Disease forecast for Mon. May 23rd 2011

Mummy berry Forecast - Northern Hancock and Washington counties

Mummy berry cups were not found at Deblois, Montegail, Jonesport or Jonesboro by Friday May 20th so the mummy berry infection season is finished for 2011.

For controlling disease in the future, it is important to know what you disease you have in your field.

Mummy berry symptoms

You will see symptoms of mummy berry blighted leaves and flowers at this time (see picture below). Any infections you see now occurred at least eight to nine days ago. Spores produced on the dead leaves and flowers will infect healthy flowers to produce the mummy berries seen at harvest. These spores cannot cause new infections that would kill leaves or flowers.

- Only some flower clusters on stem will be infected

- Open and closed flowers will show symptoms

- Only some leaves will be infected, look dead and typical in a crook shape

- Key Symptom – Gray powdery spores (in yellow circles) at base of affected flowers and leaves

Botrytis blossom blight

If your field usually gets Botrytis blossom blight, now is the time to start looking for early symptoms (see pictures below). Symptoms of dead flowers or leaves with thin black hairs sticking out of them may be found on flowers of early blooming blueberry plants and the dead leaves of red sorrel, also called Sheep’s sorrel (Scientific name: Rumex acetosella). The small dark hairs (use a magnifying glass or reading glasses to see them) are always found if you have Botrytis blossom blight. IF you have dead blossoms and they do NOT have black hairs then your flowers were likely killed by mummy berry blight. I have not recorded any frost in the past weeks, so frost is unlikely to be a cause of dead flowers.

- Only some flower clusters on a stem will be affected

- Mostly affects almost open and open flowers

- Leaves can also show disease symptoms

- Key Symptom – black hairs, some with gray tips, (in yellow circles) extend off of infected flowers and leaves

Frost damage for comparison (see pictures below)

Frost has not been recorded in any areas I am tracking this year. It is unlikely to have caused flower damage this year.

- All flower clusters on stem typically are affected

- Closed flowers not affected as much

- Leaves can be damaged, but typically only tender tissue

- Key symptom: Often all flower clusters on a stem are affected

Disease forecast for Thurs. May 19th 2011

MUMMY BERRY FORECAST
Northern Hancock and Washington counties

Mummy berry cups were found at Deblois, Montegail pond (north of Columbia Falls) and at Jonesport along the coast on Monday May 16^th and Tuesday May 17^th this week. Cups are NO longer present in Deblois and Montegail pond. Active cups were still producing spores in Jonesport on Thursday May 19th. Later fields are likely to still have active cups for the next few days.

This means most fields in this area were likely to have had infection periods on Monday May 16^th (reported in the last forecast) and Tuesday May 17^th but only later fields would continue to have a chance of mummy berry infection after Wednesday May 18^th.

There was an infection period throughout this area from Tuesday May 17^th 8pm through Wednesday May 18^th 9 to 10am. If you applied fungicide on or after Wed. May 11^th your plants would have been protected through this infection period. If they were not protected you would have until Friday evening to apply fungicide to kill off any infection, but considering no future infections will occur this is probably not necessary.

There was an infection period in many later fields overnight from Wed. May 18^th at 8pm or later through to Thursday May 19^th at 11am to noon. If you applied fungicide on or after Thursday. May 12^th your plants would have been protected through this infection period.

If your plants were not protected and you have a later field, then you have until Friday May 17^th evening to apply fungicide and kill off any infection that has occurred in this latest infection period starting on Tuesday May 17^th. This application would also protect your plants which are likely to be exposed to more infection periods starting tonight and continuing possibly into the middle of next week.

MUMMYBERRY SYMPTOMS

You will start to see symptoms of mummy berry blighted leaves and flowers at this time. I would like to remind you that these were caused by infections that occurred eight to nine days ago and there is no point to applying fungicides after the mummy berry cups are done since the spores produced on the dead leaves and flowers can NOT infect and kill leaf and flower buds. The spores on the infected flower and leaf buds will be carried to some of the healthy flowers and produce mummified fruit at harvest. Applications of fungicide have not been proven to be effective in lowbush blueberries to control this second type of infection of healthy flowers.

