UPDATED FORECAST FOR MUMMY BERRY FOR ALL REGIONS Tuesday April 28, 2009

UPDATE: Union, Rockport, Camden area.
There has been an infection period in the Union area. There was long enough rain (more than 8 hours at 48 F) over Monday night and morning for an infection period to have occurred. There are still active mummy berry cups in fields in these areas. Most plants are likely susceptible to the fungus now. To control this disease you can apply fungicide within 72 hours of the START of the rain/fog period in your field. For example if the rain started in your area at 9 pm on Monday you have until 9pm on Thursday of this week to apply fungicide to control the infection.

Belfast, Orland areas
Mummy berry cups are now active in your area. Most plants are close to or are susceptible by now.

NEW: Downeast area, (Deblois, Cherryfield, Jonesboro, Jonesport)
Mummy berry cups are just getting started in this area, but some cups are large enough to be spreading spores. Please check your field to see if you have enough susceptible plants (more than 40% of random stems with flower buds are in the flower bud crown stage) to make an application of fungicide cost effective IF an infection period occurs.

IF your plants are at the susceptible stage AND your field gets FOG you may get an infection period. Please look at the chart in Factsheet #217 to check the length of time for plant wetness and temperature during that period.

ALL AREAS
There is a chance of new infection periods sometime from Tuesday through Wednesday morning with the storm coming through. This will depend on the length of time you have rain and fog in your field and the temperature during this time. At 65 F you need 8 hours of rain and fog, but at 72 to 80 F, which is forecasted for some areas Tuesday, the fungus only needs 3.5 hours of plant wetness to get infect the plants.

You will need to keep track of the approximate length of time of continuous rain and fog in your area and the temperature during the rain and fog to tell whether your field has had an infection period.

To control this disease you should apply fungicide within 72 hours of the START of the rain/fog period in your field. For example if the rain started in your area at 5 am on Tuesday you have until 5 am on Friday of this week to apply fungicide to kill off the infection and protect your plants.

Remember whether infection did occur in your field will depend upon 1) how far along the plants are in your field, 2) the actual temperature during, and length of time of rain or rain and fog in your field, and 3) of course, have you had mummy berry disease in your field in previous years .

Please check Factsheet #217 at the Wild Blueberry extension site (http://wildblueberries.maine.edu) for more information on the chance of infection depending upon temperature and length of leaf wetness. Please see Factsheet #219 for recommended disease control methods.