somewhat contrary to the Article, Esca is a huge problem in Germany. The disease has been known in Europe since Roman times, so is no newcomer. It is believed to be spread through pruning –it is correctly or incorrectly thought to be transmitted to the next healthy vine from contact with infected shears. It also appears that the recent milder winters may also play a part in the outbreak of Esca. The disease actually starts in the canes, but is drawn into the trunk through the vascular systems in the vine as the sap retreats in fall and winter. If you catch it early enough, it is possible to amputate the diseased wood (even quite far down the trunk towards the scion) and encourage a sucker to be re-trained as the new trunk. For this reason, it is important to mark the infected vines and allow suckers to develop as it can be difficult to identify in winter. The symptoms are as were reported, and also include a tiger-stripe pattern on the leaves. The rule of thumb is to clear and replant a vineyard if your Esca count is around 20%, but many producers with old-vines will end up pulling out only the infected vines (after they’ve been shown to be too far gone to re-train a sucker). This requires vastly more labor, but is necessary to keep the average vine-age in a vineyard at the maximum.
Oddly, and so far unexplainably, Riesling seems to be more sensitive to Esca than other varieties, though nothing that we grow is immune. I will be replanting about 800 vines next spring that were lost to Esca in 2012 (Riesling and Pinot Blanc.) It is a real PITA since there are really no answers.
Esca has also been a problem in CA and the Pac NW for decades, though is on the rise there too.
Wein schenkt Freude