I don’t mean to scare you guys, but conditions are looking worse rather than better. The CougarBlight model on Orchard Radar now predicts the risk of fire blight infection is Exceptional for Sunday and Tuesday in Providence County, and Extreme for Monday and Wednesday . Exceptional is a worse rating than Extreme. Any apple trees that are in bloom on Sunday are at risk of fire blight infection. I think this is also true of any apple and pear trees in bloom anywhere in the state.
Sunday – Exceptional
Monday – Extreme
Tuesday – Exceptional
Wednesday – Extreme
Thursday – High
You can see this at http://ag-radar.umext.maine.edu/RImodel/RI-Greenville-FireblightWA.htm
It looks like at least 2 strep applications will be needed to protect trees through bloom. Strep applications will protect blossoms for 24 hours and reach back 24 hours after an infection starts – but just like apple scab – it is risky to rely on spraying after an infection occurs. I think a good plan is to apply strep Saturday evening or Sunday morning and plan to spray strep again on Tuesday.
I hear it is probably all right to apply strep along with other fungicides, as long as the fungicide isn’t captan or Fontelis.
Include Regulaid or LI 700 with the first strep application.
I’m available to answer your calls and emails until 3:00 Sunday afternoon. And then again on Monday, like normal.