Posts Tagged ‘Maine sweet corn’

Sweet Corn IPM Newsletter No. 7 – August 9, 2013

Friday, August 9th, 2013

Sweet CornSweet Corn IPM Newsletter No. 7 – August 9, 2013

For full page print version, please see link at the bottom. Click on photos to enlarge.

CORN PEST PRESSURE REMAINS LIGHT IN MOST FIELDS

Corn Earworm, Fall Armyworm & European Corn Borer Damage Low

SITUATION
Another week of fairly light insect pressure in most locations this week, thanks to a relatively stable weather pattern. Storm fronts coming across from the Midwest or the South could quickly bring higher moth counts to the state, but for now most farms are enjoying a light spray schedule for this time of the season.

European corn borer: Moth catches were very low across the state this week. No silking fields exceeded the threshold of 5 moths per week. European corn borer feeding damage was over threshold in a pre-tassel field in Oxford this week. When European corn borer and fall armyworm damage are found in the same field, the damage is combined and the spray threshold is lowered to 12% injury. This week a field in Sabattus exceeded the combined injury level.

Corn earworm: Moth counts continued to be low in all locations this week and many fields required no additional protection. A 5-day spray interval was recommended for one site in Cape Elizabeth, Charleston, one site in Dayton, and New Gloucester. A 6-day spray interval was recommended for silking fields in Biddeford, Garland, and Nobleboro.

European Corn Borer Entry Hole

European Corn Borer Entry Hole, photo by David Handley

Fall Armyworm Eggs on Corn

Fall Armyworm Eggs on Corn, photo by David Handley

Fall armyworm: Most sites have still not seen significant fall armyworm damage this season. Fall armyworm moths were caught only in Biddeford, one Dayton site and in Nobleboro this week. Biddeford and Dayton exceeded the weekly threshold of three moths for silking corn. A single moth was caught in Nobleboro. Our site in Biddeford was the only location where fall armyworm feeding damage on younger corn exceeded the spray threshold.

Squash vine borer: Moth counts continued to drop this week. Squash vine borers were caught in Cape Elizabeth and Dayton, but the threshold of five moths per week was not exceeded at either of these locations.

Plectosporium blight: Symptoms of Plectosporium have also been found in pumpkin fields over the past two weeks. This fungus disease causes white flecking in the surface of the fruit and leaves, leading to collapse of the plants and fruit rot. See the New England Vegetable Management Guide for details. The fungicides Quadris®, Maneb®, Bravo®, Cabrio® and Flint® are labeled for use on pumpkins to control Plectosporium.

Plectosporium blight on pumpkin

Plectosporium blight on pumpkin, photo by Mark Hutton

Male Spotted Wing Drosophila

Male Spotted Wing Drosophila, photo by Griffin Dill. Actual size: 2-3 mm.

Spotted Wing Drosophila Alert: Fruit fly counts were quite variable this week, with some sights catching few or no flies while one had the highest count of the season. Flies were caught in Wells, Cape Elizabeth, Limington, New Gloucester, Gray, Monmouth, Bowdoinham and Corinna. Most traps had one to three flies in them. The exception was the Bowdoinham site, which had over 200 flies for the week. The tiny larvae of these flies can quickly destroy ripening soft fruit such as raspberries and blueberries. Once spotted wing drosophila is found in your area, fruit should be protected with a recommended insecticide. Regular and repeated treatments are usually needed to keep fruit from becoming infested. Visit our Spotted Wing Drosophila blog for more details.

Sincerely,

David T. Handley
Vegetable & Small Fruit Specialist

Highmoor Farm                    Pest Management Office
P.O. Box 179                          491 College Avenue
Monmouth, ME 04259      Orono, ME 04473
207.933.2100                       1.800.287.0279

Sweet Corn IPM Weekly Scouting Summary

Location CEW
Moths
ECB
Moths
FAW
Moths
%Feeding
Damage
Recommendations / Comments
Auburn 0 0 0 6% No spray recommended
Biddeford 3 0 5 19% 6-day spray interval recommended on all silking corn
Cape Elizabeth I 0 0 0 3% No spray recommended
Cape Elizabeth II 5 0 0 5-day spray interval recommended on all silking corn
Charleston 4 3 0 0% 5-day spray interval recommended on all silking corn
Dayton I 6 1 6 7% 5-day spray interval recommended on all silking corn
Dayton II 0 1 0 8% No spray recommended
Farmington 0 0 0 0% No spray recommended
Garland 3 0 0 0% 6-day spray interval recommended on all silking corn
Levant 0 1 0 3% No spray recommended
Lewiston 0 0 0 0% No spray recommended
Livermore Falls 0 0 0 3% No spray recommended
Monmouth 0 0 No spray recommended
New Gloucester 7 3 0 5-day spray interval recommended on all silking corn
Nobleboro 2 0 1 5% 6-day spray interval recommended on all silking corn
No. Berwick 1 0 0 2% No spray recommended
Oxford 0 1 0 24% One spray recommended for ECB feeding
Palmyra 0 0 0 2% No spray recommended
Poland Spring 0 0 0 7% No spray recommended
Sabattus 0 0 0 18% One spray recommended for ECB+FAW feeding
Wales 0 0 0 5% No spray recommended
Warren 0 0 0 2% No spray recommended
Wells I 1 0 0 2% No spray recommended
Wells II 0 0 0 1% No spray recommended

CEW: Corn earworm (Only fresh silking corn should be sprayed for this insect.)
ECB: European corn borer
FAW: Fall armyworm

Corn Earworm Spray Thresholds for Pheromone Traps

Moths caught per week Moths caught per night Spray interval
0.0 to 1.4 0.0 to 0.2 No spray
1.5 to 3.5 0.3 to 0.5 Spray every 6 days
3.6 to 7.0 0.6 to 1.0 Spray every 5 days
7.1 to 91 1.1 to 13.0 Spray every 4 days
More than 91 More than 13 Spray every 3 days

Thresholds apply only to corn with exposed fresh silk. Lengthen spray intervals by one day if maximum daily temperature is less than 80°F.

European Corn Borer Thresholds
Whorl stage: 30% or more of plants scouted show injury.
Pre-tassel-silk: 15% or more of plants scouted show injury.
Silk: 5 or more moths caught in pheromone traps in one week.

IPM Web Pages:
http://extension.umaine.edu/ipm/
http://www.pestwatch.psu.edu/sweet_corn.htm
http://www.umass.edu/umext/ipm/

Where brand names or company names are used it is for the reader’s information. No endorsement is implied nor is any discrimination intended against other products with similar ingredients. Always consult product labels for rates, application instructions and safety precautions. Users of these products assume all associated risks.

Published and distributed in furtherance of the Acts of Congress of May 8 and June 30, 1914, by the University of Maine Cooperative Extension, the Land Grant University of the State of Maine and the U.S. Department of Agriculture cooperating. Cooperative Extension and other agencies of the U.S.D.A. provide equal opportunities in programs and employment.

Sweet Corn IPM Newsletter No. 6 – August 2, 2013

Friday, August 2nd, 2013

Sweet CornSweet Corn IPM Newsletter No. 6 – August 2, 2013

For full page print version, please see link at the bottom. Click on photos to enlarge.

A FAIRLY QUIET WEEK FOR CORN PESTS

Corn Earworm, Fall Armyworm & European Corn Borer Pressure Remains Light

SITUATION
Weather patterns continue to keep insect pressure fairly light in most locations. Harvest continues to look good, although maturity and supply has been spotty. Keep an eye out for late season diseases, especially corn rust, in younger fields.

European corn borer:  Moth catches in southern Maine were low again this week. Only silking fields in New Gloucester, Charleston and Palmyra were over the threshold of 5 moths per week, but the Charleston site is on a spray schedule for corn earworm, so no additional sprays were required. European corn borer feeding damage was over threshold in a pre-tassel field in Oxford this week. When European corn borer and fall armyworm damage are found in the same field, the damage is combined and the spray threshold is lowered to 12% injury. This week a field in Biddeford exceeded the combined injury level.

European Corn Borer Larva on Ear

European Corn Borer Larva on Ear, photo by David Handley

Corn Earworm Feeding on Corn

Corn Earworm Feeding on Corn, photo by David Handley

Corn earworm:  Moth counts are low in all locations this week and most locations did not require protection. A 5-day spray interval was recommended for Charleston and one site in Dayton. A 6-day spray interval was recommended for silking fields in the other Dayton site, as well as Garland, Sabattus and Warren.

Fall armyworm:  Most sites had few or no fall armyworm moths in pheromone traps this week. The exception was Monmouth, where 5 moths were caught; exceeding the weekly threshold of three for silking corn. This is a late field with no silk yet. Single moths were caught in Biddeford, Dayton and Levant.  Very little fall armyworm feeding damage was found in younger corn fields.

Squash vine borer:  Moth counts were down significantly this week. Squash vine borers were caught in North Berwick, Wells, Dayton, Biddeford and Gray, but the threshold of five moths per week was not exceeded at any of these locations. This pest will likely only have one generation per year in Maine, although a late, partial second generation is possible.

