Posts Tagged ‘pest management’

Strawberry IPM Newsletter No. 5 – June 15, 2018

Monday, June 18th, 2018

StrawberriesStrawberry IPM Newsletter No. 5 – June 15, 2018
Click on photos to enlarge.

HARVEST BEGINS IN SOUTHERN MAINE

Birds Causing Damage on Early Ripening Fruit

Situation:
Strawberry fields have been opening up in southern Maine this week, with growers hoping for a good weekend. The crop looks very good, although the lack of rain this spring may be having an impact on fruit size. Cedar waxwings have been a problem in many fields, pecking and feeding on the first ripe fruit. Hopefully, once pickers start to frequent the fields these birds will cause less damage, but they are very bold and hard to deter (see last week’s issue for more details on managing birds). The Strawberry IPM Newsletter will take the next couple of weeks off and return with the annual renovation issue in July.

Tarnished plant bug populations remain low, with most fields not having any nymphs, but two coastal fields were over the spray threshold of 4 or more flower clusters infested per 30 sampled. Thus, growers should continue scouting for tarnished plant bug, especially in later ripening varieties, until the green fruit start to swell.

Sap beetle on strawberry

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

Sap beetles:  Growers should keep an eye out for sap beetle 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.

Two-spotted spider mite:  Although we are finding mites in many of the fields we are scouting, most fall below the control threshold of 25% of leaves being infested. If dry weather continues to dominate, mites will likely continue to be a problem in strawberries. However, bed renovation just after harvest and the few weeks following are a good time to manage mites, as both miticides and/or predatory mites can be very effective then.

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 some 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.

Strawberry Harvest

Strawberry Harvest, photo by David Handley

  • 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.
  • 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.

Hold the Date!

Maine State Pomological Society Summer Tour on Wednesday July 18, 2018, at Dole’s Orchard in Limington.

Earl and Nancy Bunting will be hosting the Maine State Pomological Society Summer Tour at their farm this summer. Much of the focus will be on the tree fruit grown at Dole’s orchard, including apples and cherries, but there are also large plantings of pick-your-own strawberries, raspberries and blueberries.  Some of the fruit is also contracted to a local brewery. There will be a morning educational program, including talks from research and Extension Specialists, followed by lunch and afternoon tours of the fields and orchards led by Earl and Nancy. Plan to come visit this beautiful farm with us! Pre-registration is requested so we know how many lunches to request. Please contact Renae Moran or Pam St. Peter at 207.933.2100 or pamela.stpeter@maine.edu for more information.

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

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. 4 – June 8, 2018

Friday, June 8th, 2018

StrawberriesStrawberry IPM Newsletter No. 4 – June 8, 2018
Click on photos to enlarge.

EARLY STRAWBERRY FIELDS HARVESTING SOON

Insect and Mite Counts Generally Low, but Fruit Rots Still a Threat

Situation:
A little helpful rain has fallen in most parts of the state this week, but most fields are still quite dry. A few ripe strawberries are now appearing in southern Maine in fields that used row covers this spring. We had a good crowd at the berry and vegetable twilight meeting at Pineland farms this week. Despite a passing shower, participants got a tour of the operation, including over 20 acres of strawberries, and were treated to a few early ripe “Wendy” strawberries from the field.  Thanks to Justin Gray, Manager of Pineland’s Produce Division and his crew for being great hosts of this event.

Strawberry bud weevil or “clipper”:  Although we have found a few live clippers this week, most fields in southern Maine are beyond the stage when this insect can cause significant injury, except on very late-blooming varieties such as “Malwina” and perhaps “Valley Sunset”. Growers in more northern areas with plants still in the early bloom stage should remain on the lookout for clipped buds.

Tarnished plant bug activity continues to be spotty around the state this week. Nymphs were only found in a few fields and under the spray threshold of 4 or more flower clusters infested with nymphs per 30 sampled. Cold temperatures have likely slowed the emergence of this insect, and populations could rise quickly once temperatures rise. Growers should continue scouting for tarnished plant bug until the green fruit start to swell.

Two-spotted spider mite:  We are finding mites in most fields we are scouting, but with cooler temperatures and control efforts by growers, the numbers have been quite low, well below the spray threshold of 25% of leaves infested. Only one site in Bowdoinham had mite numbers over the recommended spray threshold. Mite populations can increase rapidly under warm, dry conditions, so it is important to continue scouting for them through the season.

