Mummy Berry Forecast Monday April 30th 2012

Lincoln, Knox and Waldo counties
Mature mummy berry cups producing spores were still present in Appleton and Liberty on Monday morning.  Pinheads were still found in Liberty, suggesting that mature cups are probably still present in most areas. No infection periods occurred over the weekend.   I expect the mummy berry cups will be finishing by the end of this week (hopefully).
Frost conditions occurred over Sunday night through to Monday in both Appleton and Belfast with the weather station recording average temperatures of 22F for about 2 hours.
The forecast is for rain on Tuesday through to Wednesday. Some fields may experience infection periods, since some mature cups are probably still present.


Hancock and Washington Counties
Mature mummy berry cups producing spores and numerous pinheads are present in Deblois, Wesley, and Jonesboro on Monday.   No infection periods occurred over the weekend. There were frost conditions in most fields Saturday and Sunday night.   Fortunately the weather forecast has only a low probability of rain in the next week.  I expect the mummy berry cups to be around into next week.

If you wish to see the data for the different weather stations please go to the link below.
On the AgriNET Dashboard website, the large graph shows all of the data from the different weather stations. Click on the icons at the top to get the  large graph to switch between showing Soil Temperature, Air Temperature, Leaf Wetness or Soil Moisture.
Click on the link for "Downloader and Graphs page" (top left) to get the graphs for individual weather stations.
Link to weather station data:
 http://www.grovision.com/AgriNET/ComServer/UofMaine/DashboardFrameset.htm

The map below shows where our weather stations are located. Click on the map for a magnified map.

Mummy berry forecast update Friday April 27th 2012

All areas
An infection period for the fungus to get into the plants was produced in most blueberry growing areas from Thursday through Friday.

If you applied fungicide on or after Thursday April 19th, your plants were probably protected during this infection period.

If you applied fungicide before Thursday April 19th, then you may wish to apply fungicide again to protect your plants.  You have 72 hours after the start of the infection period to apply fungicide to kill off any fungus that penetrated into the plants.

You will also need to consider if pollinators are present in your field when deciding whether or not to apply fungicide.  

The following times are approximate times when infection periods started in different areas.

Field Day start Time start Appleton 4/27 midnight Belfast 4/27 2:40AM N. Ellsworth 4/27 2:40AM Ellsworth 4/26 9:40PM Silby plain 4/27 3:00 AM Deblois 4/26 10:20 PM Montegail 4/26 10:20 PM Rocky pond 4/26 10:40 PM E. Machias 4/27 4:00 AM Meddybemps 4/27 12:40 AM Jonesboro 4/26 10:15 PM

Mummy Berry Blight forecast Thursday April 26, 2012

Knox, Lincoln and Waldo Counties
Numerous pinheads and mature cups are still present at Appleton, Liberty and Belfast.  Mature cups producing spores are probably present throughout this area.  As mentioned before, the plants are susceptible as long as cups are present in your field. 

Hancock and Washington counties
Numerous pinhead and mature cups are still present through out fields in these counties.
The fog the last 2 nights in many fields was NOT long enough to produce infection periods.  Temperatures on Thursday night did dip to 25 F for 2 to 3 hours in some fields, but this is not likely to cause cold damage to most plants.  Some clones may be very sensitive to cold but most should have not have damage.

All areas
The rain forecast for Thursday night through to Friday will likely produce another infection period for the fungus to get into the plants.
If you applied fungicide to your plants on or after Thursday April 19th, your plants will be protected during this coming infection period. 

I will update the forecast on Friday afternoon as to whether infection periods occurred or not.

Factsheet on Cold tolerance effects on flower buds and irrigation 
This study by  Dr. Paul Cappiello did not hold plants at different temperatures for long periods of time and did not examine the extensive diversity possible in clones.  It does provide a rough estimate of when flower buds are most susceptible to frost.
 
http://umaine.edu/blueberries/factsheets/irrigation/flower-primordia-development-stage/

Mummy berry Forecast Tuesday April 24th 2012

We have had a long infection period extending in some fields from Friday April 20th and in others from Saturday April 21st.  I have below the locations where we have weather stations and roughly when the infection periods started in those areas.

If you had applied fungicide on or after Monday April 16th,  your plants were protected during this last weekend and Monday, and  you do not need to apply fungicides at this time.

