Sweet Corn IPM Newsletter No. 1 – June 23, 2017

June 23rd, 2017 12:35 PM

Sweet CornSweet Corn IPM Newsletter No. 1 – June 23, 2017
Click on photos to enlarge.

2017 SWEET CORN PEST SEASON BEGINS!

European Corn Borer Active in Early Fields

The 2017 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. We have set up pheromone traps at these locations to monitor the adult (moth) stages of European corn borer, corn earworm and fall armyworm, and we are scouting the fields for feeding injury by insect larvae. We will share the information we collect along with management recommendations through this newsletter blog. It will also be posted on the Highmoor Farm web page blog: (http://extension.umaine.edu/highmoor/news-events/). 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.

SITUATION
A cool, wet start to the season has delayed both the planting and emergence of sweet corn. Early plantings in southern Maine and plots started under plastic or row covers are mostly at late whorl or pre-tassel. Late fields are just starting to emerge. Early scouting has not shown any significant insect problems at this time, although we expect European corn borer to become active soon.

European corn borer:  Pheromone traps for moths are set up in the grassy borders around cornfields. We have begun scouting late whorl and pre-tassel fields in southern Maine, but have not yet found any larvae feeding on the leaves or emerging tassels. In the early stages, European corn borer larvae are very small and translucent with shiny black heads. They emerge from small egg masses that look like a tiny clump of overlapping fish scales on the undersides of corn leaves. European corn borer overwinters in Maine, and 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 provides a good estimate of the total amount of injury in a field.

European Corn Borer Moth

European Corn Borer Moth, photo by David Handley

European Corn Borer Damage

European Corn Borer Damage, photo by David Handley

In the early stages, European corn borer feeding damage looks like small “pinholes” in the leaves. Whorl stage corn 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% because larvae feeding on the later stages are more likely to move into the ears. On the tassels, feeding damage first appears as chewing and brown waste found in the small florets. After the tassel has emerged from the whorl, 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, target the larvae before can they move into the protection of the stalks and ears. 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®.

Growers should start scouting whorl stage corn for feeding injury now. Once 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. If more than five moths are caught during a week in a field with silking corn, a spray is 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.

Corn Earworm Moth

Corn Earworm Moth, photo by David Handley

Corn earworm:  We have set up pheromone traps around the state for corn earworm moths. 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 are 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 or tassels 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.

 

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. Last year, fall armyworm moths arrived in Maine relatively early in the season, and were often more of a threat than corn earworm. This was an unusual situation for Maine and we will be watching fall armyworm closely this year to see if this is a new, unfortunate trend.

Common armyworm:  There have been reports of serious infestations of common armyworm in silage corn, alfalfa and hayfields this spring. Common armyworm can become active as early as April in Maine and can become a problem in early planted sweet corn. However, if the corn is established, it will outgrow the injury, as the caterpillars usually pupate before the ears develop. However, when heavy infestations occur, control may be required.  Common armyworm larvae are brown with yellow and black stripes running along the body. They chew large, ragged holes in the leaves, similar to fall armyworm.

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).

European Corn Borer Trap

European Corn Borer Trap, photo by David Handley

Harstack Trap

Harstack Trap, photo by David Handley

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 our website at http://umaine.edu/ipm/ipddl/publications/5101e/ or call the Pest Management Office at 1.800.287.0279.

Sincerely,

David T. Handley
Vegetable and 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

IPM Web Pages:
http://extension.umaine.edu/ipm/
http://www.pestwatch.psu.edu/sweet_corn.htm
http://ag.umass.edu/integrated-pest-management/umass-extension-programs

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

The University of Maine is an equal opportunity/affirmative action institution.

 

Highmoor Farm Field Day – July 26, 2017

June 20th, 2017 11:16 AM

University of Maine Cooperative Extension Highmoor FarmHighmoor Farm Field Day

Wednesday, July 26, 2017
8:30 AM to 3:00 PM
Highmoor Farm, 52 US Route 202, Monmouth, Maine 04259
Registration fee is $25.00 (includes lunch). Preregistration is strongly encouraged.

Register online here. Contact Pam St. Peter at pamela.stpeter@maine.edu or 207.933.2100 for registration information. Please register by July 17 to give us an accurate count for lunch.

The Maine State Pomological Society and Maine Vegetable and Small Fruit Growers Association will be joining with the Maine Agricultural and Forest Experiment Station and the University of Maine Cooperative Extension to hold a public field day at Highmoor Farm in Monmouth on Wednesday, July 26, 2017, rain or shine.

This year’s field day will include tours of current research projects in tree fruit, and projects in vegetables, pumpkin trials, broccoli evaluations, as well as reduced tillage in organic systems and permanent beds, high tunnel tomatoes, and irrigation and compost application in high tunnels.

Special guest speaker will be Dr. Gennaro Fazio, apple rootstock expert at the USDA-ARS Plant Genetic Resources Unit and Adjunct Associate Professor at Cornell University in New York.

Growers are welcome to attend the whole day, or may come for just the morning or afternoon programs and tours. Whichever you decide, please plan to be there for lunch to share some time and informal discussion with fellow farmers, research and Extension staff and state officials.

Highmoor Farm is the Field Research Station for fruits and vegetables, and has been working with Maine farmers to improve crop production since 1909, when the farm was purchased by the state to carry out research on orchard practices. For more than 100 years, researchers at Highmoor Farm have helped to develop cultural techniques, new varieties and pest management practices to improve the success of Maine’s vegetable and fruit farmers.

AGENDA

8:30 AM Registration – coffee and donuts courtesy of Crop Protection Services
9:30 AM Welcome and Opening Remarks
Fred Servello, Maine Agricultural & Forest Experiment Station
John Rebar, University of Maine Cooperative Extension DirectorErin Roche, University of Maine Crop Insurance Education Program
9:15 AM Food Safety Modernization Act Update
David Handley, University of Maine Cooperative Extension
9:45 AM Break
10:00 AM Apple Rootstock Research / Specialty Crops Research Initiative
Gennaro Fazio, Cornell University / USDA-ARS
11:00 AM TBD
11:45 AM Maine State Pomological Society Business Meeting
Aaron Libby, President
12:00 PM Lunch
1:00 PM Concurrent Experiment Station Research Tours
Tree Fruit Tour –
Renae Moran, Glen Koehler, and special guest Gennaro Fazio. New Geneva apple rootstocks; and pruning techniques for high apple, peach and cherry orchards
Berry and Vegetable Tour –
David Handley and Mark Hutton. Pumpkin, sweet corn, broccoli and grape variety trials; pest update; and reduced tillage in organic systems and permanent beds; high tunnel tomatoes and strawberries; irrigation and compost application in high tunnels.
3:00 PM Adjourn

Thank you to our sponsors, Crop Production Services, Maine State Pomological Society and Maine Vegetable and Small Fruit Growers Association.