BOTRYTIS BLOSSOM BLIGHT

If your field usually gets Botrytis blossom blight, now is the time to start looking for early symptoms. Symptoms of dead flowers or leaves with thin black hairs sticking out of them may be found on flowers of early blooming blueberry plants and the dead leaves of red sorrel, also called Sheep’s sorrel (Scientific name: Rumex acetosella). The small dark hairs (use a magnifying glass or reading glasses to see them) are always found if you have Botrytis blossom blight. IF you have dead blossoms and they do NOT have black hairs then your flowers were likely killed by mummy berry blight. I have not recorded any frost in the past weeks, so frost is unlikely to be a cause of dead flowers

Mummy berry forecast Monday May 16th 2011

Infected leaves and flower buds will continue to develop normally up to 8 days after infection. Eight to nine days after infection, the infected leaves and flower buds will die and produce grayish masses of spores. There is no point of applying fungicides after the mummy berry cups are done since the spores produced on the dead leaves and flowers can NOT infect and kill leaf and flower buds. The spores on the infected flower and leaf buds will be carried to some of the healthy flowers and produce mummified fruit at harvest. Applications of fungicide have not been proven to be effective in lowbush blueberries to control this second type of infection of healthy flowers.

Knox, Warren, Lincoln, southern Hancock counties

Mummy berry cups are likely finished in these areas and so mummy berry infection will no longer occur to the developing leaf and flower buds.

Northern Hancock and Washington counties

Mummy berry cups have been found in fields at Deblois, Montegail pond (north of Columbia Falls) and at Jonesport along the coast. Later fields are likely to have had cups throughout the past weekend and will continue to have cups into this week.

There was an infection period in fields that still had mummy berry cups starting on Saturday May 14^th at 7pm to 9pm through Monday May 16^th morning and this is continuing into Monday.

If you applied fungicide on or after Monday May 9^th , then your plants will be protected through this latest infection period.

If your plants were not protected, then you have until Tuesday May 17^th about 7pm to apply fungicide and kill off any infection that has occurred in this latest infection period starting on Saturday May 14^th.

With the weather forecast for the rest of the week, there will likely be more infection periods this week. Unfortunately, the plants are susceptible for as long as there are mature mummy berry cups in your field.

Mummy berry forecast Thurs. May 12th 2011

Knox, Lincoln, Waldo and southern Hancock counties

Mummy berry cups were likely present in cooler, later fields from Monday May 9^th through Wednesday May 11th. In most fields, the cups will likely have finished up later on Wed. May 11^th. On Thurs. May 12, the cups were done in Union, Liberty and Belfast areas. I am estimating that most cups are done in these areas since the Belfast field is a later, wetter field.

There were infection periods starting on Monday and Tuesday. There was an infection period from the evening of Monday May 9^th through the morning of Tuesday May 10^th. There was another infection period on Tuesday May 10^th 11am to noon through to Wed. May 11^th early morning to 9am .

If you have applied fungicide on or after Wed. May 4^th your plants would have been protected during these infection periods.

If your plants were not protected and you still had cups in your field through Wed. May 11^th, then you have until Thursday May 12^th evening to apply fungicides to kill off any infections on Monday, and until Friday May 13^th afternoon to kill off any infections that happened on Tuesday.

Northern Hancock and Washington counties.

There were active mummy berry cups from Monday May 9^th through Wednesday May 11^th in Deblois and Jonesboro, and later, cooler fields likely still have active mummy berry cups.

Infection periods started on Monday and Tuesday of this week. The first infection period occurred from Monday May 9^th 2 to 3pm through Tuesday May 10^th 6 to 7am. The second infection period occurred Tuesday, May 10th from 8 to 9am through Wednesday May 11^th midnight to 7am.

If you applied fungicide on or after Wednesday May 4^th morning your field was protected for all of the infection periods from Monday through Wednesday.

If your plants were not protected, then if you have applied fungicide before Thursday May 12^th your plants will be protected for all of the infection periods.

Applications of fungicide before Friday morning will kill off any infection that occurred in the 2^nd infection period from Tuesday to Wednesday.

