Greetings,
Third year in a row specific vines get hit hard with downy mildew. Same vines, no difference in the surroundings, ground is clean, the downy seems to radiate from one area. Other vines of the same variety and more susceptible varieties remain clean. I use copper sparingly and do two dormant spray. I keep up with spraying and rotating different fungicides. Anyone have experience with eradicating what appears to be a locked in systemic downy mildew problem?
Third year in a row specific vines get hit hard with downy mildew. Same vines, no difference in the surroundings, ground is clean, the downy seems to radiate from one area. Other vines of the same variety and more susceptible varieties remain clean. I use copper sparingly and do two dormant spray. I keep up with spraying and rotating different fungicides. Anyone have experience with eradicating what appears to be a locked in systemic downy mildew problem?