Directions to Highmoor Farm, 52 US Route 202, Monmouth, Maine 04259 (207.933.2100)
Traveling North on I-95: Drive north on the Maine Turnpike (I-95) and take Exit 86 in Sabattus. Turn left onto Route 9/Middle Road. Travel about 2 miles on Route 9 East, then turn left onto Route 132. After 4.5 miles, turn left onto Leeds Junction Road. Travel about 2.8 miles, then turn right onto U.S. Route 202 and travel about 1.3 miles up the road until you see Highmoor Farm on the right.

Traveling South on I-95: Take Exit 109B in Augusta. Continue west on U.S. Route 202 and travel about 15 miles. Highmoor Farm will be on the left.


For more information about this or other workshops, please contact:

Renae Moran, Tree Fruit Specialist
University of Maine Cooperative Extension
Highmoor Farm
P.O. Box 179
Monmouth, ME 04259-0179
Tel. 207.933.2100, ext. 105
rmoran@maine.edu.


Any person with a disability who needs accommodations for this program should contact Pam St. Peter at 207.933.2100 to discuss any needed arrangements. Receiving requests for accommodations at least 10 days before the program provides a reasonable amount of time to meet the request; however, all requests will be considered.

 

 

Strawberry IPM Newsletter No. 5 – June 16, 2017

June 16th, 2017 2:22 PM

StrawberriesStrawberry IPM Newsletter No. 5 – June 16, 2017
Click on photos to enlarge.

STRAWBERRY HARVEST SEASON NEAR IN SOUTHERN MAINE

Are Your Fields Ready for Customers?

Situation:
A few ripe berries can be found in southern Maine this week. Most growers are expecting the start of the harvest season to be about a week late. Pest pressure was again very low this week, and many fields are now beyond the bloom stage when clipper or tarnished plant bug can cause significant injury.  Mites and both foliar and fruit rot diseases still have the potential to become problems, so growers should continue monitoring for symptoms, and protecting late flowering varieties with fungicides if wet weather persists in the coming days. The Strawberry IPM Newsletter will take the next couple of weeks off and return with the annual renovation issue in July.

Strawberry bud weevil or “clipper” is no longer a threat for strawberry fields in southern and mid-state regions, as few flower buds remain for them to infest. No fresh injury or clippers were found in the fields scouted this week. However, you should continue to scout for clipped buds if you still have late varieties that are flowering.

Tarnished plant bug activity continues to be very low. We have seen occasional adult bugs in the fields, but no nymphs were found this week. However, with the warmer, drier weather forecast, and more fields coming into bloom, fields should be scouted regularly and often for both adults and nymphs. The control threshold for nymphs is 4 or more flower clusters infested per 30 sampled.

Two-spotted spider mites were found over the spray threshold (25% infested leaves) in just one southern field this week. While mites have been generally low this spring, it is important to keep scouting for them through the summer to prevent heavy populations from building up and weakening the plants as they set up fruit buds and prepare for the winter.

Sap beetle on strawberry

Picnic Beetle (left) on Strawberry, photo by James Dill

Sap beetles: Growers should keep an eye out for damage as the berries start to ripen. The 1/8 inch-long, dark brown beetles chew small holes in ripening fruit, similar to slug injury. They may be found in the holes they’ve chewed, but often drop to the ground when disturbed. The best management strategy for sap beetles is good sanitation. Keep the field free of overripe fruit by picking often and thoroughly. Insecticide sprays for this pest can be effective, but should be a last resort during the harvest period. Assail®, Brigade®, Dibrom® and PyGanic® are registered for control of sap beetles with pre-harvest intervals ranging from 12 to 24 hours. Read the product label carefully for this and other application instructions and restrictions.

Birds, especially cedar waxwings, are moving into fields to feed on ripe fruit. Only by keeping a near constant presence in the field and eliminating roosting sites can you reduce the damage. Some chemical repellents containing methyl anthranilate (e.g. Avian Control®), are registered for use on strawberries. Although most scientific studies with these products have not found them to be very effective, some growers have claimed good results. Remember that songbirds are protected by law and should not be killed. However, permits may be issued for killing birds by the U.S. Fish and Wildlife Service if they receive a recommendation for such a permit from the Maine Wildlife Services Office (part of the USDA Animal and Plant Health Inspection Service) in Augusta, along with an application from the grower. There is a $50 fee for the application, and it may take over a month for the permit to be processed.  However, the permit is good for one year, so if you have problems this season, you may consider applying for a permit this winter, which would allow you an option to kill birds, if necessary, next season. The Wildlife Damage Office has recommendations for managing birds in crops, and also has some control options available through their office. For more information on permits or bird control contact the office in Augusta at 207.629.5181. The office is located in the Capital West Business Center at 79 Leighton Road in Augusta.

Powdery Mildew

Powdery Mildew, photo by David Handley

Diseases:  Once the strawberries are beyond the bloom stage, fungicide applications for gray mold can usually be stopped for the season, unless there are a lot of rainy days as the fruit progress toward harvest. Keep an eye out for brown patches or spots developing on the fruit, especially around the calyxes, that could indicate an early gray mold infection.

Powdery mildew: We’re starting to see more fields with early indications of powdery mildew. Look for upward cupping of the leaves and reddish streaking or lesions on the leaf and flower stems. Consider using a fungicide that will control powdery mildew, such as captan + Topsin-M®, or Pristine® if you’re still spraying for gray mold. Those very close to harvest may want to wait until renovation after harvest to initiate a control program.

Annual Pre-Harvest Checklist for Pick-Your-Own
It’s that time again! As harvest approaches make sure that your farm is ready to provide your customers with the best possible picking experience. Take our annual review below to evaluate your customer readiness.

  • Your phone message and web/Facebook pages with picking conditions and opening and closing times are regularly updated.
  • Signs to the farm are neat and easy to read.
  • Girl with Quarts of Strawberries

    Strawberry Harvest, photo by David Handley

    There is easy access to the fields and plenty of parking.

  • Someone is ready to greet customers and offer parking instructions and directions to the field.
  • Access to the field is free of hazards.
  • Transportation is provided for the elderly and disabled.
  • The rules regarding picking are clearly posted.
  • Someone is in the field to show customers where to pick and to answer questions.
  • There are plenty of picking containers available.
  • Clean restroom and hand washing facilities are available.
  • Someone is available to help customers carry fruit out of the field.
  • The checkouts are fast and efficient.
  • Beverages are available.
  • Shade and seats are available for customers wanting to rest.
  • The help are friendly and knowledgeable.

A friendly, clean, and organized atmosphere will leave a lasting impression on your customers, encouraging them to come back and to recommend your farm to their friends.

REMINDER:
2017-2018 New England Small Fruit Management Guides
now available. Copies can be purchased through UMaine Extension at Highmoor Farm. Cost of the guide is $12.00 plus $2.63 postage for a total of $14.63. Please send checks made payable to UMaine Cooperative Extension and mail to: Highmoor Farm, P.O. Box 179, Monmouth, Maine 04259, attention Pam St. Peter. For more information, contact Pam St. Peter at 207.933.2100 or pamela.stpeter@maine.edu.