Applications of fungicide after Friday morning will protect plants into the future, but will not be within the time to kill off any infections that occurred in these last infection periods.

Mummy berry forecast for Mon. May 9th 2011

Knox and Lincoln counties

Mummy berry cups were present on Thursday at Union so they likely lasted over the weekend.

There was a chance of an infection period in some areas with rain and then fog from Thursday May 5^th night around 5pm to Friday May 6^th early in the morning.

Otherwise there were no infection periods during the weekend in these counties unless you have a field with heavy fog that lasted at least 8 hours.

It is too late to apply fungicide now to kill off any infections that occurred on Thursday. I would only recommend applying fungicide if you are sure your field had fog for more than 8 hours one evening this weekend AND you have not applied fungicides since Saturday April 30^th.

Waldo and south Hancock counties.

Cups were still present on Monday in Belfast and Liberty and are probably still active throughout this area. I expect the cups are likely to finish up this week. The rain was not long enough on Thursday night to cause an infection period in this area.

There was an infection period from Saturday May 7^th, 2011 8pm to 9m through to Sunday May 8^th from 7 to 9am in these areas.

If you had applied fungicide on or after Saturday April 30th then your plants would be protected during this infection period.

If your plants were not protected then you have until Tuesday May 10^th about 8pm to apply fungicides and kill off infection from the last infection period.

Northern Hancock and Washington counties.

There are still mummy berry cups being produced at Deblois and Jonesboro, and cups are likely to be producing spores at Jonesport and other later fields.

An infection period occurred from Thursday May 5^th 3pm to 6pm through to Friday 8 to 9am in Deblois and Jonesboro. In Jonesport, the temperatures were cooler so the conditions were borderline for producing an infection period and only some fields may have had an infection period.

There was an infection period in SOME areas with heavy fog from Sat. May 7^th 11pm to Sunday May 8^th at 7am. This infection period was seen in Jonesboro and Jonesport, but not at our site in Deblois.

The fog was not long enough overnight from Sunday, May 8^th to Mon. May 9^th with the cool temperatures to allow the fungus to infect the plants so there was NOT an infection period.

It is too late to apply fungicide now to kill off any infections that occurred on Thursday night.

If you applied fungicide on or before Sat. May 7^th your field was protected in the possible infection period from Sat. May 7^th to Sun. May 8^th.

If your plants were not protected AND your field is one that typically gets heavy fog, then you have until Tuesday, May 10^th at 11pm to apply fungicide and kill off any infection.

Mummy berry forecast for Thurs. May 5th 2011

Lincoln, Knox, Waldo and South Hancock counties

Mummy berry cups are still present and were actively shooting out spores this week in Belfast, Union and Liberty. New immature cups were present today (Thursday) in Belfast and Liberty so spore production will be continuing for a while. The cups are likely to continue being active over the weekend and possibly into early next week. I do not have a mummy berry patch south of Union, so to be cautious, I am considering the cups are still active in southern Knox and Lincoln counties.

There was a 32 to 34 hours long wet period producing a long infection period throughout this area from Tues. May 3^rd approximately 11pm to midnight through to Thurs. May 5^th 7 to 8am. The rain/drizzle/fog is also predicted to continue in this area through part of Thursday night. The forecast for west of the Penobscot river is for dry weather on Friday and a low chance of rain over the weekend, so it is unlikely there will be more infection periods this weekend, unless you have a field that regularly gets more than 8 to 9 hours of fog.

If you applied fungicide on or after Fri. April 29^th then your plants will have been protected during this last infection period and you do NOT need to apply fungicide for this last infection period.

If you last applied fungicide before Fri. April 29^th then your plants were not protected during this last infection period. If you then apply fungicide (propiconazole or fenbuconazole) before Fri. May 6^th at 11pm, the fungicide will kill of any infection that may have occurred in this last infection period AND your plants will be protected for a further 7 days.

Southern Penobscot, northern Hancock and Washington counties

Active mummy berry cups and new immature cups were present at Deblois and Jonesboro, but had not started yet in Jonesport. In cooler, later fields, cups have not yet started but elsewhere in this area cups are actively producing spores and are predicted to continue through the weekend and into next week.