Potato Leafhopper Alert:  Potato leafhopper feeding is showing up in vegetable and berry fields this week. Leafhoppers are small, bullet-shaped insects that feed on plant sap, causing the leaves to become curled, stunted and yellow-streaked. Beans are quite susceptible to the injury, in addition to potatoes and strawberries. The small, whitish leafhoppers adults can be seen flying off the plants when disturbed. The small, (1/16 inch) light green leafhopper nymphs are found on the underside of injured leaves.  Control options are listed in the New England Vegetable Management Guide.

Potato Leafhopper

Potato Leafhopper, photo by James Dill

Male and Female Spotted Wing Drosophila Flies

Male (left) and Female (right) Spotted Wing Drosophila, photo by Griffin Dill. Actual size: 2-3 mm.

Spotted Wing Drosophila Alert:  Captures of the fruit fly were fairly low this week, indicating that the population has not started its exponential growth yet. Flies were caught in Wells, New Gloucester, Dresden and Bowdoinham. The larvae of these flies can quickly destroy any soft fruit such as raspberries and blueberries. When spotted wing drosophila is found in your area, ripening fruit should be protected with a recommended insecticide. Regular and repeated treatments are usually needed to keep fruit from becoming infested. Visit our Spotted Wing Drosophila blog for more details.

Sincerely,

David T. Handley
Vegetable & Small Fruit Specialist

Highmoor Farm                       Pest Management Office
P.O. Box 179                             491 College Avenue
Monmouth, ME  04259        Orono, ME  04473
207.933.2100                          1.800.287.0279

Sweet Corn IPM Weekly Scouting Summary

Location CEW
Moths
ECB
Moths
FAW
Moths
%Feeding
Damage
Recommendations / Comments
Auburn 0 0 0 0% No spray recommended
Biddeford 1 1 1 14% One spray recommended for ECB + FAW feeding
Cape Elizabeth I 0 0 0 5% No spray recommended
Cape Elizabeth II 0 6 0 One spray recommended on silking corn for ECB
Charleston 7 17 0 3% 5-day spray interval recommended on all silking corn
Dayton I 3 3 0 0% 6-day spray interval recommended on all silking corn
Dayton II 4 1 1 2% 5-day spray interval recommended on all silking corn
Farmington 0 0 0 0% No spray recommended
Garland 3 3 0 1% 6-day spray interval recommended on all silking corn
Gray 0 4 0 0% No spray recommended
Levant 0 5 1 2% One spray recommended on silking corn for ECB
Lewiston 0 1 0 7% No spray recommended
Livermore Falls 0 0 0 No spray recommended
Monmouth 0 3 5 5% No spray recommended (no silking corn)
New Gloucester 1 12 0 0% One spray recommended on silking corn for ECB
No. Berwick 0 0 0 0% No spray recommended
Oxford 0 0 0 19% One spray recommended for ECB feeding
Palmyra 0 18 0 6% One spray recommended on silking corn for ECB
Sabattus 2 5 0 3% 6-day spray interval recommended on all silking corn
Wales 0 1 0 0% No spray recommended
Warren 2 1 0 7% 6-day spray interval recommended on all silking corn
Wells I 0 0 0 4% No spray recommended

CEW: Corn earworm (Only fresh silking corn should be sprayed for this insect.)
ECB:  European corn borer
FAW: Fall armyworm

Corn Earworm Spray Thresholds for Pheromone Traps

Moths caught per week Moths caught per night Spray interval
0.0 to 1.4 0.0 to 0.2 No spray
1.5 to 3.5 0.3 to 0.5 Spray every 6 days
3.6 to 7.0 0.6 to 1.0 Spray every 5 days
7.1 to 91 1.1 to 13.0 Spray every 4 days
More than 91 More than 13 Spray every 3 days

Thresholds apply only to corn with exposed fresh silk. Lengthen spray intervals by one day if maximum daily temperature is less than 80°F.

European Corn Borer Thresholds
Whorl stage: 30% or more of plants scouted show injury.
Pre-tassel-silk: 15% or more of plants scouted show injury.
Silk: 5 or more moths caught in pheromone traps in one week.

IPM Web Pages:
http://extension.umaine.edu/ipm/

http://www.pestwatch.psu.edu/sweet_corn.htm

http://www.umass.edu/umext/ipm/

Where brand names or company names are used it is for the reader’s information. No endorsement is implied nor is any discrimination intended against other products with similar ingredients. Always consult product labels for rates, application instructions and safety precautions. Users of these products assume all associated risks.

Published and distributed in furtherance of the Acts of Congress of May 8 and June 30, 1914, by the University of Maine Cooperative Extension, the Land Grant University of the State of Maine and the U.S. Department of Agriculture cooperating.  Cooperative Extension and other agencies of the U.S.D.A. provide equal opportunities in programs and employment.

Sweet Corn IPM Newsletter No. 5 – July 26, 2013

Friday, July 26th, 2013
Sweet Corn
Sweet Corn IPM Newsletter No. 5 – July 26, 2013
For full page print version, please see link at the bottom. Click on photos to enlarge.

CORN INSECT ACTIVITY REMAINS MODERATE

Squash Vine Borer and Spotted Wing Drosophila Pressure Increasing

SITUATION
Early corn harvest is coming into full swing in southern Maine. Maturity is variable, but overall quality looks good. The weather pattern has been limiting movement of moths into the region, so we have seen very little change in the populations of corn earworm and fall armyworm this week. A front moving in from the south this weekend may change the situation, but for now pest pressure remains moderate.

European Corn Borer on Ear of Corn

European Corn Borer on Ear, photo by David Handley

European corn borer: Moth catches in the southern parts of the state remain quite low this week. Two of the more northern sites had relatively high counts, however. Silking fields in Charleston and Palmyra were well over the threshold of 5 moths per week but the Charleston site is also on a spray schedule for corn earworm, so no additional sprays should be required. European corn borer feeding damage was over threshold in pre-tassel fields in Biddeford, Nobleboro and Warren this week.

Corn earworm:  Moths counts remain quite low in all locations this week and most locations did not require protection. A 4-day spray interval was recommended for Charleston and Garland. A 5-day spray interval was recommended for Levant. A 6-day spray interval was recommended for silking fields in Cape Elizabeth, Hollis and Farmington.

Fall armyworm:  Most sites had few or no fall armyworm moths in pheromone traps this week. The exceptions were Biddeford and New Gloucester, which both had 5 moths, exceeding the weekly threshold of three for silking corn. Neither site was under a spray interval for corn earworm so a spray was recommended for all silking corn. Single moths were caught in just three locations this week including Cape Elizabeth, Charleston and Oxford. Two moths were caught in Nobleboro. There is still relatively little fall armyworm feeding damage in younger corn fields.

Two Squash Vine Borer Moths

Two Squash Vine Borer Moths, photo by Jeffrey Hahn, Univ. of Minnesota

Squash vine borer moths were caught in pheromone traps in Wells, Hollis, Biddeford, Gray, New Gloucester, Nobleboro and Oxford this week. The threshold of five moths per week was exceeded in Biddeford, Hollis, Gray and New Gloucester. Be aware that this pest is very active and continues to threaten summer squash, winter squash and pumpkins. See the New England Vegetable Management Guide for control options.

Spotted Wing Drosophila Alert
Captures of spotted wing drosophila are rising this week. Flies were caught in Wells, New Gloucester, Monmouth, Dresden and Warren.  Numbers at the Warren site have increased significantly, with 84 flies caught this week. The larvae of these flies can quickly destroy any soft fruit such as raspberries and blueberries. If spotted wing drosophila has been captured in your area and you have ripening berries, the crop should be protected at this time with a recommended insecticide. Regular and repeated treatments are usually needed to keep fruit from becoming infested. Visit our Spotted Wing Drosophila blog for more details.

Highmoor Farm

FINAL REMINDER: Highmoor Farm Fruit and Vegetable Growers Field Day July 31, 2013
Join us for the Highmoor Farm Field Day and Summer Tour to be held on Wednesday, July 31, starting at 9:00 a.m. Please join us for the program, farm tours and lunch. Registration fee is $20 per person, including lunch, and preregistration is strongly encouraged. For more information, visit the Highmoor Farm website or call 207.933.2100. If you are a person with a disability and will need any accommodations to participate in this program, please call Pam St. Peter at Highmoor Farm, 207.933.2100 or TDD 1.800.287.8957 to discuss your needs at least 7 days prior to this event.