If your last application of fungicide was before Monday April 16th, you have up to 72 hours to apply fungicide (propiconazole or fenbuconazole) from the beginning of the infection period to kill of the fungus.  Considering the long period of infection the fungus had from Friday to Monday in some areas, if your last application of fungicide was before Monday April 16th, an application before  the end of Wednesday April 25th would still kill off some of the fungus that did get in your plants.

Weather station   Start of infection period
Appleton                 Sat. April 21 at 8pm

Belfast                     Sat.  April 21 at 8 pm

North Ellsworth     Sat.  April 21 at 7am

Ellsworth                Sat. April 21 at 7am

Aurora                     Sat. April 21 at 4pm

Deblois                   Fri. April 20 at 7pm

Montegail Pond     Fri. April 20 at 9pm

East Machias          Sat. April 21 10am

Meddybemps         Sat. April 21 6pm

UPDATE Mummy berry forecast for WASHINGTON COUNTY Fri. April 20

Washington county
Mummy berry pinheads were found in Meddybemps area on Thursday.  The plants are mostly susceptible in this area. 
There is a chance that mature cups ARE present in fields in this area.   The rain this weekend  may produce infection periods  this weekend in these fields.
 If you use fungicides, you may need to apply fungicide this weekend or early next week to control for mummy berry disease. 
I will put out updates as infection periods occur.

Mummy Berry Forecast for Thursday April 19th, 2012

Lincoln, Waldo and Knox  AND Southern Hancock counties
Mature mummy berry cups are actively producing spores in these counties.  Once your plants are have partially open buds they are susceptible to this fungus until the fungus stops producing spores.  Numerous mummy berry pinheads (not yet ready to produce spores) are still present on Thursday morning indicating that the fungus will be active for  a while.

The fog on Wednesday night was not enough to produce an infection period since the temperatures were too cold.
 
Northern Hancock and Washington counties
 Mature mummy berry cups producing spores have been found in early fields in Aurora, Deblois, Jonesboro, and Sam Hill. 

NO cups have been found in later, colder areas such as Rocky Pond and Meddybemps.

Please check your plants!  If there are greater than 40% of the stems with flower buds with the crown stage (F2) than your field has enough susceptible tissue to get infected.

For ALL areas with ACTIVE mummy berry cups

The rain forecast to occur this weekend starting Friday evening and through to some time next week  (perhaps until Tuesday night) is likely to produce multiple infection periods for the fungus to get into the plants.


Fungicide applications of propiconazole and fenbuconazole will protect your plants 7 days into the future from when you have applied them. Please plan accordingly.

If you have applied fungicide on or after Monday April 16th, your plants will be protected through the weekend infection periods and to at least next Tuesday morning.


If you have not applied fungicide yet or your last application was before Monday April 16th, you may need to apply fungicide this weekend or early next week depending upon when your application occurred and the number of infection periods.

April 17th 2012 Mummy berry forecast

Knox, Lincoln and Waldo counties
Fog in fields close to the coast may have caused an infection period for the mummy berry fungus to get into the plants last night.

In our Belfast site, approximately 4 miles from the coast (straight line distance), there was 10 hrs of fog (at an average temperature of 51F) which produced an infection period for the mummy berry fungus.

In Appleton, approximately 8 miles from the coast (straight line distance), did NOT have a long enough period of fog, only approximately 5.5 hours, so NO infection period occurred.

If your field typically has long periods of fogs you may have had an infection period in your field last night.

South Hancock county

Fog in fields near lakes or the coast may have caused an infection period for the fungus to get into the plants last night.
In our two sites, near Branch lake and in Ellsworth,  11 to 16 hours of fog (at an average temperature of 48.5 F) produced an infection period for the mummy berry fungus.

If your field typically has long periods of fogs you may have had an infection period in your field last night.

For fields where an infection period likely occurred:

If you have applied fungicide (propiconazole or fenbuconazole) to your plants after Monday April 9th, then your plants were protected during this infection period last night.

If you have not applied fungicide or applied it before Monday April 9th, then you have until 7 pm on Thursday April 19th to apply fungicide to kill off any infection that may have occurred.

Northern Hancock and Washington counties
Mature mummy berry cups have not yet been found in Aurora, Deblois, Jonesboro, East Machias, or the barrens so any fog that occurred last night did NOT produce infections since there are NO spores present yet.  I expect mature cups to be present soon.