Sincerely,

David T. Handley
Vegetable & Small Fruit Specialist

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

The University of Maine is an equal opportunity/ affirmative action institution.

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.

 

 

 

 

 

Strawberry IPM Newsletter No. 4 – June 9, 2017

June 9th, 2017 11:38 AM

StrawberriesStrawberry IPM Newsletter No. 4 – June 9, 2017
Click on photos to enlarge.

STRAWBERRY INSECT PEST PRESSURE REMAINS LOW

Continue Protection Against Gray Mold through Bloom

Berry Growers Twilight Meeting
Tuesday, June 13, 2017 at 5:30 p.m.
Lavigne’s Farm in Sanford, Maine 04073
Venue phone: 207-324-5497

Situation:
Cool, wet weather continues to slow plant and flower development throughout the state. Many “early” fields are still in the full-late bloom stage, except in southern Maine where some green fruit is visible in early fields. Insect pest pressure has generally been low, but warmer, drier weather could bring about rapid changes in the situation. The high levels of moisture mean increased pressure from fungus diseases, so keep flowers and fruit protected with timely fungicide sprays any time significant precipitation is predicted during the bloom period.

Don’t forget! Twilight Meeting Tuesday June 13th, Lavigne’s Strawberry Farm, 158 Whichers Mill Road, Sanford, Maine 04073. Albert and Patrick Lavigne’s farm features large strawberry and high bush blueberry plantings. We’ll have a tour of the berry fields and have an opportunity to look over the equipment they use in their operation. The meeting will run from 5:30 p.m. to 7:30 p.m. Two pesticide applicator recertification credits will be available for attending the meeting.

Strawberry bud weevil or “clipper” remains low for this point in the season, with just two fields finding any clipper and only one of those over threshold. Most fields in southern Maine that are now passing full bloom are beyond the stage where clipper can cause significant damage, but if you still have late varieties with flowers still in bud, continue scouting for damage. Clipper damage is likely to increase on late varieties as temperatures get warmer in the coming days. Raspberry and blackberry growers should also scout for clipper damage; clippers will also attack the buds of these plants.

Tarnished plant bug activity continues to be very low. We have seen occasional adult bugs in the fields, but no nymphs were found this week. However, with the warmer, drier weather forecast, and more fields coming into bloom, fields should be scouted regularly and often for both adults and nymphs. The control threshold for nymphs is 4 or more flower clusters infested per 30 sampled.

Two-spotted Spider Mites

Two-spotted Spider Mites, photo by David Handley

Two-spotted spider mites were found over the spray threshold (25% infested leaves) in two southern fields this week, while another field was just under threshold. Expect populations to increase in the coming days as conditions become warmer and drier. It is important to scout for mites regularly, because they can increase rapidly when conditions are favorable.

Black vine weevil & strawberry root weevil:
As we approach the harvest season remember that this is the time when adult black vine weevils and strawberry root weevils to begin to emerge and start feeding on strawberry foliage. Look for notching along the leaf edges and the presence of the black or brown snout beetles. The weevils feed mostly at night and spend the daylight hours at the base of the plants under the mulch. They will be laying eggs during the harvest and post-harvest period. The larvae or grubs feed on the strawberry plant roots through the fall, overwinter deep in the soil and feed again in the spring, causing plants to weaken and die. Badly infested beds should be plowed up as soon after harvest as possible. Bifenthrin (Brigade®) can be applied to kill the adults when they emerge and start to feed on the leaves (usually until mid-late July). Applications should be made at night when the insects are active, and the highest rate of the insecticide should be used. Platinum® can be applied in the fall as a soil drench to control grubs before they go into the winter.

Black Vine Weevil

Black Vine Weevil, photo by David Handley

Strawberry Root Weevil Grub

Strawberry Root Weevil Grub, photo by David Handley

White grubs are the larvae of scarab beetles, including Japanese beetles, Asiatic garden beetles and European chafers.  Similar to the root weevils, the grubs feed on the roots of strawberry plants, but these tend to be larger, have noticeable legs and a swollen back end. White grubs are pupating now, and adults are beginning to emerge. These will soon be laying eggs at the base of the strawberry plants and a new generation of grubs will appear during the late summer and fall. Soil drenches with Admire Pro® or Platinum® can provide control of grubs in new plantings or following renovation in older plantings. Parasitic nematodes may also be applied in the spring and/or fall. See the New England Small Fruit Management Guide for details.

Slugs may be a problem in some fields this season. Moist conditions encourage the presence of these mollusks. Slugs usually feed at night, leaving large holes and tunnels in ripening fruit. Baits such as Deadline®  and Sluggo® offer some control of slugs, but should be used prior to fruit ripening. Pay close attention to label instructions and precautions. Baits should also be applied to the fields in mid-September if slugs have been a problem, to reduce egg-laying.

Slug on Strawberry

Slug on Strawberry, photo by James Dill

Gray Mold on Strawberries

Gray Mold on Strawberries, photo by James Dill

Diseases:  Most growers are continuing to use fungicides to protect flowers from gray mold spores. So many wet days during bloom has made keeping adequate coverage challenging. We typically find two to three fungicide applications during the bloom period adequate, but with a very extended bloom and lots of moisture, additional sprays have been needed in many fields to prevent infection.

Anthracnose fruit rot:  As fruit starts to size up and ripen in fields that are wet from recent rains, be on the lookout for this fruit rot. Anthracnose is favored by warm, humid conditions and can spread rapidly under rainy, wet conditions, especially if puddles remain in a field after the rain. Anthracnose appears as black sunken lesions with wet, orange (and sometimes gray) spore masses in them. The fungus is able to multiply on leaves without visible symptoms, which is why it may appear suddenly and widespread in a field.  Fungicides such as Cabrio® and Abound® can provide good control of anthracnose fruit rot.

Powdery mildew:  No severe symptoms of powdery mildew have been observed yet, but expect to see the problem become more noticeable with warmer, dry conditions. Look for upward cupping of the leaves and reddish streaking or lesions on the leaf and flower stems. Consider using a fungicide that will control powdery mildew, such as captan + Topsin-M®, or Pristine® if you’re still spraying for gray mold.

REMINDERS:

Protecting the endangered rusty patched bumble bee as well as other pollinators of berry crops will be the topic of a meeting sponsored by Cooperative Extension, the Wild Blueberry Commission of Maine, and US Fish and Wildlife Service on Wednesday, June 21, 2017 at 6:00 pm at the Waldoboro Cooperative Extension Office. For more information contact Dave Yarborough at 1-800-897-0757.

