This Winter, much of our time in the vineyard is spent on the task of “Reworking” vines affected by a naturally occurring fungal disease Eutypa Lata. The fungus results in toxins in the wood of the vine that cause the tissue to die, leaving the tell-tale dead arm on the vine with obvious yield and quality implications. The same fungus also affects many fruit trees including Apricot, Peach, Nectarine, Lemon and Olives, as well as many Australian Natives.
The process involves cutting off the affected wood, cutting back as near to the trunk as practical to ensure the diseased sections are removed. Cuts are sealed with a protective paint to prevent fungal spores entering the wounds and re-infecting the treated vines. Canes are laid down to new trellis wire to form a replacement cordon that will hopefully give disease free production for another ten years.
Where the disease extends to the trunk, the trunk is removed about twenty centimetres above ground level and again the cut is protected by paint. Once the growing season commences, shoots called water-shoots will burst from latent buds below the bark surface. The strongest of these shoots will be selected to be trained up to the cordon wire to form a replacement vine trunk and eventually replacement vine cordon arms free of Eutypa.
We are several years into a significant programme of reworking affected vineyards with almost half our vineyards receiving attention to date. The payback for us as Winemakers is the vineyards quickly return to full production, with higher quality fruit with less quality variability. This has an obvious payback in the quality of wine we are able to produce.