Black Vine Weevil

Black Vine Weevil, photo by David Handley

Strawberry Root Weevil Grub

Strawberry Root Weevil Grub, photo by David Handley

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 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.

Diseases:  Late blooming varieties may still need protection against infection from Botrytis gray mold spores, especially if there is any wet weather predicted for your area. Two to three bloom sprays typically offer the best protection against this fruit rot, beginning at early bloom and ending at petal fall or just after, unless prolonged wet weather necessitates additional sprays to assure the blossoms are protected.

Leaf Spot on Strawberry Plant

Leaf Spot, photo by David Handley

Leaf diseases:  Powdery mildew has not yet been a problem in fields that we have scouted this spring, but growers should continue to be on the lookout for symptoms of upward cupping of the leaves and reddish streaking or lesions on the leaf and flower stems. If you see powdery mildew in the field, consider using a fungicide that offers control of it, such as captan + Topsin-M®, or Pristine® if you’re still spraying for gray mold.

Leaf spot is becoming more noticeable on susceptible varieties. Small reddish-purple spots with white centers appear on the leaves, often first on the inner part of the plant canopy. They may also appear on the leaf and flower stems. Severe infections weaken plants, and can reduce fruit size, yield, and quality. If you see leaf spot in your field, you should apply 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.

Bird Damage on Strawberry

Bird Damage on Strawberry, photo by David Handley

Birds, especially cedar waxwings, will soon be moving into fields to feed on ripe fruit. Where wax wings are a problem, only keeping a near constant presence in the field and eliminating roosting sites can 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.

On-farm readiness reviews for Food Safety Modernization Act Produce Safety Rule inspections
On-farm readiness reviews are non-regulatory, free assessments of a farm’s readiness for inspection under the Food Modernization Act Produce Rule. This is a chance for you to have a conversation and walk around your farm with Produce Safety Rule experts to evaluate farm facilities and practices, and assess what you’re doing well, and identify areas for improvement in food safety practices on your farm. These reviews are meant to help farmers understand the new regulations and are not an audit or inspection. No notes or records will be taken off the farm. Before asking for a review, it is recommended that at least one person from your farm complete the Produce Safety Alliance Grower Training course.  You can contact the Maine Department of Agriculture, Conservation and Forestry for information about upcoming trainings. To sign up for an On-Farm Readiness Review (OFRR), you can call 207.764.2100 and ask to be put on the OFRR list. For more information, you can contact Linda Titus at AgMatters LLC (207.631.3303), or Dr. Robson Machado at the University of Maine Cooperative Extension (207.581.3144).

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. 3 – June 1, 2018

Friday, June 1st, 2018

StrawberriesStrawberry IPM Newsletter No. 3 – June 1, 2018
Click on photos to enlarge.

MITES AND TARNISHED PLANT BUG NUMBERS RISING

Predicted Rains May Call for Protection Against Gray Mold Infection

Berry Growers Twilight Meeting
Wednesday, June 6, 2018 at 5:00 p.m.
Pineland Farm in New Gloucester, Maine

Situation:
Many parts of the state are very dry for this time of year. While this will help reduce fungal disease infections, it is important to remember that fruit size can be negatively affected by a lack of moisture. As fruit are developing, the plants need one to two inches of water per week to prevent plant stress and assure good fruit size. If the weather is not providing this moisture, growers should irrigate to supply it. It is best to irrigate in the morning so that the plants have time to dry off before evening. This will reduce the chance of fungal diseases taking advantage of the wet conditions. Early fields in southern Maine have green fruit, with the seeds just starting to separate. Later fields are just coming into full bloom. Growers are getting ready to apply their second or third fungicide spray for gray mold before the predicted wet weather this weekend.

Strawberry Irrigation

Strawberry Irrigation, photo by David Handley

Reminder:  Twilight Meeting Wednesday June 6th, Pineland Farm, 752 Mayall Road, New Gloucester, Maine 04260. Pineland Farms has some of the largest strawberry fields in the state, all of which are irrigated. They also have significant plantings of raspberries and high bush blueberries. Their main crops, in addition to strawberries, are sweet corn, which is mechanically harvested, and pumpkins. Join us for a tour and a chance to look at some of the equipment and irrigation engineering used at this unique farm. We will also have an update on the berry pest situation around the state. The meeting will run from 5:00 p.m. to 7:00 p.m. We anticipate that two pesticide applicator recertification credits will be awarded for the meeting. Hold the date!