2017-2018 New England Small Fruit Management Guides now available. Copies can be purchased through UMaine Extension at Highmoor Farm. Cost of the guide is $12.00 plus $2.63 postage for a total of $14.63. Please send checks made payable to UMaine Cooperative Extension and mail to: Highmoor Farm, P.O. Box 179, Monmouth, Maine 04259, atten. Pam St. Peter. For more information, contact Pam St. Peter at 207.933.2100 or pamela.stpeter@maine.edu.

Sincerely,

David T. Handley
Vegetable and Small Fruit Specialist

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

The University of Maine is an equal opportunity/ affirmative action institution.

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.

 

Strawberry IPM Newsletter No. 3 – June 2, 2017

June 5th, 2017 3:56 PM

Strawberry IPM Newsletter No. 3 – June 2, 2017
Click on photos to enlarge.

Strawberries

STRAWBERRY BLOOM TIME: MANAGE FUNGUS DISEASES

Scouting Report: Clipper Activity Increasing

Berry Growers Twilight Meeting
Tuesday, June 13, 2017 at 5:30 p.m.
Lavigne’s Farm in Sanford, Maine

Situation:
Many of the fields scouted this week are just in the early bloom to bloom stage, due to the continued cool, wet growing conditions. It looks as though it is going to be a late season, unless we soon see a significant change in the weather. The wet conditions should put growers on their guard for fungal diseases, including gray mold and leather rot, as these are typically more prevalent in a wet growing season.

Clipper Injury

Clipper Injury, Photo by David Handley

Strawberry bud weevil or “clipper” activity has increased over the past week.  Strawberry fields just coming into bloom in southern and coastal Maine were over the threshold of more than 1.2 clipped buds per 2 feet of row, and a spray was recommended. Clipper damage is likely to increase as temperatures warm and later varieties start coming into bloom. You should be scouting your fields for clipped buds now. Raspberry and blackberry growers beware; clippers will also attack the buds of these plants, although they do not appear to cause as much significant injury.

Tarnished plant bug activity continues to be very low.  We have seen a few more adult bugs in the fields, but no significant nymph populations. Fields coming into bloom should be scouted regularly and often for both adults and nymphs. The control threshold for nymphs is 4 or more flower clusters infested per 30 sampled.

Two-spotted spider mite numbers remain fairly low this week, although high overwintering populations have kept some fields at risk. Extended stretches of cool, wet weather can significantly reduce mite numbers, but populations can rebound quickly when warmer, drier weather returns. Two fields we scouted this week were over threshold. The extended outlook for continued cool, weather may help to keep mites in check for the near future, but it is important to scout for them regularly.

Strawberry rootworm (not root weevil) adults and feeding injury have been found on strawberry leaves in some fields this spring. The adult stage of this insect is a small (1/8”) dark brown beetle. The beetles feed on strawberry leaves during the spring and late summer, causing numerous small holes in the leaves. The adults in fields now will soon lay eggs. The larvae are small grubs that feed on the roots of strawberry plants, causing them to be stunted and weak. If these beetles and/or feeding injury is prevalent in a field, a treatment is recommended.  Sevin 50WP® is registered for control of this pest. Sprays can be timed to also control strawberry bud weevil. Strawberry rootworm should not be confused with root weevil, a larger insect that causes much more serious damage when present in a field.

Strawberry Rootworm Beetle

Strawberry Rootworm Beetle, photo by David Handley

Spittlebug

Spittlebug, photo by David Handley

Spittlebugs: The first spittlebugs of the season were found this week. The frothy spittle masses appear on the leaf stems (petioles), just below the leaflets. These typically start showing up around bloom. Although these spittlebugs don’t pose a significant threat to the plants, the frothy spittle they cover themselves with creates an annoyance for pickers. Adult spittlebugs are about ¼ inch long and bright green when they first emerge, but later turn dull yellow or brown. Spittlebugs overwinter as eggs and the nymphs emerge in late May. You should start to scout for spittlebugs when the plants are at about 10% bloom. Randomly inspect five one square foot areas per field every week. Spread the leaves and inspect the leaf bases, leaf stems, and flower stems looking for the white, frothy spittle masses. Spittlebugs tend to be a greater problem in weedy fields. Pesticides currently registered for spittlebug control include Provado®, Danitol® and Brigade®.

Diseases:  Most fields have had two to three fungicide applications to protect flowers from infection with Botrytis spores, the cause of gray mold. Infections are more likely to occur under moist conditions, so it is important to keep flowers protected during the rainy stretches we’re having. Two to three fungicide sprays 7-10 days apart are usually needed to provide good protection, but additional applications may be needed when there is continued rainfall and an extended bloom, such as we are experiencing this year.

Leather rot (Phytopthora cactorum) is certainly a concern for strawberry growers this year. This disease is more common when we have long stretches of cool, wet weather during bloom and fruit development, especially when in fields where standing water is common. Foliar sprays of Aliette®, Prophyt® or Phostrol® may be applied during bloom and fruit development to prevent leather rot.

Leaf Scorch

Leaf Scorch, photo by David Handley

Leaf spot & leaf scorch infections have been observed in most fields this week. Leaf spot usually appears on older leaves, as small purple or red spots with white centers. Under heavy infections, a number of spots may coalesce and give the leaf a burned appearance. Leaf scorch is another foliar disease with a similar diagnosis. The spots on the leaves tend to be smaller in the case of scorch, and lack the white centers. Many spots may coalesce to turn the leaves purple and necrotic, leading to the death of the leaf and weakening of the plant. Strawberry varieties vary greatly in their susceptibility to leaf spot and leaf scorch, with many having at least some resistance. However, under high disease pressure, many will show some symptoms. Fungicides registered for leaf spots include captan, Topsin-M®, Syllit®, Cabrio®, Nova® and Pristine®.

REMINDERS:

Twilight Meeting Tuesday June 13th, Lavigne’s Strawberry Farm, 158 Whichers Mill Road, Sanford, ME 04073. Albert and Patrick Lavigne’s farm features large strawberry and high bush blueberry plantings grown on very sandy soil. They have pursued extensive pond construction and irrigation development at the site and have adapted farm equipment to better suit their crops and growing practices. We’ll have a tour of the berry fields and pond construction, and discuss the challenges of water and nutrient management in these very light soils. We will also get an update on the berry pest situation around the state, and have an opportunity to look over the equipment they use and have adapted for their operation. The meeting will run from 5:30 p.m. to 7:30 p.m. We anticipate that two pesticide applicator recertification credits will be awarded for the meeting. Hold the date!

The rusty patched bumble bee was officially listed as an endangered species under the federal Endangered Species Act on March 21, 2017. Within Maine, the US Fish & Wildlife Service (USFWS) considers the rusty patched bumble bee to occur mainly in the Stockton Springs and Rockport area. Cooperative Extension, the Wild Blueberry Commission of Maine, and USFWS are holding a meeting on Wednesday, June 21, 2017 at 6:00 pm at the Waldoboro Extension Office to discuss the listing and potential restrictions to agricultural producers in the affected areas. We will also discuss measures to promote pollinator habitat and conserve native bees. For more information contact Dave Yarborough at 800-897-0757. We hope to see you June 21st.