Sincerely,

David T. Handley
Vegetable & Small Fruit Specialist

Highmoor Farm                       Pest Management Office
P.O. Box 179                             491 College Avenue
Monmouth, ME  04259        Orono, ME  04473
207.933.2100                          1.800.287.0279

Sweet Corn IPM Weekly Scouting Summary

Location CEW
Moths
ECB
Moths
FAW
Moths
%Feeding
Damage
Recommendations / Comments
Auburn 2 7 0 0% 6-day spray interval recommended on all silking corn
Biddeford 1 0 5 35% One spray recommended on silking corn for FAW
Cape Elizabeth I 0 0 1 5% No spray recommended
Cape Elizabeth II 0 0 0 No spray recommended
Charleston 3 29 1 6% 6-day spray interval recommended on all silking corn
Dayton 0 0 0 7% No spray recommended
Farmington 2 0 0 4% 6-day spray interval recommended on all silking corn
Garland 0 5 0 1% One spray recommended on silking corn for ECB
Gray 0 5 0 7% One spray recommended on silking corn for ECB
Hollis 0 0 0 7% No spray recommended
Levant 0 5 0 3% One spray recommended on silking corn for ECB
Lewiston 2 0 0 5% 6-day spray interval recommended on all silking corn
Livermore Falls 0 0 0 13% No spray recommended
New Gloucester 0 0 5  7% One spray recommended on silking corn for FAW
Nobleboro 0 1 2 23% One spray recommended ECB feeding
No. Berwick 0 0 0 3% No spray recommended
Oxford 1 2 1 6% No spray recommended
Palmyra 0 15 0 1% One spray recommended on silking corn for ECB
Sabattus 3 2 0 5% 6-day spray interval recommended on all silking corn
Wales 3 1 0 6-day spray interval recommended on all silking corn
Warren 1 1 0 15% One spray recommended for ECB feeding
Wells I 0 0 0 5% No spray recommended
Wells II 1 0 0 2% No spray recommended

CEW: Corn earworm (Only fresh silking corn should be sprayed for this insect.)
ECB: European corn borer
FAW: Fall armyworm

Corn Earworm Spray Thresholds for Pheromone Traps

Moths caught per week Moths caught per night Spray interval
0.0 to 1.4 0.0 to 0.2 No spray
1.5 to 3.5 0.3 to 0.5 Spray every 6 days
3.6 to 7.0 0.6 to 1.0 Spray every 5 days
7.1 to 91 1.1 to 13.0 Spray every 4 days
More than 91 More than 13 Spray every 3 days

Thresholds apply only to corn with exposed fresh silk. Lengthen spray intervals by one day if maximum daily temperature is less than 80°F.

European Corn Borer Thresholds
Whorl stage:  30% or more of plants scouted show injury.
Pre-tassel-silk:  15% or more of plants scouted show injury.
Silk:  5 or more moths caught in pheromone traps in one week.

IPM Web Pages:
http://extension.umaine.edu/ipm/
http://www.pestwatch.psu.edu/sweet_corn.htm
http://www.umass.edu/umext/ipm/

Where brand names or company names are used it is for the reader’s information. No endorsement is implied nor is any discrimination intended against other products with similar ingredients. Always consult product labels for rates, application instructions and safety precautions. Users of these products assume all associated risks.

Published and distributed in furtherance of the Acts of Congress of May 8 and June 30, 1914, by the University of Maine Cooperative Extension, the Land Grant University of the State of Maine and the U.S. Department of Agriculture cooperating.  Cooperative Extension and other agencies of the U.S.D.A. provide equal opportunities in programs and employment.

Sweet Corn IPM Newsletter No. 4 – July 19, 2013

Friday, July 19th, 2013

Sweet Corn

Sweet Corn IPM Newsletter No. 4 – July 19, 2013

For full page print version, please see link at the bottom. Click on photos to enlarge.

INSECT ACTIVITY LOW TO MODERATE THIS WEEK

Stalled Weather Pattern Means Little Change to Pest Situation

SITUATION
Most fields did not see significant rain this week; in fact some southern and northern fields are starting to run dry. The heat has pushed corn development rapidly and a couple of early fields are just ready for harvest. Some later plantings look a bit spotty, with uneven development due to the extended cool, wet weather following planting. Generally, insect activity has been light to moderate this week, with several fields not requiring any additional protection. A predicted change in the weather pattern next week may bring about some changes in pest activity as well.

European corn borer:  Moth catches have declined to very low numbers this week, with most farms having no moths in the traps. A silking field in Charleston was the exception with 19 moths, exceeding the threshold of 5 moths per week in traps, but all of this sites are also on a spray schedule for corn earworm, so no additional sprays should be required. European corn borer feeding damage was over threshold in pre-tassel fields in North Berwick and Warren this week.

European Corn Borer Larva

European Corn Borer Larva, photo by David Handley

Corn Earworm Moth

Corn Earworm Moth, photo by David Handley

Corn earworm:  Moth counts were generally low in southern Maine this week and many locations did not require protection. In the more northern sites, counts were higher, and more frequent sprays were needed on silking corn. A 4-day spray interval was recommended for Charleston and Garland. A 5-day spray interval was recommended for Levant. A 6-day spray interval was recommended for silking fields in Cape Elizabeth, Hollis and Farmington.

Fall Armyworm Moths

Fall Armyworm Moths (female right, male left), photo by James Dill

Fall armyworm:  A slight increase in fall armyworm moth activity was seen this week.  Single moths were caught in seven locations this week including Auburn, Biddeford, Farmington, Dayton, Nobleboro, Oxford and Wells. At one field in New Gloucester, five moths were caught, exceeding the three-moth threshold for the week, so a spray for all silking corn was recommended. We have found very little fall armyworm feeding damage in younger corn fields, but we expect that levels will be increasing soon.

Squash vine borer moths were caught in pheromone traps in North Berwick, Wells, Hollis, Biddeford, Gray, and New Gloucester this week. The threshold of five moths per week was exceeded in North Berwick, Hollis, Gray and New Gloucester. Be aware that this pest is now active and threatens summer squash, winter squash and pumpkins.  See the New England Vegetable Management Guide for control options.

Highmoor Farm Highmoor Farm Fruit and Vegetable Growers Field Day July 31, 2013
Please join us for the Highmoor Farm Field Day and Summer Tour to be held on Wednesday, July 31, starting at 9:00 a.m. Growers will have an opportunity to tour the fruit and vegetable research plots at the farm, part of the Maine Agricultural and Forest Experiment Station, and hear Extension specialists and guest speakers discuss current research on apples, grapes and vegetables. Maine State Legislators will also be on hand to offer updates on programs and legislation effecting farming in Maine.  Please join us for the program, farm tours and lunch.

Registration fee is $20 per person, including lunch and preregistration is strongly encouraged. Visit the Field Day website for more information. If you are a person with a disability and will need any accommodations to participate in this program, please call Pam St. Peter at Highmoor Farm, 207.933.2100 or TDD 1.800.287.8957 to discuss your needs at least 7 days prior to this event.

Sincerely,

David T. Handley
Vegetable & Small Fruit Specialist

Highmoor Farm                       Pest Management Office
P.O. Box 179                             491 College Avenue
Monmouth, ME  04259        Orono, ME  04473
207.933.2100                          1.800.287.0279

Sweet Corn IPM Weekly Scouting Summary

Location CEW
Moths
ECB
Moths
FAW
Moths
%Feeding
Damage
Recommendations / Comments
Auburn 0 0 1 6% No spray recommended
Biddeford 1 0 1 14% No spray recommended
Cape Elizabeth I 1 0 0 7% No spray recommended
Cape Elizabeth II 2 0 0 6-day spray interval recommended on all silking corn
Charleston 9 19 0 2% 4-day spray interval recommended on all silking corn
Dayton 1 0 1 4% No spray recommended
Farmington 2 0 1 1% 6-day spray interval recommended on all silking corn
Garland 11 2 0 0% 4-day spray interval recommended on all silking corn
Gray 0 1 0 3% No spray recommended
Hollis 2 0 0 6-day spray interval recommended on all silking corn
Levant 5 0 0 1% 5-day spray interval recommended on all silking corn
Lewiston 0 0 0 0% No spray recommended
New Gloucester 0 0 5 One spray recommended on silking corn for FAW
Nobleboro 0 0 1 No spray recommended
No. Berwick 0 0 0 32% One spray recommended for ECB feeding
Oxford 0 0 1 4% No spray recommended
Palmyra 0 4 0 No spray recommended
Wales 0 1 0 6% No spray recommended
Warren 1 0 0 25% One spray recommended for ECB feeding
Wells I 0 0 0 2% No spray recommended
Wells II 0 1 1 6% No spray recommended

CEW: Corn earworm (Only fresh silking corn should be sprayed for this insect.)
ECB: European corn borer
FAW: Fall armyworm

Corn Earworm Spray Thresholds for Pheromone Traps

Moths caught per week Moths caught per night Spray interval
0.0 to 1.4 0.0 to 0.2 No spray
1.5 to 3.5 0.3 to 0.5 Spray every 6 days
3.6 to 7.0 0.6 to 1.0 Spray every 5 days
7.1 to 91 1.1 to 13.0 Spray every 4 days
More than 91 More than 13 Spray every 3 days

Thresholds apply only to corn with exposed fresh silk. Lengthen spray intervals by one day if maximum daily temperature is less than 80°F.

European Corn Borer Thresholds
Whorl stage: 30% or more of plants scouted show injury.
Pre-tassel-silk: 15% or more of plants scouted show injury.
Silk: 5 or more moths caught in pheromone traps in one week.

IPM Web Pages:
http://extension.umaine.edu/ipm/
http://www.pestwatch.psu.edu/sweet_corn.htm
http://www.umass.edu/umext/ipm/

Where brand names or company names are used it is for the reader’s information. No endorsement is implied nor is any discrimination intended against other products with similar ingredients. Always consult product labels for rates, application instructions and safety precautions. Users of these products assume all associated risks.