Strawberry bud weevil or “clipper” activity continues to be low in late fields that still have flower trusses with closed buds. Once the primary (king) and secondary blossoms have opened, it is doubtful that clipper can cause significant economic harm to the crop. This week, only one field in Dresden was over the threshold of 1.2 or more clipped buds per two feet of row. Raspberry and blackberry growers should be scouting for clippers on these crops. Past experience has shown that when clipper emerge late, as they have this year, they tend to be more prolific on brambles, although they do not appear to cause as much significant injury to these crops.

First Instar Tarnished Plant Bug Nymph

First Instar Tarnished Plant Bug Nymph, photo by David Handley

Tarnished plant bug activity has been spotty and mostly low in fields scouted this week. We have started finding very small nymphs in flower clusters, indicating that more may be showing up soon. These nymphs are very small (2 mm) and active, and will drop off the blossoms when disturbed. It is important to scout for them regularly, as they can appear very quickly. We tap 30 flower clusters in each field over a white plate and look for any nymphs that have fallen onto it. The threshold is 4 or more flower clusters infested with nymphs per 30 sampled. Insecticide options for tarnished plant bug include malathion, Assail®, Brigade®, Bifenture®, Dibrom®, Danitol®, and PyGanic®.

White grubs are the larvae of scarab beetles, including Japanese beetles, Asiatic garden beetles and European chafers. Similar to the root weevils, these grubs feed on the roots of strawberry plants, but 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.

Two-spotted Spider Mites

Two-spotted Spider Mites, photo by David Handley

Two-spotted spider mite populations appear to be building in many fields this week. This is to be expected under warm, dry weather conditions. Fields in Limington, Bowdoinham and New Gloucester had mite numbers over the recommended spray threshold, and most fields had at least some mites present. 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®, and Danitol®. Be sure to use enough liquid and pressure in the spray to get good coverage on the undersides of the leaves.

Slugs may be a problem in some fields this season. Moist conditions and mulch encourage the presence of these mollusks. Slugs usually feed at night, leaving large holes in the leaves and tunnels in the 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.

Deer:  Feeding damage by deer has been observed in several fields this spring.  Rows of plants look weak or dead and have few, if any leaves, although the root system may look healthy. When deer feed on plants during the winter the plants often die, as they are exposed and the crowns are damaged. By the time the mulch is removed, the plants just look dead, and any evidence left by the deer has washed away. Deer will also feed in the spring, eating leaves and sometimes damaging crowns. If deer are a problem in your area, it is best to fence the planting before they start feeding in it.  Temporary electric fencing is usually adequate if set up correctly in a timely manner.

Diseases:  It is still important to protect the flowers and developing fruit against infection by spores of the gray mold fungus, Botrytis cinerea. Late blooming varieties are still at a susceptible stage for infection, and varieties now beyond bloom may need additional protection if we experience significant periods of cool, damp weather.

Leather rot (Phytopthora cactorum) can be a problem in fields that experience heavy downpours of rain anytime during the bloom and fruit development period. Spores are splashed up by the rain and infect flowers and fruit, causing them to develop off colors and bad flavor. Sunken black lesions on the fruit may also be visible. Applying straw mulch between the rows to prevent berries from touching the soil and reducing soil splashing onto the berries can reduce infections. Additionally, foliar sprays of Aliette®, Prophyt® or Phostrol® applied during bloom and fruit development can prevent leather rot when there has been excess moisture in a field, especially those with a history of this problem.

Powdery mildew:  We haven’t seen symptoms of powdery mildew on foliage yet, but it may become a problem with continued warm, 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.

Leaf spot has been showing up in a few late, susceptible varieties. Look for small purple spots with white centers on the leaves. The symptoms are often first visible on the older, lower leaves but then spread throughout the foliage. Spots or lesions may also appear on the leaf and flower stems. Severe infections can weaken plants, reducing fruit size, yield, and winter survival. 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. 2 – May 25, 2018

Friday, May 25th, 2018

StrawberriesStrawberry IPM Newsletter No. 2 – May 25, 2018
Click on photos to enlarge.