There was a wet period from Monday, May 2^nd starting at 8pm to 10pm and continuing through to Tuesday, May 3^rd at 6 to 7am that did NOT produce an infection by the mummy berry fungus since it was too short a length of plant wetness at the average temperature of 37 to 39F.

There were infection periods from Tues. May 3^rd at 7pm to Wed. May 4^th at 10am AND from Wed. May 4^th at 4pm to Thurs. May 5^th 9am and possibly continuing.

The rain/drizzle/fog is also predicted to continue in this area through part of Thursday night and perhaps into Friday. The forecast for east of the Penobscot river is for a chance of rain through Friday and Saturday which may produce infection periods.

If you applied fungicide on or after Fri. April 29^th then your plants will have been protected during this last infection period and you do NOT need to apply fungicide for this last infection period.

If you last applied fungicide on Wed. April 27^th or Thurs. April 28th then your plants were protected Wed. of this week but will not be protected for the infection period occurring today (Thursday). If you apply fungicide before Sat. May 6^th at 4pm, the fungicide will kill of any infection that may have occurred in this last infection period AND your plants will be protected for a further 7 days.

If you last applied fungicide before Wed. April 27^th then your plants were not protected during these last infection periods. If you apply fungicide before Fri. May 6^th at 7pm, then the fungicide will kill off any infection that may have occurred and your plants will be protected for a further 7 days.

Mummy berry forecast for Mon. May 2nd 2011

Lincoln, Knox, Waldo, and western Hancock counties
Mummy berry cups ares still present in these areas.
There was another infection period from Thurs. April 28th about 2pm through Fri. April 29th at 4 to 6am depending upon the field.

There was a wet period in Stockton Springs and surrounding areas overnight from Sun. May 1st to Mon. May 2nd, but due to the cool temperatures (33F) this did NOT cause an infection period.

If you applied fungicides after April 22nd, then your plants would have been protected during this last infection period. If your plants were NOT protected, then you would have needed to apply fungicides by Sun. May 1st 2pm to kill off any fungus that penetrated your plants during this last infection period.

There is wet weather predicted for this area from Tuesday morning through Thursday and this will likely result in multiple infection periods.

Downeast- eastern Hancock and Washington counties
Mummy berry cups are present in Deblois, Jonesboro and at Montegail pond in the barrens. Mature mummy berry cups have not been found at Jonesport yet, but are likely to start in this and other cooler, later fields this week.

There was a very long infection period from Wed. April 27th at 5 to 6pm through until Fri. April 29th at 7 to 8am OR two infection periods within this time period with a short dry period on Thursday.

There was a wet period overnight from Fri. April 29th to Sat. April 30th, but this did NOT cause an infection period because the wetness was too short for the cool temperatures (42 to 47F).

If you applied fungicides after April 22nd, then your plants would have been protected during these last infection periods. If your plants were NOT protected, then you would have needed to apply fungicides by Sat. April 30th 4pm to kill off any fungus that penetrated your plants during these last infection periods.

There is wet weather predicted for this area from Tuesday through Thursday and this will likely result in multiple infection periods.

If you have a cooler, later field, you should check your plant development before applying fungicides. If you have less than 40% of your flower buds at the susceptible stage, then you do not have very much plant tissue to be infected by the fungus, AND you do not have much young tissue to absorb the fungicide you apply. The fungicide will absorb better through new leaf and flower tissue than through the stems and bud scales around unopened leaf and flower buds.

If you have a mummy berry plot, I would like to know how it is progressing, please contact me at sannis@maine.edu.

Mummy berry forecast for April 28th 2011

WALDO, KNOX, LINCOLN, HANCOCK
Mature cups that would be shooting out spores have been present this week in Union, Belfast and Liberty.
Plants were at the susceptible stages in most of these fields. If you have a slower, cooler field and your plants were NOT yet at 40% of the stems with susceptible flower buds on Thursday April 28th, then your field may have escaped most of the recent infection periods this week.