Published and distributed in furtherance of the Acts of Congress of May 8 and June 30, 1914, by the University of Maine Cooperative Extension, the Land Grant University of the State of Maine and the U.S. Department of Agriculture cooperating.  Cooperative Extension and other agencies of the U.S.D.A. provide equal opportunities in programs and employment.

Sweet Corn IPM Newsletter No. 3 – July 12, 2013

Friday, July 12th, 2013

Sweet Corn

Sweet Corn IPM Newsletter No. 3 – July 12, 2013

For full page print version, please see link at the bottom. Click on photos to enlarge.

EARLY SILKING CORN THREATENED BY CORN EARWORM

European Corn Borer also Active, Fall Armyworm Activity Low

SITUATION
Yet more rain in southern Maine
this week has kept fields wet and slowed growth, but more early planted fields are now coming into silk and first harvest is within sight. Insect activity has increased in most locations, and any silking corn is now threatened by both European corn borer and corn earworm.    

European Corn Borer Trap

European Corn Borer Trap, photo by David Handley

European Corn Borer Larvae on Pre-tassel Stage Corn

European Corn Borer Larvae on Pre-tassel Stage Corn, photo by David Handley

European corn borer:  Moth catches continue to be somewhat erratic this week, but most sites had relatively low counts. Silking fields in Gray, North Berwick and Sabattus were over the threshold of 5 moths per week in traps, but all of these sites are also on a spray schedule for corn earworm, so no additional sprays should be required.  European corn borer feeding damage was over threshold in pre-tassel fields in Biddeford, Cape Elizabeth, and Warren this week. We expect to see more late fields exceeding feeding injury in later plantings in the coming week.  Sprays applied at pre-tassel tend to be more effective than whorl or tassel stage sprays, because the larvae are usually more exposed.  

Corn Earworm Moth

Corn Earworm Moth, photo by David Handley

Corn earworm:  Moths are now being caught at most locations, but many fields do not yet have silking corn and so are not yet threatened by corn earworm. A 6-day spray interval was recommended for early silking fields in Dayton, Gray, No. Berwick, Oxford, Sabattus and Wells. A 5-day spray interval was recommended for silking fields in Farmington, Garland, and Nobleboro, where moth counts were slightly higher. A 4-day spray interval was recommended for one silking field in Cape Elizabeth where the highest moth count of the season was found this week.  

Fall armyworm:  Single moths were caught in two locations this week (Farmington, Lewiston). At this time fall armyworm is not a threat to silking corn. We have not found any fall armyworm feeding damage in younger corn fields, but we anticipate that it will be showing up soon.

Squash vine borer moths were caught in pheromone traps in North Berwick, Biddeford, Gray, New Gloucester and Nobleboro. The threshold of five moths per week was only exceeded in North Berwick, but growers should be aware that the pest is now active and threatens summer squash, winter squash and pumpkins. See the New England Vegetable Management Guide for control options.

Late Blight on Tomato Leaf

Late Blight on Tomato Leaf, photo by James Dill

Late Blight:  Grower and Farm Stand Alert
Late blight has been found on potato plants in northern Maine this week. This follows recent reports of late blight in tomato and potato plantings in New York and Massachusetts and many southern coastal states. Growers should be alert to catch early symptoms and be ready to apply appropriate control measures. Typical symptoms will be water-soaked lesions on the leaves with fine, white cottony mycelium on the undersides. Infections on the stems appear as dark, almost black lesions. Visit Cornell University Cooperative Extension’s web pages for photos of tomatoes and potatoes.  Please report any suspicious symptoms to the Pest Management Office 581.3883 (1.800.287.0279), or email PMO@umext.maine.edu.   

Reminder:  Highmoor Farm Field Day and Summer Tour will be held on Wednesday, July 31, 2013 from 9:00 a.m. to 4:00 p.m. Registration fee is $20 per person, including lunch, and preregistration is strongly encouraged. For more information, visit the Highmoor Farm website or call 207.933.2100. If you are a person with a disability and will need any accommodations to participate in this program, please call Pam St. Peter at Highmoor Farm, 207.933.2100 or TDD 1.800.287.8957 to discuss your needs at least 7 days prior to this event.

Sincerely,

David T. Handley
Vegetable & Small Fruit Specialist

Highmoor Farm                       Pest Management Office
P.O. Box 179                             491 College Avenue
Monmouth
, ME  04259        Orono, ME  04473
207.933.2100                          1.800.287.0279

Sweet Corn IPM Weekly Scouting Summary

Location CEW
Moths
ECB
Moths
FAW
Moths
%Feeding
Damage
Recommendations / Comments
Auburn 5 2 0 10% No spray recommended (no silking corn)
Biddeford 1 1 0 63% One spray recommended for ECB
Cape Elizabeth I 1 2 0 3% No spray recommended
Cape Elizabeth II 43 2 0 77% 4-day spray interval recommended on all silking corn
Charleston 14 8 0 7% No spray recommended (no silking corn)
Dayton 3 1 0 1% 6-day spray interval recommended on all silking corn
Farmington 4 1 1 5-day spray interval recommended on all silking corn
Dayton 0 0 0 0 No spray recommended
Garland 7 0 0 3% 5-day spray interval recommended on all silking corn
Gray 3 23 0 6-day spray interval recommended on all silking corn
Levant 4 2 0 0% No spray recommended (no silking corn)
Lewiston 0 0 1 2% No spray recommended
Livermore Falls 1 1 0 4% No spray recommended
New Gloucester 1 2 0 2% No spray recommended
Nobleboro 6 2 0 5-day spray interval recommended on all silking corn
No. Berwick 3 13 0 6-day spray interval recommended on all silking corn
Oxford 3 3 0 6-day spray interval recommended on all silking corn
Palmyra 0 8 0 2% No spray recommended
Sabattus 2 12 0 6-day spray interval recommended on all silking corn
Wales 0 0 0 0% No spray recommended
Warren 1 0 0 20% One spray recommended for ECB
Wells I 2 0 0 0% No spray recommended (no silking corn)
Wells II 3 4 0 4% 6-day spray interval recommended on all silking corn

CEW: Corn earworm (Only fresh silking corn should be sprayed for this insect.)
ECB: European corn borer
FAW: Fall armyworm

Corn Earworm Spray Thresholds for Pheromone Traps

Moths caught per week Moths caught per night Spray interval
0.0 to 1.4 0.0 to 0.2 No spray
1.5 to 3.5 0.3 to 0.5 Spray every 6 days
3.6 to 7.0 0.6 to 1.0 Spray every 5 days
7.1 to 91 1.1 to 13.0 Spray every 4 days
More than 91 More than 13 Spray every 3 days

Thresholds apply only to corn with exposed fresh silk. Lengthen spray intervals by one day if maximum daily temperature is less than 80°F.

European Corn Borer Thresholds
Whorl stage: 30% or more of plants scouted show injury.
Pre-tassel-silk: 15% or more of plants scouted show injury.
Silk: 5 or more moths caught in pheromone traps in one week.

IPM Web Pages:
http://extension.umaine.edu/ipm/
http://www.pestwatch.psu.edu/sweet_corn.htm
http://www.umass.edu/umext/ipm/

Where brand names or company names are used it is for the reader’s information. No endorsement is implied nor is any discrimination intended against other products with similar ingredients. Always consult product labels for rates, application instructions and safety precautions. Users of these products assume all associated risks.

Published and distributed in furtherance of the Acts of Congress of May 8 and June 30, 1914, by the University of Maine Cooperative Extension, the Land Grant University of the State of Maine and the U.S. Department of Agriculture cooperating.  Cooperative Extension and other agencies of the U.S.D.A. provide equal opportunities in programs and employment.

 

Sweet Corn IPM Newsletter No. 2 – July 8, 2013

Tuesday, July 9th, 2013

Sweet Corn

Sweet Corn IPM Newsletter No. 2 – July 8, 2013

For full page print version, please see link at the bottom. Click on photos to enlarge.

EUROPEAN CORN BORER, CORN EARWORM MOTHS ACTIVE

Silking Corn Needs Protection in Early Fields

SITUATION
Warm conditions and lots more rain have kept corn growing, but made it difficult to do any field work, such as spraying or side-dressing. Early fields in some areas are showing silk, and later fields, although uneven, are coming into pre-tassel. Some growers have had difficulty getting onto wet ground to seed their last plantings. The rain also is raising concerns about fertilizer and herbicide leaching.

European corn borer:  Moth catches were irregular this week with about half of the sites having any moths caught, and just a few over threshold for early fields with silking corn. Activity may increase over the next week, as the wet weather might extend the emergence of this first generation of moths. European corn borer feeding damage was over threshold in pre-tassel fields in Biddeford, Cape Elizabeth, Livermore Falls, and Nobleboro this week. One field (No. Berwick) that had both silking corn and was over threshold for moths was also put on a spray program for corn earworm, so no additional sprays were required.

