A wet night and more rains to come

It turned out to be a very nice day for planting at Winchester. We almost finished planting of two vineyards (a total of 1/2 Acre with Chardonnay and Merlot) which will be used for chemical trials and other management-related experiments. We had a drizzle in the early morning, but the expected thunderstorm did not arrive until 8pm or so and it was not as severe as I expected.

On 14th, night time relative humidity was high, but temperature was low (low 40’s), thus it was not a disease night. But last night, we had a series of short rains and temperature stayed in low-60’s with the relative humidity above 90% until now (8am, fog). This >12 hours of wetness accounts for Phomopsis, black rot, powdery mildew, and downy mildew infection events.

We are expecting to see more rains during this weekend, so, please think about potential disease events (in the future or in the past) when you decide for a fungicide application. You can find details of infection events I’m describing here in my notes from past vineyard meetings (you can find them in this blog, or in my AREC webpage).

The growth stage of Chardonnay in our vineyard was 15-20% with 7-8 leaves unfolded (but I did not see significant elongation of the cluster yet, thus between E-L 12 and 15), and that of Cabernet sauvignon was 8-90% with 5-6 leaves unfolded (~7-10-inch, E-L 12).

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