Multiple mummy berry infection periods have occurred in Lincoln, Knox, Waldo and Hancock counties since Monday. The exact timing of the start and end of an infections period depended upon the field.
Infection periods occurred from:
Mon. April 25th 6 to 7pm through to Tues. April 26th 11am to noon
Tues. April 26th 5 to 7pm to Wed. April 27th 6 to 9 am
Wed. April 27th 4pm to Thurs. April 28th morning.

If you have applied fungicide within 7 days of the start of an infection period your plants would have been protected.
If your plants were NOT protected during one of the recent infection periods, you can apply fungicides with 72 hours of the start of an infection period and kill off any fungus that penetrated during that infection period.

Downeast (northern Hancock, Washington counties)
We have found one mature cup in Deblois on Wednesday April 27th, but only pinheads at Jonesboro. The fields in Deblois were not at 40% susceptible stems on Wednesday, but Blueberry Hill farm field was at 70% susceptible stems. If you have a warmer, earlier field than your plants may have been exposed to an infection period in this past couple of days.

We found no germination of mummy berries and the plant are not ready yet at Jonesport, so the wet weather would NOT have created infection periods because the fungus was not present.

There were infection periods through out this region, but to determine if you need to apply fungicides you should check the development of your plants. Please see the last 2 forecasts for information on how to evaluate your plant development.

Possible infection periods if cups were present in your field and the plants were at least 40% susceptible:
Wed. April 27th 2 to 4am through Wed. April 27th noon
Wed. April 27th 4 pm through Thurs. April 28th morning.

If your plants were NOT protected during one of the recent infection periods, you can apply fungicides with 72 hours of the start of an infection period (so by Saturday, April 30th morning) and kill off any fungus that penetrated during that infection period.

If you are using the calendar method for timing fungicide applications you will want to apply fungicides before an infection period when your plants are at 40% susceptible stems.

For recommendations on fungicides and biopesticides to control mummy berry disease please use the Disease Control Guide for 2011, Bulletin 219.

Infection period Saturday April 23rd thru April 24th

WALDO, KNOX, LINCOLN, Southern HANCOCK
Mummy berry infection periods have occurred in most areas of Lincoln, Knox and southern Waldo county. An infection period also may have occurred in southern Hancock county.
Cups were found on Monday in Union, Liberty and Belfast. Cups had developed over the weekend in Belfast, which tends to be a week later than fields in Union for plant development. If you have a warmer, earlier field in those area, you probably did have some cups for the infection period on Saturday. If you have a cooler, later field you may have avoided the infection period. On Monday April 25th, 70% of the stems in Belfast had susceptible buds up from 30% last Thursday. Most areas that are south of Belfast will have enough susceptible stems to need protection.

The infection period in these areas started on Saturday April 23rd from approximately 10am to noon depending upon the field and ended on Sunday, April 24th from 6am to 8am, again depending upon the field.
If you have applied fungicide between April 16th and April 22nd then your plants would have been protected for the infection period on Sat. April 23rd.
If you have NOT applied fungicide, then you have until approximately Tuesday April 26th at noon to protect your plants.

The wet, warm weather forecast for much of the state in the next 4 days will provide more opportunities for infection periods to occur.

Please follow all recommendations in the Disease Control Guide for 2011, Bulletin 219.

DOWNEAST
Mummy berries are still only at the pin head stage and are not producing spores yet. Plants do not yet have enough open flower and leaf buds to have susceptible tissue to be infected. I predict cups will start to open this week with the warm, wet weather. Cups do open before the plants have enough susceptible tissue. Please check your field for how far along your plants are in development (see below). If 40% of the stems have susceptible flower buds than you have enough exposed tissue to make an application of fungicide effective.

Checking the development of your plants
To find the percentage of stems with flower buds at the F2 stage (seen to your right). Walk across your field and randomly collect 20 stems. If 8 out of 20 stems have flower buds at F2 stage than your plants are far enough along to become infected. Flower and leaf bud development follow each other closely and flower buds are much easier to determine when they are susceptible.

If you have a mummy berry patch I would like to hear how it is progressing, particularly if you are in Hancock county as I have no sites in that area.