European Corn Borer Damage

European Corn Borer Damage, photo by David Handley

Corn Earworm Moth

Corn Earworm Moth, photo by David Handley

Corn earworm:  About one half of the fields visited this week had corn earworm moths in pheromone traps. Most of these fields do not yet have any silking corn, so no sprays were recommended. When more than one corn earworm moth is found at a site, all silking corn in the fields should be protected with a spray. Additional sprays are based on the average number of moths caught per week or per night (see table below). Silking fields in Dayton, No. Berwick and Wells were recommended to go on a 6-day spray program for silking corn this week, based on a weekly capture of 3 moths.

Male Fall Armyworm Moth

Male Fall Armyworm Moth, photo by David Handley

Fall armyworm:  We have caught a couple of fall armyworm moths in pheromone traps this week, although the identification has not been confirmed. We have not yet seen any feeding damage from this pest, so no sprays for fall armyworm have been recommended.

Squash vine borer moths are being caught in pheromone traps in southern Maine. The moths lay their eggs at the base of squash or pumpkin plants, and the larvae tunnel into the vines, causing them to wilt and collapse. Entry holes can often be found near the base of the plant.  Sprays can be applied to control the moths and prevent egg-laying. Plow down squash plantings as soon as harvest is complete to prevent borers from overwintering in the field. There is one generation per year. See the New England Vegetable Management Guide for more details.

Japanese beetles are becoming plentiful in southern and mid-state areas. These insects often find their way into corn fields and may feed on the silks of developing ears, causing poor tip fill. Sprays for corn earworm (except Bt’s) will often control Japanese beetle as well.

Japanese Beetle

Japanese Beetle, photo by Edwin Remsberg, USDA

Male and Female Spotted Wing Drosophila Flies

Male (left) and Female (right) Spotted Wing Drosophila, photo by Griffin Dill. Actual size: 2-3 mm.

Spotted wing drosophila:  We have had our first captures of spotted wing drosophila in New Hampshire and Maine this week. These small fruit flies can cause serious fruit losses in raspberries, blueberries and other soft fruits. The flies will only attack fruit that has begun to ripen, and we don’t expect populations to reach damaging levels for a few weeks. For more information visit the Highmoor Farm website.

Sincerely,

David T. Handley
Vegetable & Small Fruit Specialist

Highmoor Farm                       Pest Management Office
P.O. Box 179                             491 College Avenue
Monmouth, ME  04259        Orono, ME  04473
207.933.2100                          1.800.287.0279

Sweet Corn IPM Weekly Scouting Summary

Location CEW
Moths
ECB
Moths
FAW
Moths
%Feeding
Damage
Recommendations / Comments
Auburn 0 7 0 8% No spray recommended (no silking corn)
Biddeford 0 2 0 42% One spray recommended for ECB on pre-tassel corn
Cape Elizabeth I 0 0 0 3% No spray recommended
Cape Elizabeth II 6 12 1 20% One spray recommended for ECB on pre-tassel corn
Dayton 3 1 1% 6-day spray interval recommended on all silking corn
Farmington 2 1 0 2% No spray recommended
Lewiston 0 0 0 0% No spray recommended
Livermore Falls 1 0 0 28% One spray recommended for ECB on pre-tassel corn
New Gloucester 0 0 1 0% No spray recommended
Nobleboro 2 11 0 18% No spray recommended (no silking corn)
No. Berwick 3 13 0 6-day spray interval recommended on all silking corn
Oxford 1 1 0 6% No spray recommended (no silking corn)
Warren 0 0 0 4% No spray recommended
Wells I 2 0 0 0% No spray recommended (no silking corn)
Wells II 3 4 0 4% 6-day spray interval recommended on all silking corn

CEW: Corn earworm (Only fresh silking corn should be sprayed for this insect.)
ECB: European corn borer
FAW: Fall armyworm

Corn Earworm Spray Thresholds for Pheromone Traps

Moths caught per week Moths caught per night Spray interval
0.0 to 1.4 0.0 to 0.2 No spray
1.5 to 3.5 0.3 to 0.5 Spray every 6 days
3.6 to 7.0 0.6 to 1.0 Spray every 5 days
7.1 to 91 1.1 to 13.0 Spray every 4 days
More than 91 More than 13 Spray every 3 days

Thresholds apply only to corn with exposed fresh silk. Lengthen spray intervals by one day if maximum daily temperature is less than 80°F.

European Corn Borer Thresholds
Whorl stage:  30% or more of plants scouted show injury.
Pre-tassel-silk:  15% or more of plants scouted show injury.
Silk:  5 or more moths caught in pheromone traps in one week.

IPM Web Pages:
http://extension.umaine.edu/ipm/
http://www.pestwatch.psu.edu/sweet_corn.htm
http://www.umass.edu/umext/ipm/

Where brand names or company names are used it is for the reader’s information. No endorsement is implied nor is any discrimination intended against other products with similar ingredients. Always consult product labels for rates, application instructions and safety precautions. Users of these products assume all associated risks.

Published and distributed in furtherance of the Acts of Congress of May 8 and June 30, 1914, by the University of Maine Cooperative Extension, the Land Grant University of the State of Maine and the U.S. Department of Agriculture cooperating.  Cooperative Extension and other agencies of the U.S.D.A. provide equal opportunities in programs and employment.

Sweet Corn IPM Newsletter No. 1 – June 27, 2013

Friday, June 28th, 2013

Sweet Corn

Sweet Corn IPM Newsletter No. 1 – June 27, 2013

For full page print version, please see link at the bottom. Click on photos to enlarge.

2013 SWEET CORN PEST SEASON BEGINS!

Corn Earworm, European Corn Borer Moths Active, Larvae Feeding in Early Corn

The 2013 University of Maine Cooperative Extension Integrated Pest Management (IPM) program for sweet corn is underway. More than twenty volunteer farms are serving as pest monitoring and demonstration sites, with fields in North Berwick, Wells, Dayton, Cape Elizabeth, New Gloucester, Poland Spring, Auburn, Lewiston, Sabattus, Nobleboro, Warren, Monmouth, Wales, Wayne, Oxford, Farmington, Levant, Stillwater, Garland and East Corinth. Pheromone traps have been set up at these farms to monitor the adult (moth) stages of European corn borer, corn earworm and fall armyworm, and we have begun scouting the fields for feeding injury by insect larvae. We will share the information we collected at these sites and management recommendations every week during the season through this newsletter and blog. If you would prefer to receive this newsletter via e-mail, give us a call at 207.933.2100 or send an e-mail message to: pamela.stpeter@.maine.edu.

David Handley Checking Harstack Trap for Corn Earworm Moth

Checking Harstack Trap for Corn Earworm Moth, photo by Edwin Remsberg, USDA

SITUATION
A spell of warm, dry conditions in late April and early May allowed farmers to begin planting corn early through plastic mulch or under row covers. Some of this corn is now in the tassel stage, with a few fields showing some early silk. However, the more recent cool, damp conditions have kept development of later plantings very slow, varying from just a few leaves to early whorl stage. Both European corn borer and corn earworm moths are active in some fields, but their impact is limited if corn is not yet silking.

European Corn Borer Moth

European Corn Borer Moth, photo by David Handley

European corn borer:  We are just starting to find European corn borer moths in the pheromone traps around the state, and activity will likely increase over the next two weeks. These moths are now laying eggs on the undersides of corn leaves. The egg masses are small and look like overlapping fish scales. European corn borer is the only one of the three major insect pests of corn that can successfully overwinter in Maine, and it is usually the first pest to become a significant problem. To monitor corn borer, we scout 100 corn plants in each field, examining twenty plants in a row at five different locations. This sample provides a good estimate of the total amount of injury in a field. In the early stages, European corn borer feeding damage looks like small “pinholes” in the leaves. Corn in the whorl stage only needs to be sprayed if fresh feeding injury is found on 30% or more of the plants scouted in a field. Once the corn reaches the pre-tassel stage, the control threshold is lowered to 15%. This is because larvae feeding on the later stages are more likely to move into the ears of the plant. On the tassels, feeding damage first appears as chewing and brown waste found in the small florets. After the tassel has emerged from the stalk, the larvae chew into the stalk just below it, often causing the tassel to fall over. Sprays during the pre-tassel stage, when both moths and larvae are present, reduce the opportunity for larvae to move into the stalks and ears of the plant. Once the larvae are in the stalks they are protected from sprays.

European Corn Borer Damage on Pre-tassel Stage corn

European Corn Borer Damage on Pre-tassel, photo by David Handley

Good spray coverage of the entire plant provides the most effective kill of larvae as they move from one part of the plant to another. Rotating the type of insecticide used also improves control. Materials registered for controlling European corn borer include Bacillus thuringiensis products (XenTari®, Dipel DF®), Avaunt®, Coragen®, Warrior®, Lannate®, Baythroid®, Asana®, Radiant®, Delta Gold®, Mustang®, Sevin XLR® and Larvin®. When corn reaches the silk stage, sprays may be based on the number of corn borer moths caught in pheromone traps rather than feeding injury. European corn borer moths will lay eggs on flag leaves of silking corn and the larvae can move into the ears without leaving visible feeding injury that would be noticed when scouting. Therefore, if more than five moths are caught during a week in a field with silking corn, a spray will be recommended. Varieties of corn genetically modified to produce the Bt toxin (e.g. Bt corn, Attribute® varieties), should not need to be sprayed to control European corn borer. European corn borer feeding damage has been increasing in recent days and fields in No. Berwick, Sabattus and Livermore Falls were over the damage threshold in pre-tassel fields. Expect more injury to be showing up as more eggs begin to hatch. Early silking fields in Nobleboro and Warren were over the threshold for European corn borer moths caught in pheromone traps and sprays for those fields were recommended.

