Mummy berry cups have been found by growers in their fields in West Rockport and Liberty. Numerous cups and pinheads were seen in plots this weekend by these growers. The growers also report the plants in their fields were not open enough to be susceptible with the rain this weekend.
Plants will have enough susceptible tissue to become infected when more than 40% of their flower buds are at the F2 stage of development (the crown stage). Before this point in development the plant tissue is protected by the bud scales from fungal infection. Fungicides will also not be able to penetrate the bud scales very well. To check your plants, look at a random sample of at least 20 stems across your field (from different clones) and count the number the stems with F2 buds.
If you have a mummy berry plot, I would like to hear from you when you see cups starting to appear and when they end.
If you have any questions please contact Seanna Annis. Telephone: 1- 800-897-0757 (Maine only) or 207-581-2621, Email: firstname.lastname@example.org.