FULL BLOOM IN SOUTHERN FIELDS

Time to Protect Blossoms from Gray Mold Infection

Berry Growers Twilight Meeting
Wednesday, June 6, 2018 at 5:00 p.m.
Pineland Farm in New Gloucester, Maine

Situation:
Very variable weather predominates, with mixed temperatures and cloudy days, but little rainfall in most areas. Many fields experienced one or two frost events last weekend, but growers were ready and had irrigation or row covers for protection. Early fields in southern Maine are well into bloom, with flower buds just opening 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. Once more than one inch of rain has fallen, or there has been significant shoot or flower growth that is unprotected since the last application, another fungicide application should be applied to assure adequate protection. Remember to alternate fungicide and insecticide chemical families to prevent the development of pest resistance.

Twilight Meeting Wednesday June 6th will be held at Pineland Farm, 752 Mayall Road, New Gloucester, Maine 04260. Justin Gray, Manager of Pineland Farms Produce Division will discuss berry and vegetable production on this intervale site with sandy soils and extensive irrigation engineering. The farm markets both locally thorough U-pick and a farm market, and supplies large market chains through much of the season, specializing in berries, sweet corn and pumpkins. 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 5:00 p.m. to 7:00 p.m. We anticipate that two pesticide applicator recertification credits will be awarded for the meeting. Hold the date!

Strawberry bud weevil or “clipper” activity has been low in most fields that 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 that indicate clipper feeding activity in some fields, especially along the border rows, but they are just starting to lay eggs and clip buds. Expect clipper damage to increase as temperatures warm and late blooming varieties come into bloom. Insecticide options for clipper include Lorsban®, Brigade®, Bifenture®, Danitol®, Sevin® and PyGanic®. 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.

Clipper Beetle on Strawberry Blossom

Clipper Beetle on Strawberry Blossom, photo by David Handley

Tarnished Plant Bug

Tarnished Plant Bug, photo by Charles Armstrong

Tarnished plant bug activity has been low so far, this season. We have adult bugs in most fields, but so far only a few, early instar nymphs. 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 have been found in most of the fields we scouted this week, but mostly in fairly low numbers. Only one field exceeded the recommended spray threshold. Mites typically proliferate under hot, dry conditions like we had last fall, so fields may have harbored a high mite population. Once temperatures become warmer we may see more problems with mites. 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®, and Danitol®. Be sure to use enough liquid and pressure in the spray to get good coverage on the undersides of the leaves.

Cyclamen mites:  We have seen some light symptoms of cyclamen mite injury this week, but haven’t found any live mites yet. Heavily 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.

Strawberry Rootworm Beetle

Strawberry Rootworm Beetle, photo by James Dill

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.

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 haven’t yet seen early symptoms of this fungus disease in fields. However, it could become 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®, and Torino® are registered to control powdery mildew.

Leaf Spot

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 haven’t seen much 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 18, 2018

Friday, May 18th, 2018

Strawberries

University of Maine Strawberry IPM Newsletter No. 1   May 18, 2018
Click on photos to enlarge.

2018 STRAWBERRY PEST MANAGEMENT SEASON BEGINS

Twilight Meeting Wednesday, June 6, Pineland Farms, New Gloucester

Situation:
Just like last year, we may see some impact of the dry growing conditions of last summer on the 2018 harvest. Beds with inadequate or no irrigation did not develop optimal plant populations due to poor runner establishment. As a result, many beds look thinner than we would like and may have a somewhat smaller crop. However, winter survival of plants looks very good, except where deer or turkeys pulled off mulch and damaged 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 available from UMaine Cooperative Extension if you didn’t get your copy last year. The guide contains the latest information on management options for small fruit pests as well as cultural information. You can also access the guide on the UMass Extension website.

We began scouting strawberry fields for major insect pests this week, and will be working with volunteer farms in Wells, Limington, Cape Elizabeth, Minot, New Gloucester, Dresden, Monmouth, Wayne, and Farmington. The results of our scouting will be reported 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/. If you would prefer to receive this newsletter via e-mail, please give us a call at 933.2100 or send an e-mail message to: pamela.stpeter@maine.edu.