Corn Earworm Moth

Corn Earworm Moth, photo by David Handley

Corn earworm:  Pheromone traps are now set up around the state to monitor the arrival of corn earworm. Corn earworm generally appears in Maine in early July, but the actual date varies greatly. The arrival of this pest is only a concern for fields with corn in the silk stage. Fields not yet in silk do not need to be protected from corn earworm. When corn earworm moths start being caught at a site, all silking corn in the fields should be protected with a spray. These moths lay eggs on the fresh silks and the larvae move directly into the ears of corn. When corn earworm moths cannot find silking corn to deposit their eggs on, they may lay eggs on the leaves of younger corn. The larvae will feed on the foliage and tassels, similar to armyworm, until the ears become available. When larvae are found feeding on younger corn, the damage is accounted for, along with any borer or armyworm damage, to determine if a spray is warranted. We have caught a few corn earworm moths in a few southern and coastal locations this week. Only two fields are showing silk now and single moth catches do not warrant a spray.

Fall Armyworm Moths

Fall Armyworm Moths (female right, male left), photo by James Dill

Fall armyworm:  This is usually the last serious corn insect pest to arrive in Maine. The moths must fly in from southern over-wintering sites, and tend to lay their eggs on the youngest corn available. When the larvae hatch, they chew large, ragged holes in the leaves, and may bore into developing ears. Larvae may also move into the ears through the silk channel, behaving similarly to corn earworm. Pheromone trap catches will indicate if there is a threat to silking corn. However, corn will usually be on a spray program for corn earworm when fall armyworm is present, and both insects would be controlled.

Common stalk borer:  This pest can be a problem early in the season, but usually only around the edges of fields. The injury is similar to European corn borer, but the feeding holes are larger, with four or five holes running across the width of a leaf. The larvae are purple colored with white stripes. If high numbers of stalk borer are found in pre-tassel stage corn within the field (not just along the edges), include the injury with corn borer to determine if control is needed. Injury found in whorl stage corn is not a concern because the larvae will leave the plant before ears emerge.

Common Stalk Borer Damage

Common Stalk Borer Damage, photo by David Handley

Do-It-Yourself IPM:  To get the most accurate information about the pest situation on your farm you should monitor the fields yourself on a regular basis. Pheromone traps and lures are available that can give you an accurate, early warning of the arrival of all of the major insect pests. Traps and lures can be purchased from pest management supply companies such as Gempler’s (1.800.382.8473) or Great Lakes IPM (517.268.5693).

To learn more about IPM scouting techniques, insect identification and control thresholds, order the fact sheet Managing Insect Pests of Sweet Corn available from the University of Maine Cooperative Extension. Color pictures are provided to help with insect identification, and a chart with spray thresholds is supplied to post near your sprayer for easy reference. You can download a copy from the Pest Management website or call the Pest Management Office at 1.800.287.0279.

High Tunnel Tomatoes

High Tunnel Tomatoes, photo by Danielle Murray

Hold the Date!
Highmoor Farm Field Day and Summer Tour is on Wednesday, July 31, 2013 from 9:00 a.m. to 3:00 p.m. Registration fee is $20.00, including lunch, and preregistration is strongly encouraged. For more information, visit the Highmoor Farm website. Please contact Pam St. Peter at pamela.stpeter@maine.edu or 207.933.2100 to preregister.

Sincerely,

David T. Handley
Vegetable & Small Fruit Specialist

Highmoor Farm                       Pest Management Office
P.O. Box 179                             491 College Avenue
Monmouth, ME  04259        Orono, ME  04473
207.933.2100                          1.800.287.0279

Sweet Corn IPM Weekly Scouting Summary

Location CEW
Moths
ECB
Moths
FAW
Moths
%Feeding
Damage
Recommendations / Comments
Auburn 1 25 No spray recommended (no silking corn)
Biddeford 0 5 0 10% No spray recommended (no silking corn)
Cape Elizabeth I 0 2 0 No spray recommended
Cape Elizabeth II 3 20 0 No spray recommended (no silking corn)
Dayton 1 0 0 0% No spray recommended (no silking corn)
Farmington 0 0 0 0% No spray recommended
Lewiston 0 0 0 0% No spray recommended
Livermore Falls 1 0 0 18% One spray recommended for ECB on pre-tassel corn
New Gloucester 0 1 0 0% No spray recommended
Nobleboro 0 26 0 2% One spray recommended for ECB on silking corn
No. Berwick 0 20 0 34% One spray recommended for ECB on pre-tassel corn
Oxford 0 4 0 No spray recommended (no silking corn)
Sabattus 0 33 0 19% One spray recommended for ECB on pre-tassel corn
Wales 0 0 0 0% No spray recommended
Warren 1 7 0 5% One spray recommended for ECB on silking corn
Wells I 0 2 0 0% No spray recommended
Wells II 0 0 0 0% No spray recommended

CEW: Corn earworm (Only fresh silking corn should be sprayed for this insect.)
ECB:  European corn borer
FAW: Fall armyworm

 

Corn Earworm Spray Thresholds for Pheromone Traps

Moths caught per week Moths caught per night Spray interval
0.0 to 1.4 0.0 to 0.2 No spray
1.5 to 3.5 0.3 to 0.5 Spray every 6 days
3.6 to 7.0 0.6 to 1.0 Spray every 5 days
7.1 to 91 1.1 to 13.0 Spray every 4 days
More than 91 More than 13 Spray every 3 days

Thresholds apply only to corn with exposed fresh silk. Lengthen spray intervals by one day if maximum daily temperature is less than 80°F.

European Corn Borer Thresholds
Whorl stage: 30% or more of plants scouted show injury.
Pre-tassel-silk: 15% or more of plants scouted show injury.
Silk: 5 or more moths caught in pheromone traps in one week.

IPM Web Pages:
http://extension.umaine.edu/ipm/
http://www.pestwatch.psu.edu/sweet_corn.htm
http://www.umass.edu/umext/ipm/

Where brand names or company names are used it is for the reader’s information.  No endorsement is implied nor is any discrimination intended against other products with similar ingredients.  Always consult product labels for rates, application instructions and safety precautions.  Users of these products assume all associated risks.

Published and distributed in furtherance of the Acts of Congress of May 8 and June 30, 1914, by the University of Maine Cooperative Extension, the Land Grant University of the State of Maine and the U.S. Department of Agriculture cooperating.  Cooperative Extension and other agencies of the U.S.D.A. provide equal opportunities in programs and employment.

Sweet Corn IPM Newsletter No. 14 – September 17, 2012

Monday, September 17th, 2012

Sweet Corn

For full page print version, please see link at the bottom.  Click on photos to enlarge.

Last Issue for 2012

ANY FRESH SILKING CORN REMAINING NEEDS PROTECTION

Corn Earworm Still a Threat to Late Corn

This will be the final issue of the Sweet Corn IPM Newsletter for the 2012 season.  I would like to thank all of the growers who participated in the program this year, and our team of IPM scouts including John Banville, Tammy Cushman, Chase Gaewski, Griffin Dill and Sean McAuley, with help from John Hutton and Kara Rowley.  Special thanks go to Katie Woodman who coordinated the team.

SITUATION
Hurricane Isaac appears to have only caused a mild bump in pest numbers over the past week, and it is likely that cooler temperatures will slow pest activity in the coming days.  Any silking corn remaining requires protection from corn earworm statewide, but fall armyworm and European corn borer are only at problem levels in a few sites.

European corn borer:  Moth counts continued to be very low last week in most locations.  Although fields in Oxford and Wayne exceeded the 5-moth threshold for silking corn, which suggests the start of a second generation.  Both sites are on spray schedules for corn earworm, so no additional sprays were needed.  Feeding damage was found in a pre-silking field in Biddeford, and exceeded the 15% threshold when combined with fall armyworm damage.

European Corn Borer Larva on Ear

European Corn Borer Larva on Ear, photo by David Handley

Corn earworm:  Moth counts were generally higher last week, returning many fields to tighter spray intervals on fresh silking corn.  A 4-day spray interval for silking corn was recommended for Cape Elizabeth, Dayton, Levant, New Gloucester, Nobleboro, North Berwick, Wales,Wayne and Warren.  A 5-day spray interval was recommended for Biddeford, Dresden, Lewiston, and one Wells location.  A 6-day spray interval was recommended for Jefferson, Oxford, Poland Spring and Wells.