Mummy Berry Forecast for Monday April 16, 2012

When are my plants susceptible to mummy berry fungus? 
Your plants are susceptible to infection by the mummy berry fungus from when they have 40% of the stems at the crown stage throughout their development.  The flowers and leaves are susceptible at every stage of development past when the bud scales have opened up enough to expose green tissue.  While mature mummy berry cups are producing spores in a field, there is the risk of infection.  Fortunately the fungus does not produce spores for the whole season.  In different years, mature cups have been found from 1 week to 3.5 weeks in a field, depending upon the weather.   Data are being collected this year which will hopefully help predict when cups mature and how long they remain in a field.


Lincoln, Knox, Waldo counties
Most plants are now susceptible and mature mummy berry cups producing  spores have been found in Liberty and Appleton.  Numerous pinheads (not yet producing spores) are present indicating the threat of mummy berry infection will still be around for a while.

There were no infection periods over the weekend reported from Appleton and Belfast.   Rain is not predicted until Friday, but fog may produce an infection period for the fungus.  In the Belfast field, fog was present for 7 hours but temperatures were too cool to produce an infection period.

If your field typically has fog, you may have an infection period this week. 

South Hancock county
Plants are susceptible and cups should be present in field in these areas by this time. 
There was an infection period reported at both north Ellsworth and in Ellsworth on Sunday night starting from 6pm to 10pm and continuing until about 8am Monday morning.

If you have NOT applied fungicides to your field, you have until approximately 6pm on Wednesday  to apply propiconazole or fenbuconazole to kill off any infection that may have occurred from the Sunday night infection period. 
 
If you have applied fungicide on or after Sunday April 8th, your plants were protected during this infection period.

Fog may produce more infection periods this week. 


Northern Hancock and Washington Counties
Mummy berry pinheads have been found in fields in Aurora, Deblois, Jonesboro, and Montegail pond. 
Plants are approximately 25 to 30% with susceptible flower buds (at the crown stage).  With the warm weather predicted for this week, we will have mature mummy berry cups and plants at the fully susceptible stage this week.

Fog can produce conditions for an infection period for the fungus to get into the plants.  The conditions for infection did occur on Sunday night in many areas, BUT there were likely no spores present since mature cups have not been found yet.  Therefore there was no infection on Sunday night. 

If your field typically has fog and your plants are early, you may have an infection period this week.

Mummy berry forecast for Friday, April 13th, 2012

What does an "infection period" mean? 
Once mature cups are present in your field, they will be actively producing and shooting off spores into the air that will land on your plants.  The spores will be produced as long as there are mature cups in the field. The spores on the plants will not be able to infect unless there is an "infection period" which is when there is a long enough time of wetness on the plants for the fungal spores to germinate and penetrate into the plant.  The length of time the wetness is required for germination and penetration of the spores depends upon the air temperature,  with cooler temperatures requiring longer wetness periods.   Dew typically does not last long enough on plants; only rain or fog can produce infection periods.

Knox, Lincoln and Waldo counties
Mature cups producing spores have been found in Liberty in a wet field.  I suspect other fields will also have cups present in their fields.
Most plants are probably susceptible at this point.  An Appleton field had approximately 75% of their plants at flower stage F2 or beyond on Thursday.

The scattered showers this past week did not produce an infection period for any of the locations monitored.  The bit of rain that has fallen and the warm weather predicted this weekend is likely to get cups developing for next week.


The scattered showers predicted this weekend in this area are unlikely to be cause wetness on the plants long enough for an infection period for the fungus to get in the plants.

Hancock South

Around Ellsworth, no cups have been identified in our 2 fields yet, but cups may be present in wetter fields.  Since there are beginning of pinheads in Deblois, I think there may be earlier fields in this area that do have cups.  There were borderline conditions for an infection period from Thursday around 7 to 9pm to Friday morning from 4am to 8am.  The leaf wetness was just long enough to maybe cause an infection period. What was required at the average temperature at one location during that time was 12.5 hours of wetness to get an infection period and we got exactly 12.5 hours of wetness.

If you have a wetter field, you may have cups in your field and may have experienced an infection period last night.  


The weather forecast for this weekend suggests it is unlikely there will be conditions for an infection period  until the wet period next week.   I expect mummy berry cups to be developing this weekend.

Hancock North and Washington Counties
Very young pinheads (not producing spores yet) have been found in Aurora and Deblois on Thursday evening and Friday.  Plants were approximately 15% susceptible in fields in Deblois.   With the warmer weather this weekend, I expect mature cups will be present next week.

