We seem to be in a Goldilocks sweet spot in regards to moisture- just enough for the vines, not too wet to get work done. That can let some folks get complacent, but as vines are entering the immediate prebloom period, we are at peak disease pressure with all of the major diseases active to one degree or another. Every vineyard should be covered with the full suite of disease management products this week. That means mancozeb or captan plus a DMI, SDHI, or strobilurin (group 3, 7, or 11, respectively) material for non-organic vineyards; and sulfur plus copper (watch for incompatibilities on certain varieties, page 9 here) on organic vineyards. This would also be a good time to add biologicals, since we’re at ‘all hands on deck’ right now. Some materials, like Lifegard and Howler, are systemic acquired resistance promoters and need to go on a few days prior to infection. Others, like Serenade and Double Nickel, are biological extracts but can be mixed with other materials. Either way, these applications should be made a before infection, so spraying in the next day or two is a good idea.
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