Corn Earworm

Corn Earworm, photo by David Handley

Fall armyworm:  Most fields are under spray schedules for corn earworm, so little feeding damage is being noted.  Only one Biddeford field was over the threshold when combined with ECB feeding damage.  Moth captures remained low, with only one field in Levant exceeding the spray threshold of 3 moths in silking corn.  Single moths were caught in Lewiston, Monmouth and New Gloucester.

Adult Fall Armyworm

Adult Fall Armyworm, photo by David Handley

It’s time for cover crops!
Plowing down corn stalks destroys the over wintering sites of European corn borer, but late plowing can leave soil prone to erosion during the winter and spring.  Planting winter rye is a good option for many fields.  It can be planted well into September to produce enough of a cover to prevent erosion. Rye will survive the winter and put on more growth in the spring.  It should be killed by plowing, mowing or herbicide before it goes to seed.  Having rye on the field may delay planting in the spring, as you must wait for conditions to be warm and dry enough to plow it in.  Animal manures can also be applied to soils in early fall and incorporated to improve soil structure and provide nutrients.  Cover crops should be seeded after manure applications to absorb and hold nutrients, which will be released after the crop is plowed down the following spring.

Sincerely,

David T. Handley
Vegetable & Small Fruit Specialist

Highmoor Farm                      Pest Management Office
P.O. Box179                          491 College Ave
Monmouth,ME 04259            Orono,ME 04473
207.933.2100                       1.800.287.0279

Sweet Corn IPM Weekly Scouting Summary

Location CEW
Moths
ECB
Moths
FAW
Moths
%Feeding
Damage
Recommendations / Comments
Biddeford 5 0 0 24% 5-day spray interval for all silking corn
Cape Elizabeth I 9 0 0 All Silk 4-day spray interval for all silking corn
Cape Elizabeth II 18 0 0 All Silk 4-day spray interval for all silking corn
Dayton I 8 0 0 All Silk 4-day spray interval for all silking corn
Dresden 4 0 0 All Silk 5-day spray interval for all silking corn
Jefferson 2 0 0 All Silk 6-day spray interval for all silking corn
Levant 15 0 3 All Silk 4-day spray interval for all silking corn
Lewiston 6 0 1 All Silk 5-day spray interval for all silking corn
Monmouth 0 0 1 All Silk No spray recommended
New Gloucester 38 0 1 All Silk 4-day spray interval for all silking corn
Nobleboro 33 0 0 All Silk 4-day spray interval for all silking corn
North Berwick 17 0 0 All Silk 4-day spray interval for all silking corn
Oxford 3 13 0 All Silk 6-day spray interval for all silking corn
Poland Spring 2 1 0 All Silk 6-day spray interval for all silking corn
Wales 23 1 0 All Silk 4-day spray interval for all silking corn
Wayne 11 10 0 All Silk 4-day spray interval for all silking corn
Warren 9 0 0 All Silk 4-day spray interval for all silking corn
Wells I 3 0 0 All Silk 6-day spray interval for all silking corn
Wells II 5 0 0 All Silk 5-day spray interval for all silking corn

CEW:  Corn earworm (Only fresh silking corn should be sprayed for this insect.)
ECB:   European corn borer
FAW:  Fall armyworm

Corn Earworm Spray Thresholds for Pheromone Traps

Moths caught per week Moths caught per night Spray interval
0.0 to 1.4 0.0 to 0.2 No spray
1.5 to 3.5 0.3 to 0.5 Spray every 6 days
3.6 to 7.0 0.6 to 1.0 Spray every 5 days
7.1 to 91 1.1 to 13.0 Spray every 4 days
More than 91 More than 13 Spray every 3 days

Thresholds apply only to corn with exposed fresh silk. Lengthen spray intervals by one day if maximum daily temperature is less than 80°F.

European Corn Borer Thresholds
Whorl stage: 30% or more of plants scouted show injury.
Pre-tassel-silk: 15% or more of plants scouted show injury.
Silk: 5 or more moths caught in pheromone traps in one week.

IPM Web Pages:
http://extension.umaine.edu/ipm/
http://www.pestwatch.psu.edu/sweet_corn.htm
http://www.umass.edu/umext/ipm/

Where brand names or company names are used it is for the reader’s information.  No endorsement is implied nor is any discrimination intended against other products with similar ingredients.  Always consult product labels for rates, application instructions and safety precautions.  Users of these products assume all associated risks.

Published and distributed in furtherance of the Acts of Congress of May 8 and June 30, 1914, by the University of Maine Cooperative Extension, the Land Grant University of the State of Maine and the U.S. Department of Agriculture cooperating.  Cooperative Extension and other agencies of the U.S.D.A. provide equal opportunities in programs and employment.

Sweet Corn IPM Newsletter No. 13 – September 5, 2012

Wednesday, September 5th, 2012

Sweet Corn

For full page print version, please see link at the bottom.  Click on photos to enlarge.

CORN EARWORM REMAINS LOW…  FOR NOW…

Fall Armyworm and European Corn Borer also Remain Scarce

SITUATION
This is a somewhat abbreviated issue, due to the Labor Day holiday and a much reduced scouting team this week.  In addition, it does not include the potential impact of the remains of hurricane Isaac, which are passing over Maine today.  Although insect counts have been very low for this time of year, the passing of a tropical storm can bring with it a significant population of corn pests, especially corn earworm and fall armyworm, so we should anticipate higher pressure by the end of the week for any fresh silking corn remaining in the field.

European corn borer:  Moth counts are very low this week with only one site in Cape Elizabeth exceeding the 5-moth threshold for silking corn, but the site is also on a spray schedule for corn earworm, so no additional sprays are needed.  Feeding damage was also low.  Only a North Berwick field exceeded the 15% threshold when combined with fall armyworm damage.

Corn earworm:  Moth counts were at low to moderate levels this week, although we anticipate increased activity due to the tropical storm remnants passing through Maine today.  A 4-day spray interval for fresh silking corn was recommended for one Dayton location and Nobleboro.  A 5-day spray interval was recommended for Cape Elizabeth, Dayton, New Gloucester, North Berwick,Wayne and Warren.  A 6-day spray interval was recommended for Biddeford, Charleston, Jefferson, Monmouth, Wales and Wells.

Corn Earworm Moth

Corn Earworm Moth, photo by David Handley

Fall armyworm:  Most fields are now in silk and under spray schedules for corn earworm, so very little feeding damage is being noted.  Only one North Berwick field was over the threshold when combined with ECB feeding damage.  Moth captures remain low for this time of year, with no sites exceeding the spray threshold of 3 moths in silking corn.  Single moths were caught in Biddeford, Cape Elizabeth, Monmouth, New Gloucester, and Warren.

Male Fall Armyworm Moth

Male Fall Armyworm Moth, photo by David Handley

The Food Safety Modernization Act (FSMA) and Its Possible Effects on Maine’s Specialty Crop Growers
AgMatters LLC cordially invites you to attend a workshop about this important new legislation.  Joy Johanson from the Produce Safety staff with the FDA will give an overview of FSMA and the Produce Safety Rule.  Representatives from the Maine Board of Pesticides Control will address Worker Protection Training and a new law requiring Pesticide Licensing of all growers.  Lauchlin and Linda Titus from AgMatters LLC will share their impressions on the future of Maine’s Specialty Crop Markets and suggestions on how growers can capitalize on changes in the industry.  Please register for one of the following times and locations:

Tuesday, September 11, 2012
10:00 AM to 2:00 PM
Bangor Motor Inn, 701 Hogan Rd., Bangor (Exit 187 off Interstate 95)
Tel. 207.947.0355

Or

Wednesday, September 12, 2012
10:00 AM to 2:00 PM
Ramada Inn, 490 Pleasant St., Lewiston (Exit 80 off Interstate 95)
Tel. 207.784.2331

Please RSVP as soon as possible by phone 873.2108 or by email to ltitus21@myfairpoint.net.

Sincerely,

David T. Handley
Vegetable & Small Fruit Specialist

Highmoor Farm                      Pest Management Office
P.O. Box179                          491 College Ave
Monmouth,ME 04259            Orono,ME 04473
207.933.2100                       1.800.287.0279

Sweet Corn IPM Weekly Scouting Summary

Location CEW Moths ECB Moths FAW Moths %Feeding Damage Recommendations / Comments
Biddeford 2 0 1 8% 6-day spray interval for all silking corn
Cape Elizabeth I 5 5 0 All silking 5-day spray interval for all silking corn
Cape Elizabeth II 5 1 1 4% 5-day spray interval for all silking corn
Charleston 3 2 0 All silking 6-day spray interval for all silking corn
Dayton I 15 0 0 All silking 4-day spray interval for all silking corn
Dayton II 6 0 0 All silking 5-day spray interval for all silking corn
Jefferson 3 0 0 All silking 6-day spray interval for all silking corn
Monmouth 2 1 1 All silking 6-day spray interval for all silking corn
New Gloucester 5 0 1 All silking 5-day spray interval for all silking corn
Nobleboro 14 1 0 All silking 4-day spray interval for all silking corn
No. Berwick 7 0 0 All silking 5-day spray interval for all silking corn
Sabattus 0 0 0 All silking No spray recommended
Wales 2 0 0 All silking 6-day spray interval for all silking corn
Warren 5 2 1 All silking 5-day spray interval for all silking corn
Wayne 4 0 0 All silking 5-day spray interval for all silking corn
Wells I 2 0 0 All silking 6-day spray interval for all silking corn
Wells II 3 0 0 All silking 6-day spray interval for all silking corn

CEW: Corn earworm (Only fresh silking corn should be sprayed for this insect.)
ECB:  European corn borer
FAW: Fall armyworm

Corn Earworm Spray Thresholds for Pheromone Traps

Moths caught per week Moths caught per night Spray interval
0.0 to 1.4 0.0 to 0.2 No spray
1.5 to 3.5 0.3 to 0.5 Spray every 6 days
3.6 to 7.0 0.6 to 1.0 Spray every 5 days
7.1 to 91 1.1 to 13.0 Spray every 4 days
More than 91 More than 13 Spray every 3 days

Thresholds apply only to corn with exposed fresh silk.  Lengthen spray intervals by one day if maximum daily temperature is less than 80°F.