Mummy berry forecast Monday April 9th, 2012

Lincoln and Knox counties
There were borderline conditions for an infection period in the Appleton and Liberty area. The leaf wetness was almost long enough to provide an infection period, but was short approximately 1/2 hour.   In a wet field in Liberty, mummy berry pinheads were seen on Thursday.  Plants in the area were susceptible, BUT I think it unlikely there was an infection period in the Liberty and Appleton area on Sunday night.  There was minimal conditions for infection with cups only just getting started to produce spores, and borderline conditions for the fungus to get into the plants.

Wet fields south of  these areas may have had cups open by this weekend, and so may have experienced an infection period.  I do not have any growers in that area monitoring mummy berry plots so I can only speculate.  

Waldo and southern Hancock and Penobscot counties
Most fields have not shown any cups or even pinheads by this past weekend, which is probably due to the dry conditions.  After the rain and snow mix this weekend, I expect mummy berry cups will start to appear in other fields.  In Appleton, a pinhead was just starting this morning (Monday) after seeing nothing before this past weekend.  I expect pinheads starting in Belfast soon and then around Ellsworth. 
Plants are at the susceptible stage (40% of stems with crown flower buds) in many of the fields in these areas.

Northern Hancock and Washington counties
Plant flower buds are just starting to swell.  Plants seen on Friday and Saturday were not at the susceptible stage with only the earliest clones with flowers at F1 (just opening of bud scales).
No cups have been seen in these areas

Mummy berry season is here. 2012

Lincoln, Knox, Waldo AND south Hancock 
Plants have buds at the susceptible stage in Appleton and Ellsworth.  Both sites were very close to over 40% of their flower buds at F2 (crown stage, see previous forecast for pictures) on Tuesday April 3rd so they are likely at that stage now.
Mummy berry cups were found in a wet field in Liberty on Thursday, April 5th. They have not yet been found in drier fields in Appleton and near Ellsworth as of Friday April 6th.   IF you have a field with wet, heavier soil in the above counties, you may have mummy berry cups present in your fields.   I suspect most drier fields will not have cups yet.

Some areas in these counties are predicted to get a frost on the night of Saturday, April 7th.  


Maine is forecasted to get rain/snow showers from Saturday night through Monday and maybe beyond into Tuesday.  The weather conditions may have enough rain and warm enough temperatures to cause infection periods in fields with wet, heavy soil and a history of mummy berry disease.  The plants in your field would also need to have over 40% of the stems with susceptible flower buds (see previous forecast for information on how to calculate this) for applications of fungicides to be cost effective.  Unless your fields have these conditions, I am not recommending applications of fungicides yet in these areas. 
If  you apply fungicides, please follow recommendations in the Fact Sheet # 219-Disease Control Guide for Wild Blueberries.

The rain and snow is likely to start the mummy berry germination even in dry fields, so I expect cups in these areas by the end of next week. 

Northern Hancock and Washington Counties
No mummy berry cups have been seen in plots examined in these areas.
The plants are just getting to F1 (bud break) and only the very earliest fields have flowers at F2 (crown stage).  The rain and snow this weekend will provide moisture for germination of mummy berries.  If the weather is warm, cups may start to appear in early fields this coming week.

I will update this forecast on Monday, April 9th.

Mummy Berry Season is coming! 2012

Waldo, Lincoln, Knox counties

It is time to start looking at your plants for flower bud opening and for cups to start appearing this week if you have a mummy berry plot in these counties. After the unusual warm weather 2 weeks ago,  the plants have moved along to just starting to open their bud scales on their flower buds.  Plants in Appleton on Sunday were mostly at F1 stages (buds scales opening, see pictures below. 

Mummy berry cups were not seen in Appleton on Sunday.  I expect both plants to become susceptible and cups to start opening in these areas within the next week.

I have put out weather stations in fields in Appleton and Belfast, and growers are observing mummy berry plots in Appleton.If you have a mummy berry plot I would like to hear how your cups are developing. 

Applications of fungicide are more cost-effective when 40% or more of the stems have susceptible flower buds.  

To determine the percentage of plants in a field that are susceptible

1) Collect 20 stems randomly in a transect across the field

2) Count the number of stems that have any flower buds at F2 stage (flower buds are easier to see than leaf buds) 

3) Multiple the number of stems with susceptible buds by 5 (if you looked at 20 stems) to get the percentage of susceptible stems in your field.

Seanna Annis