grape Root Borer: 2007-2008

This block of Pinot Grigio vines has been decimated by Grape Root Borer as reported in earlier years. Indeed, 100 % of dying vines, were found to have been attacked. Without a strong root base, the vines grew poorly. In 2006, we started protecting the vines from Grape Root Borer with Mating Disruption and although few new vines showed signs of decline, many had apparently started on a downward path to death as evidenced by poor foilage and inadequate new shoots in 2007. Some years ago, we had been successful in regenerating Malvasia Bianca vines infected with Esca (or Black Goo disease), by amputating the trunk well below the foliage. The secret was to wait until the sap was flowly vigorously in the Spring and to cut down the trunk until the sap flowed freely from the weakened vine. IF the roots were still active, sap would flow and we reasoned that vine re-growth might occur. It had worked exceedingly well so the same technique was applied in 2007 to the Pinot Grigio. In the picture above, we see 3 strong canes have grown out of the trunk below the amputation site. All but 2 of more than 30 vines re-grew! Most had more than the three canes shown in the example. Canes #1 and #2 were retained. #3 was discarded. The canes were tied down in the traditional double Guyot system we have used in the past to establish mature vines. We expect that the vine will grow well this year but we have no guarantee. Photos will be taken during the 2008 growing season.