2017-2018 New England Small Fruit Management Guides now available. Copies can be purchased through UMaine Extension at Highmoor Farm. The guide contains the latest information on management options for small fruit pests as well as cultural information. Cost of the guide is $12.00 plus $2.63 postage for a total of $14.63. Please send checks made payable to UMaine Cooperative Extension and mail to: Highmoor Farm, P.O. Box 179, Monmouth, Maine 04259, atten. Pam St. Peter. For more information, contact Pam St. Peter at 207.933.2100 or pamela.stpeter@maine.edu.

Sincerely,

David T. Handley
Vegetable and Small Fruit Specialist

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

The University of Maine is an equal opportunity/ affirmative action institution.

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.

 

 

 

 

 

 

Large Animal Carcass Management Training, August 2017, Highmoor Farm

June 5th, 2017 8:29 AM

Farmer on tractor composts large animal carcasses August 22-24, 2017
8:00 AM – 3:00 PM
Highmoor Farm, Monmouth, Maine

Cost: $575.00

Registration fee includes all instructional material, refreshments at breaks, lunches, and course materials.

Register online 

The Maine Compost Team is offering a 3-day large animal carcass management training August 22-24 at Highmoor Farm. The training will prepare participants for deployment in the event of a foreign animal disease (FAD) outbreak or natural disaster to assist with the disposal of carcasses utilizing the composting process.

This is an experiential-based program utilizing hands-on activities, problem solving scenarios, and demonstrations that will prepare participants for actual field situations.

Training Goals

  • To foster a community that is prepared to rapidly and expertly respond to large animal disasters.
  • To provide participants core compost concepts that can be applied to many different situations.
  • To gained competencies in carcass mortality management as well as have materials to be shared with others.
  • To learn how to assess and trouble shoot unique issues to effectively use compost as a disposal tool.

Directions

For more information, contact Mark Hutchinson at mhutch@maine.edu, 207.832.0343.

If you are a person with a disability and need an accommodation to participate in this program, please call Pamela Doherty at 207.832.0343 to discuss your needs. Receiving requests for accommodations at least 10 days before the program provides a reasonable amount of time to meet the request, however all requests will be considered.

Strawberry IPM Newsletter No. 2 – May 26, 2017

May 26th, 2017 1:08 PM

StrawberriesStrawberry IPM Newsletter No. 2 – May 26, 2017
Click on photos to enlarge.

SLOW GROWTH IN THE STRAWBERRY FIELDS

Mites, Clipper Activity Increasing

Berry Growers Twilight Meeting
Tuesday, June 13, 2017 at 5:30 p.m.
Lavigne’s Farm in Sanford, Maine

Situation:
Cool, wet weather predominates, slowing strawberry development. Early fields in southern Maine are coming into bloom, with flower buds just starting to emerge in later varieties. Many growers have applied their first fungicide application for gray mold. Once spray materials have dried on the plants, they are generally considered “rainfast”, unless there is more than one inch of rainfall.  At that point, it should be assumed a significant portion of the spray has been washed off, and another application will be needed to assure adequate protection.

Twilight Meeting Tuesday June 13th, Lavigne’s Strawberry Farm, 158 Whichers Mill Road, Sanford, ME 04073. Albert and Patrick Lavigne’s farm features large strawberry and high bush blueberry plantings grown on very sandy soil. They have pursued extensive pond construction and irrigation development at the site and have adapted farm equipment to better suit their crops and growing practices. We’ll have a tour of the berry fields and pond construction, and discuss the challenges of water and nutrient management in these very light soils. We will also get an update on the berry pest situation around the state, and have an opportunity to look over the equipment they use and have adapted for their operation. The meeting will run from 5:30 p.m. to 7:30 p.m. We anticipate that two pesticide applicator recertification credits will be awarded for the meeting. Hold the date!

2017-2018 New England Small Fruit Management Guides are Here! Copies are available at Highmoor Farm. The guide contains the latest information on management options for small fruit pests as well as cultural information. Cost of the guide is $12.00 plus $2.63 postage for a total of $14.63.

To order the guides, please send your check made payable to UMaine Cooperative Extension mailed to: Highmoor Farm, P.O. Box 179, Monmouth, Maine 04259, attention Pam St. Peter. For more information, contact Pam St. Peter at 207.933.2100 or pamela.stpeter@maine.edu.

Members of the Maine Vegetable & Small Fruit Growers Association (MVSFGA) or the New England Vegetable & Berry Growers Association will receive free copies of the guide. For MVSFGA membership information, contact Bill Jordan at 207.799.1040.

Strawberry bud weevil or “clipper” activity has been low in most we’ve scouted this week. Only one field in Dresden was over the threshold of more than 1.2 clipped buds per two feet of row. We are seeing the small holes in the petals of opening flowers which indicate clipper feeding activity in many fields, but the females apparently are just starting to lay eggs and clip buds. We expect clipper damage to become more prevalent as temperatures warm and later varieties start coming into bloom. You should start scouting your fields for clipped buds now. Insecticide options for clipper include Lorsban®, Brigade®, Bifenture®, Danitol®, Sevin® and PyGanic®.

Clipper on Strawberry

Clipper on Strawberry, photo by David Handley

Tarnished Plant Bug Nymph on Strawberry Blossom

Tarnished Plant Bug Nymph on Strawberry Blossom, photo by David Handley

Tarnished plant bug activity has been low so far, this season.  We have seen adults in some fields, but so far have only found one nymph, so no sprays have been recommended. The nymphs can be hard to find, especially if the plants are wet. Young nymphs are very small (2 mm), active, yellow-green insects.  It is important to scout for them regularly, as they can appear very quickly. The threshold for nymphs is 4 or more flower clusters infested per 30 sampled. Start scouting any field with open flowers now. Insecticide options for tarnished plant bug include malathion, Assail®, Brigade®, Bifenture®, Dibrom®, Danitol®, and PyGanic®.

Two-spotted Spider Mites

Two-spotted Spider Mites, photo by David Handley

Two-spotted spider mites have been found in about half of the fields we scouted this week, and were over threshold in two fields. Although mites typically proliferate under hot, dry conditions, any plantings that harbored a high mite population last fall, which was hot and dry, are likely to see a problem with mites this spring. It is important to scout for mites regularly. If 25% of leaves sampled (e.g. 15 out of 60) have any mites, a spray should be applied. Chemical control options for two-spotted spider mites include Acramite®, Savey®, Zeal®, Portal®, Vendex®, Oberon®, Brigade®, Danitol®, and JMS Stylet oil® (oils will cause plant injury if used in combination with captan or within 14 days of an application of sulfur). Be sure to use enough liquid and pressure in the spray to get good coverage on the undersides of the leaves.

