04.25.17 Mummy Berry Infection period in Midcoast Region, April 25 to 26

Knox, Lincoln and Hancock Counties

All grower reports early this week were that there were mummy berry cups in fields in these regions and the plants were far enough along or close to it for infection. The steady wet weather produced an infection event recorded at all of our weather stations in those regions (Waldoboro, West Rockport, Appleton and Searsport). The infection period started on Tuesday, April 25 around 7:00 to 10:00 p.m. and continued through to this morning, Thursday, April 27. I expect we will have another infection event with the wet weather predicted to start on Monday.

Hancock and Washington Counties

I have reports of mummy berry pinheads and cups from Ellsworth, Eastbrook and through out the barrens as of early this week. The consensus among most growers were the plants were not yet ready in most fields (not at 40% F2 flower buds). These are the percentage of flower cluster buds at F2 in the fields we have visited on April 25; Sedgwick 27% , Aurora 22%, Eastbrook 25 to 36%, Deblois area very few F2, BBHF in Jonesboro 17% ).    If you have an early field you may have had an infection period over the last two days. I expect we will have the first infection period in many fields with the wet weather predicted to start on Monday.

Using Fungicide Controls

If you have applied fungicides within the last seven to ten days (April 18 on) before Tuesday, April 25 your plants were protected during the infection period over April 25 to April 27.  If you have not applied fungicides, you have until the evening of Friday, April 28, to apply fungicides (propiconazole or fenbuconazole) to kill any infection.

Please see the 2017 fungicide recommendations on the Fact Sheet 219 – Disease Control Guide for Wild Blueberries and the most current Maine Wild Blueberry Pesticide Chart (Fungicides) (PDF). Other fungicides should be applied as protectants and before infection periods occur.