The best way to manage strawberry pests is to scout your own fields regularly and often. You should begin to scout as soon as flower buds emerge from the crowns and continue to monitor the plantings one or two times per week up until harvest. 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” will soon become active as flower buds begin to emerge. Although we did not find any clipped buds this week, we did see some chewed holes in the petals of primary flowers indicating that clippers are starting to feed. 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 on Strawberry

Clipper on Strawberry, photo by David Handley

Tarnished Plant Bug on Strawberry

Tarnished Plant Bug on Strawberry Flower, photo by David Handley

Tarnished plant bug adults are active and were found in several strawberry fields this week. These insects will soon be laying eggs in strawberry leaf and flower stems. Once the eggs start to hatch, the nymphs will begin feeding in the flowers. The nymphs are small, active, yellow-green insects. They can appear very quickly in warm weather, so it is important to scout for them regularly. Tarnished plant bugs feed on open strawberry flowers and young fruit, causing the berries to have seedy ends. To scout for the nymphs, tap or 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. These 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. We have found mites in nearly every field scouted this week, but in relatively low numbers, not yet requiring control measures. However, mites 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 weak 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, the Integrated Biocontrol Network, and Koppert Biological Systems.

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 Under Strawberry

White Grub Under Strawberry Plant, 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.

Gray Mold on Strawberries

Gray Mold on Strawberries, photo by James Dill

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.

Red Stele Symptoms on Strawberry Plant

Red Stele Symptoms on Strawberry Plant, photo by David Handley

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.

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. We haven’t found symptoms yet, but they can appear rapidly once daily temperatures get warmer. 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 Wednesday June 6th, Pineland Farms, 752 Mayall Road, New Gloucester. Justin Gray, Manager of Pineland Farms Produce Division will discuss berry and vegetable production on this intervale site with sandy soils and extensive irrigation engineering.  The farm markets both locally through U-pick and a farm market, and supplies large market chains through much of the season, specializing in berries, sweet corn and pumpkins. 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 5:00 p.m. to 7:00 p.m. More details to follow. Hope to see you in New Gloucester!

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 products with similar ingredients. Always consult product labels for rates, application instructions and safety precautions. Users of these producers assume all associated risks.

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

 

 

 

Sweet Corn IPM Newsletter No. 13 – September 15, 2017

Friday, September 15th, 2017

Sweet CornSweet Corn IPM Newsletter No. 13 – September 15, 2017
Click on photos to enlarge.

Last Issue for 2017!

INCREASING PEST PRESSURE TO END SEASON

Fresh Silking Corn Remaining Likely to Need Protection

This will be the final issue of the Sweet Corn IPM Newsletter for the 2017 season. I would like to thank all of the growers who participated in the program this year, and our team of IPM scouts, including Kara Rowley, Tammy Cushman, Lindsey Ridlon and Sean McAuley. Have questions, comments or suggestions about the program? Please call or e-mail us.

SITUATION
It appears the tropical fronts and warmer weather pushing through Maine have only brought about a moderate increase in moth activity. There may be more activity associated with tropical storms in the coming weeks, however, so the threat to any fresh silking corn that still remains may increase.

European corn borer:  No moth captures for a second week, so no real threat from European corn borer to end the season. There was no fresh larval feeding injury on younger corn and no sprays for this insect were recommended.

Corn Earworm Moth

Corn Earworm Moth, photo by David Handley

Fall Armyworm Moths

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

Corn earworm:  Moth counts rose moderately in most locations this week, keeping most fields with any fresh silk remaining on a spray schedule. A 6-day spray interval was recommended for silking corn in Oxford and one Wells site this week. A 5-day spray schedule was recommended in Auburn, one Dayton site and Sabattus. A 4-day spray interval was recommended in Cape Elizabeth, one Dayton location, North Berwick, and one Wells site.

Fall armyworm:  Moth activity was spotty around the state this week, with some sites seeing a slight increase in activity and others not. No sprays were recommended exclusively for fall armyworm on silking corn, because all sites over the 3-moth threshold were on a spray interval for corn earworm, including Cape Elizabeth, Dayton, Oxford and Sabattus. No sites were over the 15% injury threshold for larval feeding damage.