Cyclamen mites:  We found one field with light symptoms of cyclamen mite injury this week.  Infested plants show weak growth and shrunken, crinkled leaves. These mites are very small and reside in the crown of the strawberry plant, feeding on the developing leaves and flower buds. They are very hard to see, even with magnification. Portal® can be effective, but must be applied in lots of water to be sure that the material is carried down into the crowns where these mites reside.

Diseases:  As the fields come into bloom it is important to protect the flowers against infection by spores of the gray mold fungus, Botrytis cinerea. Most fruit infections take place through the flowers, so control efforts should be focused on the bloom period.  Two to three sprays of fungicide are typically required to provide good protection. The first spray is usually applied at 5-10% bloom, followed by a second application at petal fall. Additional applications may be applied if there is significant rainfall between or following these two sprays.

Leather rot (Phytopthora cactorum) may become a problem in fields where standing water is common during bloom and fruit development, especially if the fields were not mulched last fall. Incidence of leather rot can be reduced by applying straw mulch between the rows to prevent berries from touching the soil and reducing soil splashing onto the berries. Foliar sprays of Aliette®, Prophyt® or Phostrol® may be applied during bloom and fruit development to prevent leather rot when there has been excess moisture in a field, especially those with a history of this problem.

Powdery mildew:  We have seen early symptoms of this fungus disease in a few fields. It will become more prevalent when warmer weather arrives. It may first appear as purple or red blotches on the leaf and flower stems. Later, upward curling leaves and white, powdery growth on the undersides of the leaves becomes evident. Check your fields for pinkish purple leaf and flower stem lesions as new leaves emerge. Pristine®, Cabrio®, Topsin-M®, captan, Procure®, Torino® and JMS Stylet oil® are registered to control powdery mildew.

Leaf Spot on Strawberry Plant

Leaf Spot, photo by David Handley

Leaf spot is a fungal disease characterized by small purple spots with white centers on the leaves. The symptoms are often first visible on the older, lower leaves but often spread throughout the foliage. Spots or lesions may also appear on the leaf and flower stems. The fungus overwinters on older leaves and spreads with rain splashing in the spring. Severe infections can weaken plants, reducing fruit size, yield, and winter survival. We have seen lots of leaf spot in fields this spring. Varieties vary quite a bit in susceptibility to this disease. If you see leaf spot in your field, you should consider using a fungicide that will provide control as part of your spray program for gray mold. Products such as Captan®, Luna Sensation®, Mervion® and Pristine® have activity on both diseases.

Sincerely,

David T. Handley
Vegetable and Small Fruit Specialist

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

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.

The University of Maine is an equal opportunity/affirmative action institution.

 

 

 

 

Strawberry IPM Newsletter No. 1 – May 22, 2017

May 22nd, 2017 3:08 PM

StrawberriesUniversity of Maine Strawberry IPM Newsletter

Strawberry IPM Newsletter No. 1 – May 22, 2017
Click on photos to enlarge.

2017 STRAWBERRY PEST MANAGEMENT SEASON BEGINS

Twilight Meeting Tuesday, June 13, Lavigne’s Farm, Sanford

Situation:
The extremely dry conditions of last year’s growing season will likely impact the 2017 berry crop. Many beds did not develop optimal plant populations because runner growth was poor, and runner rooting was delayed and weakened by the dry conditions. As a result, many beds look thinner than we would like and may have a somewhat smaller crop. On the brighter side, we are now out of the drought conditions, and there is good potential for thin plantings to recover with good runner production after harvest.

A winter that features wildly fluctuating temperatures is typically very hard on berry plants, but this past winter never saw extreme cold, and winter injury has only shown up in few plantings this spring. It has been most prevalent in older beds grown in heavier soils, and where straw mulch was not used for covering the plants. Winter injury can be diagnosed by cutting into the crowns of the strawberry plants. The internal tissue will show dark brown discoloration. To reduce the impact of winter injury, make sure the plants get plenty of water, and apply nutrients to encourage root growth and flower development, including nitrogen, calcium, and phosphorus. Heavy nitrogen fertilizer applications in the spring are not recommended, but up to 20 pounds of actual N (e.g. 125 lb. calcium nitrate) may improve early spring growth.

2017-2018 New England Small Fruit Management Guides are at the printers and will soon be available from UMaine Cooperative Extension. The guide contains the latest information on management options for small fruit pests as well as cultural information. We’ll make them available as soon as they arrive. While you’re waiting, the revised edition is already available on the UMass Extension website.

We will begin scouting strawberry fields for major insect pests next week, including volunteer farms in Wells, Limington, Cape Elizabeth, Minot, New Gloucester, Dresden, Monmouth, Wayne, and Farmington, and will be reporting our findings through this newsletter and blog on a weekly basis until harvest time. You can also get quick access to this information on the UMaine Pest Management web page at http://umaine.edu/ipm/.

The best way to manage strawberry pests is to scout your own fields regularly and often. You should start scouting regularly as soon as flower buds emerge from the crown. You should be able to identify the major pests and their damage, and be able to determine if control measures are necessary. To properly scout your fields, you may want a copy of the Strawberry Production Guide for the Northeast, Midwest and Eastern Canada. This contains detailed information on strawberry pest identification and monitoring, and also provides information on all other aspects of strawberry production. It may be purchased for $45.00 per copy from the University of Maine Cooperative Extension Publications Catalog online.

Strawberry bud weevil or “clipper” are becoming active as flower buds begin to emerge. Clipper activity has been observed in southern Maine this week. The clipper is a small weevil, which girdles strawberry flower buds, causing them to dry up and fall off the flower stalk. Scout for damage by counting the number of clipped buds in two feet of row length at five different locations in a field. If the average number of clipped buds per two-foot sample exceeds 1.2, or if live clippers are found, control measures are recommended. Damage is usually first noticed at the edges of the field. Border sprays may be effective in keeping this insect from becoming a problem in larger fields. Fields with a history of clipper problems will typically exceed threshold nearly every year. Insecticide options for clipper include Lorsban®, Brigade®, Sevin® and PyGanic®.

Clipper Beetle on Strawberry Bud

Clipper Beetle on Strawberry Bud, photo by James Dill

Large Tarnished Plant Bug Nymph

Third Instar Tarnished Plant Bug Nymph, photo by David Handley

Tarnished plant bugs adults will soon be laying eggs. Strawberries are one of their preferred hosts at this time of year. Once the eggs start to hatch, we’ll find the nymphs feeding in the flowers. The nymphs are small, active, yellow-green insects. It is important to scout for them regularly, as they can appear very quickly in warm weather. Tarnished plant bugs feed on the open strawberry flowers, causing the berries to have seedy ends. To scout for the nymphs, shake 30 flower clusters (six clusters in five different locations) over a plate. If four or more of the clusters out of the 30 sampled have any nymphs, control measures should be taken. Be on the alert and scout your fields as soon as open flowers appear! Insecticide options for tarnished plant bug include Assail®, Brigade®, Danitol®, Dibrom®, and PyGanic®.

