Well it appears that May has arrived!
Through most of the region we would have had an infection period from late Monday evening through mid-day on Tuesday. The forecast is calling for significant rain from late Wednesday evening through early Friday morning as well. This will likely be an infection period of concern for many areas.
Many of our sample sites are not quite at threshold yet (40-50% F2) however, we are seeing mature cups in several places. I am confident the naturally occurring mummy berries are ready to release spores in Central NS. Given the weather forecast, if your fields are at the threshold you should consider a treatment.
Propiconazole based products (Topas, Tilt, Jade, Bumper etc.) do have some back-action after an infection has occurred. Some studies have shown up to 72 hours effectiveness after infection, however, the longer away from the infection period you spray the more likely you are to get decreased control. Attempt to spray before an infection period or as close after one as possible.
Below is a list of reported sites:
Glenmore - 24% F2
Wittenburg - 41% F2
Kemptown - 13.4% F2
Corktown - 13% F2
Earltown - 15% F2
Highland Village - 24% F2
Mount Thom - 5% F2
Murray Siding - 38% F2
Masstown - 25% F2
Baseline Rd. - 22% F2
Windham Hill - 24% F2
South hampton - 23% F2
Oxford - 35%+ (1 mature cup, 1 nearly Mature)
Westchester - 15% F2
Amherst - 21% F2 (2 mature cups, 3 nearly mature)
Athol - 32% F2
Pigeon Hill - 25% F2 (early field in this area)
Farmington - 24% F2 (early field in this area)
Glasgow Mt. - 17% F2
Kirk Hill - 31% F2
The eastern end of the province is still early in the development stage.
I want to emphasize that growers should look at individual fields, as there can be a large variation in field development even within a small region. For example, most fields in Mt. Thom are no where near the 40% threshold, but I was in one today that was at 40% F2. Soil type, orientation, field aspect and fertility programs can all impact when fruit buds start to break.