European Corn Borer Thresholds
Whorl stage:  30% or more of plants scouted show injury.
Pre-tassel-silk:  15% or more of plants scouted show injury.
Silk:  5 or more moths caught in pheromone traps in one week.

IPM Web Pages:
http://extension.umaine.edu/ipm/
http://www.pestwatch.psu.edu/sweet_corn.htm
http://www.umass.edu/umext/ipm/

Where brand names or company names are used it is for the reader’s information.  No endorsement is implied nor is any discrimination intended against other products with similar ingredients.  Always consult product labels for rates, application instructions and safety precautions.  Users of these products assume all associated risks.

Published and distributed in furtherance of the Acts of Congress of May 8 and June 30, 1914, by the University of Maine Cooperative Extension, the Land Grant University of the State of Maine and the U.S. Department of Agriculture cooperating.  Cooperative Extension and other agencies of the U.S.D.A. provide equal opportunities in programs and employment.

Sweet Corn IPM Newsletter No. 12 – August 29, 2012

Wednesday, August 29th, 2012

Sweet Corn

For full page print version, please see link at the bottom.  Click on photos to enlarge.

CORN EARWORM PRESSURE LOWER UNDER COOL NIGHTS

Fall Armyworm and European Corn Borer Numbers Remain Low

SITUATION
Recent relatively cool nights indicate a shift in the weather pattern and have resulted in a dramatic drop in corn earworm captures this week.  However, populations are still high enough to keep all silking fields on a regular spray schedule.  As we approach Labor Day and the season starts to wind down, we have very little pressure from either fall armyworm or European corn borer.  Hot weather predicted for the remainder of the week will push remaining corn maturity along rapidly.  Remnants of hurricane Isaac may visit Maine next week and could bring with it a new flush of earworm and armyworm.

European corn borer:  Moth counts are very low this week with no sites exceeding the 5-moth threshold for silking corn.  Feeding damage was also low, with only the North Berwick site exceeding the 15% threshold when it was combined with fall armyworm damage.

Corn earworm:  Moth counts were significantly lower in all locations this week, but pressure still remains moderate to high for many locations.  A 3-day spray interval for fresh silking corn was recommended only for North Berwick.  A 4-day spray interval was recommended for Biddeford, one Cape Elizabeth location, Dayton, Dresden, East Corinth, Levant, Lewiston, Monmouth, Wales, Wayne and one Wells location.  A 5-day spray interval was recommended for one Cape Elizabeth location, New Gloucester, Nobleboro, Oxford, and one Wells location.  A 6-day spray interval was recommended for Charleston, Jefferson, Palmyra, Poland Spring, and Warren.

Corn Earworm Larvae

Corn Earworm Larvae, photo by David Handley

Fall armyworm:  We continue to find light feeding damage in some fields, but only North Berwick was over the threshold when combined with ECB feeding damage.  Moth captures continue to be very low for this time of year, with no sites exceeding the spray threshold of 3 moths in silking corn.  Two fall armyworm moths were caught at Cape Elizabeth, and one Lewiston location, and single moths were caught in Biddeford, Cape Elizabeth, Dresden, East Corinth, New Gloucester, and Warren.  Fall armyworm feeding damage was found in Biddeford, Cape Elizabeth and New Gloucester, but was below the 15% threshold.  Most remaining fields are silking and under a spray schedule for corn earworm, so field scouting is not necessary.

Fall Armyworm on Corn Silk

Fall Armyworm on Corn Silk, photo by David Handley

Spotted Wing Drosophila Update:
Over the last week spotted wing drosophila numbers have risen significantly. Flies are now at their highest levels of the season.  We have also found drosophila maggots infesting blueberry, raspberry, blackberry, elderberry, grape and peach fruit this week.  For those with late fruit crops still to harvest, protection is necessary to prevent infestation by spotted wing drosophila.  Up to this point weekly applications of an allowed insecticide have been adequate, but reports from the field suggest that more frequent applications may be necessary to keep fruit free from maggots.  Growers in southern states have found that a 3 to 5-day spray schedule was needed to prevent infestation.

Spotted Wing Drosophila Larva in Blueberry

Spotted Wing Drosophila Larvae in Blueberry, photo by David Handley

 

Spotted Wing Drosophila Larvae in Raspberry

Spotted Wing Drosophila Larvae in Raspberry, photo by David Handley

Sincerely,

David T. Handley
Vegetable & Small Fruit Specialist

Highmoor Farm                      Pest Management Office
P.O. Box179                          491 College Ave
Monmouth,ME 04259            Orono,ME 04473
207.933.2100                        1.800.287.0279

Sweet Corn IPM Weekly Scouting Summary

Location CEW
Moths
ECB
Moths
FAW
Moths
%Feeding Damage Recommendations / Comments
Biddeford 8 1 1 6% 4-day spray interval for all silking corn
Cape Elizabeth I 9 0 2 All silking 4-day spray interval for all silking corn
Cape Elizabeth II 7 0 1 5% 5-day spray interval for all silking corn
Charleston 2 1 0 1% 6-day spray interval for all silking corn
Dayton I 33 0 0 All silking 4-day spray interval for all silking corn
Dayton II 15 0 0 All silking 4-day spray interval for all silking corn
Dresden 32 0 1 All silking 4-day spray interval for all silking corn
East Corinth 16 0 1 0% 4-day spray interval for all silking corn
Jefferson 3 0 0 All silking 6-day spray interval for all silking corn
Levant 11 0 0 2% 4-day spray interval for all silking corn
Lewiston I 47 0 2 All silking 4-day spray interval for all silking corn
Lewiston II 11 1 0 0% 4-day spray interval for all silking corn
Monmouth 40 0 0 All silking 4-day spray interval for all silking corn
New Gloucester 5 0 1 2% 5-day spray interval for all silking corn
Nobleboro 5 0 0 All silking 5-day spray interval for all silking corn
No. Berwick 129 0 0 18% 3-day spray interval for all silking corn
Oxford 5 0 0 All silking 5-day spray interval for all silking corn
Palmyra 2 0 0 All silking 6-day spray interval for all silking corn
Poland Spring 2 0 0 All silking 6-day spray interval for all silking corn
Wales 20 0 0 All silking 4-day spray interval for all silking corn
Warren 2 0 1 All silking 6-day spray interval for all silking corn
Wayne 18 0 0 All silking 4-day spray interval for all silking corn
Wells I 9 0 0 All silking 4-day spray interval for all silking corn
Wells II 6 1 0 All silking 5-day spray interval for all silking corn

CEW: Corn earworm (Only fresh silking corn should be sprayed for this insect.)
ECB:  European corn borer
FAW: Fall armyworm

 

Corn Earworm Spray Thresholds for Pheromone Traps

Moths caught per week Moths caught per night Spray interval
0.0 to 1.4 0.0 to 0.2 No spray
1.5 to 3.5 0.3 to 0.5 Spray every 6 days
3.6 to 7.0 0.6 to 1.0 Spray every 5 days
7.1 to 91 1.1 to 13.0 Spray every 4 days
More than 91 More than 13 Spray every 3 days

Thresholds apply only to corn with exposed fresh silk. Lengthen spray intervals by one day if maximum daily temperature is less than 80°F.

European Corn Borer Thresholds
Whorl stage:  30% or more of plants scouted show injury.
Pre-tassel-silk:  15% or more of plants scouted show injury.
Silk:  5 or more moths caught in pheromone traps in one week.

IPM Web Pages:
http://extension.umaine.edu/ipm/
http://www.pestwatch.psu.edu/sweet_corn.htm
http://www.umass.edu/umext/ipm/

Where brand names or company names are used it is for the reader’s information.  No endorsement is implied nor is any discrimination intended against other products with similar ingredients.  Always consult product labels for rates, application instructions and safety precautions.  Users of these products assume all associated risks.

Published and distributed in furtherance of the Acts of Congress of May 8 and June 30, 1914, by the University of Maine Cooperative Extension, the Land Grant University of the State of Maine and the U.S. Department of Agriculture cooperating.  Cooperative Extension and other agencies of the U.S.D.A. provide equal opportunities in programs and employment.