Cyclamen mites:  Plants showing weak growth and yellow, pinkish or blackened, crinkled leaves may be infested with cyclamen mite. Cyclamen mites are very small, smaller than spider mites, and reside in the crown of the strawberry plant feeding on the developing leaves and flower buds. They are very hard to see, even with magnification. Infested plants have shrunken distorted leaves and flower stalks, and produce few, if any, marketable fruit. The miticide Portal® can be effective, but must be applied in lots of water and a spreader adjuvant to be sure that the material is carried down into the crowns where these mites reside.

Cyclamen Mite Damage on Strawberry Plant

Cyclamen Mite Damage on Strawberry Plant, photo by David Handley

Two-spotted Spider Mites

Two-spotted Spider Mites, photo by David Handley

Two-spotted spider mites can be a problem in the spring, especially for plants under row covers. This is often where we first find mites. The cool wet weather of recent weeks has kept spider mite populations low (we haven’t seen any yet), but they will reproduce rapidly when warm weather arrives, so it is important to scout for them regularly. Spider mites mostly feed on the undersides of strawberry leaves, rasping the plant tissue and sucking the sap. Infested leaves will develop yellow flecking and a bronzed appearance. The plants become weakened and stunted. Fields that have had excessive nitrogen fertilizer and/or row covers tend to be most susceptible to mite injury. To scout for mites, collect 60 leaves from various locations in the field and examine the undersides for the presence of mites. Mites are very small – you may need a hand lens to see them. Chemical control options for two-spotted spider mites include Acramite®, Portal®, Nealta® Savey®, Zeal®, Vendex®, Oberon®, Brigade®, Danitol® and JMS Stylet Oil® (oils will cause plant injury if used in combination with captan or within 14 days of an application of sulfur).

Strawberry Root Weevil Grub

Strawberry Root Weevil Grub, photo by David Handley

Root weevil management
Fields that were infested with root weevils last summer should be inspected for grubs this spring. Infested plants appear week and stunted, usually in somewhat circular patches in a field. Digging under the plants will reveal small (1/4”-1/2”) crescent-shaped legless grubs. Typically, the grubs begin to pupate when the plants are in bloom. A soil drench of Platinum® (thiamethoxam) insecticide during the spring and/or fall when the grubs are active in the soil can provide control. However, Platinum® has a 50 day pre-harvest interval, so it is too late for applications in most fruiting fields this year.  Platinum® may also be used as a pre-plant or planting treatment for root weevils. It is not too late to put on an application of nematodes to control the grubs (optimal timing is about mid-May). Two species of nematodes appear to offer the best control of root weevil grubs. Heterorhabditis bacteriophora (Hb) appears to be the best candidate for control of root weevils when the soil temperature is above 60 degrees, and is available from Green Methods, www.greenmethods.com/site-info; the Integrated Biocontrol Network, www.biconet.com; and Koppert Biological Systems, www.koppertonline.com.

Nematodes are living organisms and they can be killed if they are misapplied. Order nematodes ahead of time and be ready to apply them through a sprayer or irrigation soon after they arrive. Refrigerate them if you cannot apply right away. Do not apply nematodes using a sprayer with a piston pump. Use clean equipment, removing all screens finer than 50-mesh. Apply nematodes in early morning or evening in a high volume of water to already moist soil, pre-irrigating if needed. Apply another ¼ inch of irrigation after application to wash them onto and into the soil. Researchers and suppliers recommended 250 (if banded in the row) to 500 million per acre, at a cost of $100-$200 per acre depending on volume and source. Nematodes tend to work best in heavily infested fields. Strawberry plants can recover their vigor remarkably well if crown feeding has not occurred and diseases haven’t taken over the roots.

Once the adults become active in July, bifenthrin (Brigade®) will provide some control if used at the highest labeled rates. The best timing for this spray is at night during the peak feeding activity of adults, before they start laying eggs, or about the time harvest ends.

White Grub

White Grub, Photo by David Handley

White grubs:  Weak growth noted in fields this spring may also be the result of white grubs feeding on the roots of newer plantings. These grubs are the larvae of beetles, including European chafer and Asiatic garden beetle. They differ from the larvae of black vine weevil and strawberry root weevil in that they have legs and a swollen anterior (rear end), and they tend to be larger. Their feeding weakens the plants by reducing the number of roots. The grubs can be found by pulling up weak plants and sifting through the soil that surrounded the roots. Controlling white grubs once they have become established in a field can be difficult. These tend to be more of a problem in new fields that have been planted following a grass rotation crop, because the adults prefer to lay their eggs in sod. Admire Pro®  and Platinum® insecticides are labeled for control of white grubs and should be applied within two hours of irrigation or rainfall to be sure the chemical gets into the root zone. Admire Pro® requires a 14 day to harvest interval, while Platinum® requires a 50 day pre-harvest interval.

Diseases:  Bloom is a critical time to protect strawberry fruit against gray mold caused by the fungus Botrytis cinerea, especially when conditions have been damp. Two to three sprays of fungicide during bloom are typically required to provide good protection against this disease. If you tank mix insecticides and fungicides, avoid spraying when bees are active. Botrytis cinerea overwinters on old leaves and plant debris. Fruit infections take place almost exclusively through the flowers, so gray mold control efforts must be focused on the bloom period. If the bloom period is dry and/or good fungicide coverage is maintained, incidence of gray mold at harvest should be low.

There are several excellent fungicide choices for control of gray mold in strawberries. Elevate® (fenhexamid) has good to excellent activity against Botrytis. Captevate® is a pre-mix of captan and fenhexamid and has a broader spectrum of activity than Elevate® alone. Switch® (cyprodinil and fludioxonil), Scala® (pyramethanil) and Pristine® (pyraclostrobin and boscalid) are also excellent products for gray mold control. Topsin M® + captan is also a good fungicide combination, but remember that captan is strictly a protectant and can be washed off by rain or irrigation water. Thiram is similarly effective but also susceptible to wash-off.

The fungicides Cabrio® (pyraclostrobin) and Abound® (azoxystrobin) are NOT suitable for gray mold control, but are effective against anthracnose and other fruit rot and leaf spot diseases. All fungicides mentioned above have a 0-day pre-harvest interval, except Topsin M® (1 day) and thiram (3 days). Remember to alternate fungicides with different modes of action for resistance management purposes.

