5.03.13 Mummy Berry Forecast for May 3

Mature mummy berry cups have been found in most blueberry areas. Some fields have their first batches of mummy berry cups starting to dry up.  New pinheads are also coming along so the season is still on-going.

I expect many fields now have over 40% of susceptible stems and so they have enough plant tissue to be infected.

You need three things for mummy berry infection: the fungal spores, susceptible plant tissue AND suitable weather conditions. Good news is… there have been NO conditions detected for mummy berry infection since last week. The dry conditions have produced no infection periods.  Some fields are experiencing heavy dew overnight, but temperatures are too cool and the dew is lasting for too short a time to cause an infection period.

I expect the earliest we can expect infection periods in most fields are during the rain forecast for late next week. The only conditions to watch out for are long fogs overnight.  Under overnight temperatures averaging about 44º to 45ºF, AND  a fog for greater than nine hours may produce an infection period. I have not yet seen these conditions in the fields we are monitoring with weather stations.

If you have any questions, please email me at sannis@maine.edu or call me on the blueberry hotline (in Maine) 1.800.897.0757.

– Seanna Annis