Gray Mold on Strawberries

Gray Mold on Strawberries, photo by James Dill

Red Stele Symptoms on Strawberry Plant

Red Stele Symptoms on Strawberry Plant, photo by David Handley

Red stele root rot
Although early spring conditions were not especially conducive to red stele development, you should still be alert for this root rot if any fields appear to be weak, stunted or dying. To diagnose red stele, pull up a few plants that look weak and scrape the roots of these plants to see if the center of the root, known as the stele, is rusty red in color, instead of the normal white. The red color would indicate an infection. Red stele is caused by Phytophthora fragariae, a soil pathogen that infects roots when soils are wet with temperatures around 50°F. The pathogen grows into the roots causing the plants to become weak, stunted and to eventually die. Symptoms are most evident in the spring, and can be mistaken for winter injury. Ridomil Gold®, Alliette® or Phostrol® are fungicides that can be applied in the late fall or early spring for control of red stele. In newly planted beds, RootShield® may be applied as a pre-plant root dip to help prevent infections. Many varieties have some level of resistance to the disease, but the most effective management strategy is to plant only into well-drained soils, and/or plant onto raised beds.

Powdery mildew:  This fungus disease may first show up as purple or red blotches on the leaf petioles and flower stems in strawberry fields. Most of us are more familiar with the later symptoms of upward curling of the leaves and white, powdery growth on the undersides of the leaves. Some small infections of powdery mildew were observed in southern Maine this week. Check your fields for pinkish purple leaf and flower stem lesions as new leaves emerge. Pristine®, Cabrio®, Topsin-M®, captan, Procure®, Torino® and JMS Stylet Oil® are presently registered to control powdery mildew.

Powdery Mildew

Powdery Mildew, photo by David Handley

Angular Leaf Spot

Bacterial Angular Leaf Spot, Photo by David Handley

Angular leaf spot is a bacterial disease that is characterized by translucent leaf spots that may turn yellow and eventually black. The symptoms tend to start on the lower leaves but may move upwards as bacterial spores are splashed up by rain or irrigation water. Infection of the calyxes may result in a blackening of the berry stems and caps, reducing their marketability. Bacterial angular leaf spot is favored by extended cool, wet weather and nights with temperatures close to freezing. Frequent irrigation for frost protection can greatly encourage the development and spread of the disease, as will extended cool, damp weather. Susceptibility to this disease appears to vary significantly between varieties. The copper-containing material Kocide®, can reduce the spread of this disease. Start spray applications before bloom to prevent multiplication of the bacteria on the leaves before they jump to the berry caps. Application of copper sprays after bloom can result in fruit injury and is not recommended. Hydrogen dioxide (OxiDate®) may also have some activity against angular leaf spot when used on strawberries as part of a gray mold management program.

Other Berries:

Raspberries are showing little winter injury so far, but often winter injury becomes apparent once the floricanes start to flower. Tip dieback often occurs due to winter damage to the vascular tissue within the canes. Flower buds are starting to emerge on early varieties in southern Maine. These are susceptible to damage from strawberry bud weevil or clipper, as discussed above. Look for clipped buds and weevils regularly once the buds are visible.

Highbush blueberries are showing a very impressive bloom in most fields this spring, offering the potential of a very good crop, if conditions for development are right. If fruit set is heavy, be sure to supply adequate irrigation and nutrients during the growing season to support fruit development, reduce stress on the plants and to assure good bud development for next year. Mummy berry spores will soon be active. Expect infection periods to occur over the next few weeks, anytime there is a significant moisture event (rain, mist, fog). Protectant fungicides for mummy berry include Indar®, Orbit®, and Quilt Excel®.

Twilight Meeting Tuesday June 13th, Lavigne’s Strawberry Farm, 158 Whichers Mill Road, Sanford, ME 04073. Brothers Albert and Patrick Lavigne will be showcasing their farm, which features large strawberry and high bush blueberry plantings grown on very sandy soil. They have pursued extensive pond construction and irrigation development at the site and have adapted farm equipment to better suit their crops and growing practices. We’ll have a tour of the berry fields and pond construction, and discuss the challenges of water and nutrient management in these very light soils. We will also get an update on the berry pest situation around the state, and have an opportunity to look over the equipment they use and have adapted for their operation. The meeting will run from 5:30 p.m. to 7:30 p.m. More details to follow.  Hope to see you in Sanford!

Sincerely,

David T. Handley
Vegetable and Small Fruit Specialist

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

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.

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.  A Member of the University of Maine System.

 

 

 

 

Hutton Gives Growing Produce Tips for Reducing Soil Compaction on Farms

January 20th, 2017 9:27 AM

Mark Hutton, a vegetable specialist with the University of Maine Cooperative Extension and professor in the UMaine School of Food and Agriculture, told Growing Produce there are several methods farmers can use to protect their crops from the harmful effects of soil compaction. Methods include minimizing vehicle and foot traffic in the field, alternatives to conventional tillage or no-till planting. Before farmers move in these directions though, Hutton suggests they determine if the practices will work with the cover and cash crops they plant. “It’s a different way to look at how you’re farming,” Hutton said. “One of the best things to do is to talk to other growers who are doing reduced tillage. Find out their reasons for doing it, see how it fits into their system, and think about how you can make those changes in your own operation. I don’t think these methods are harder or easier than anything else — they’re just different.”

Spotted Wing Drosophila Update: November 4, 2016

November 4th, 2016 8:44 AM

SPOTTED WING DROSOPHILA UPDATE: NOVEMBER 4, 2016

Click on photo to enlarge.

David Handley, Vegetable and Small Fruit Specialist; James Dill, Pest Management Specialist; Frank Drummond, Professor of Insect Ecology/Entomology

Spotted Wing Drosophila Trap Catch

Spotted Wing Drosophila Trap Catch, photo by Christina Hillier

Warmer temperatures and some rain have resulted in an upsurge of spotted wing drosophila trap catches in some locations, while numbers continued a downward trend in others. Once the weather settles into a colder pattern, we expect fly populations will decline rapidly, based on our experience in previous years. Our monitoring sites are done harvesting for the season, and we have removed our traps from the fields. If you still have any fields or high tunnels being harvested, drosophila pose a significant threat to any remaining fruit. A 5 to 7 day spray interval is recommended to prevent infestations of larvae. See the New England Small Fruit Management Guide for pesticide options.

We’d like to thank the farmers who allowed us to set up traps in their fields and share the data with you. Thanks also to our scouts, Lindsey Ridlon, Shannon Buzzell, Hannah Kerrigan, Danielle Murray, and Pat McManus. Special thanks to Christina Hillier for counting all those flies!

Town Spotted Wing Drosophila weekly trap catch 10/21/16 Spotted Wing Drosophila weekly trap catch 10/28/16 Spotted Wing Drosophila weekly trap catch 11/04/16
Limington* 303 301 1,077
Limerick 2,832 1,722 11,472
Wells 677 539 171
Cape Elizabeth 1,976 1,384 347
Bowdoinham 198 132 390
Dresden 4,264 431 2,992
Freeport 109 132 11
Poland Spring 3,336 1,066 442
Mechanic Falls 136 138 104
Monmouth* 4,312 625 232
Wales 176 134 298
Wayne 9,880 5,472 9,592
Farmington 2,376 1,712 968
*unsprayed planting

David T. Handley
Vegetable and 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

For more information on identifying spotted wing drosophila (SWD) and updates on populations in Maine, visit our SWD blog.

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