Just a reminder that fall is a great time for soil testing
Late summer and early fall are good times to seed cover crops to prevent soil erosion and to retain soil nutrients. It is also a great time to check on the health of your soil. Getting your soil test results before the ground freezes allows time to correct soil pH with additions of lime, and incorporate any needed supplements into the soil, such as phosphorus, potassium, magnesium or other nutrients to correct deficiencies, and/or manure to increase organic matter. Fall applications of lime and some nutrients (not nitrogen, as it is prone to leaching) are often better, because the fields are drier than in the spring. It’s easier to move equipment around, and the nutrients will have time to be worked into the soil before the plants need them. You can pick up soil test boxes and forms at any county office of the University of Maine Cooperative Extension, or call us here at Highmoor Farm if you’d like us to send you some. For details on soil testing at the University of Maine Analytical Laboratory and Soil Testing Service, you can visit their website at: https://umaine.edu/soiltestinglab/.

The New England Vegetable and Fruit Conference will be held in Manchester, New Hampshire on December 12, 13 and 14, 2017. Program and registration information will be coming soon. Visit the website, http://www.newenglandvfc.org/.

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

Sweet Corn IPM Weekly Scouting Summary

Location CEW
Moths
ECB
Moths
FAW
Moths
%Feeding
Damage
Recommendations / Comments
Auburn 5 0 0 5-day spray interval recommended on all silking corn
Bowdoinham 1 0 0 0% No spray recommended
Cape Elizabeth I 26 0 17 4-day spray interval recommended on all silking corn
Cape Elizabeth II 16 0 13 0% 4-day spray interval recommended on all silking corn
Dayton I 63 0 13 0% 4-day spray interval recommended on all silking corn
Dayton II 6 0 4 5-day spray interval recommended on all silking corn
Monmouth 1 0 1 0% No spray recommended
North Berwick 11 0 2 4-day spray interval recommended on all silking corn
Oxford 3 0 9 6-day spray interval recommended on all silking corn
Sabattus 5 0 4 5-day spray interval recommended on all silking corn
Wales 1 0 1 0% No spray recommended
Wayne 0 0 0 No spray recommended
Wells I 2 0 2 6-day spray interval recommended on all silking corn
Wells II 10 0 0 4-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 :
UMaine Cooperative Extension IPM
Penn State Sweet Corn IPM
UMass Extension IPM 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.

Sweet Corn IPM Newsletter No. 12 – September 11, 2017

Monday, September 11th, 2017

Sweet CornSweet Corn IPM Newsletter No. 12 – September 11, 2017
Click on photos to enlarge.

CORN PEST THREAT MODERATE BUT VARIABLE

Corn Earworm and Fall Armyworm Active in Silking Corn at Most Sites

SITUATION
Cool nights and some rainy days appear to be holding corn pests at moderate levels for this time of year, as the sweet corn season winds down. However, we may still have the remnants of tropical storms to deal with over the next couple of weeks which could cause an increase in corn earworm and/or fall armyworm populations. Next week will be the last scheduled issue of the Sweet Corn IPM Newsletter for the 2017 season.

European corn borer:  No moth captures this week, suggesting the threat of corn borer may be over for this season. Larval feeding injury on younger corn was also very low, and did not exceed threshold at any location.

Corn earworm:  Overall, moth counts remain fairly low this week, but high enough to keep some sites on a tight spray schedule for any fresh silking corn remaining. A 5-day spray schedule was recommended in Auburn, New Gloucester, North Berwick, and Wells.  A 4-day spray interval was recommended in Biddeford, Cape Elizabeth, one Dayton location, Lewiston, Monmouth and Sabattus.

Corn Earworm Feeding on Corn

Corn Earworm Feeding on Corn, photo by David Handley

Fall Army Worm on Pre-tassel Corn Plant

Fall Army Worm on Pre-tassel Corn, photo by David Handley

Fall armyworm:  Moth activity is becoming spottier from site to site, with some locations well over the 3-moth threshold for silking corn, and others seeing few, if any moths. A spray for fall armyworm on silking corn was recommended in one Dayton site, Nobleboro, Poland Spring and Wales. Other sites, including Auburn, Biddeford, Cape Elizabeth, Dayton, Lewiston, Monmouth, North Berwick, and Sabattus were also over the 3-moth threshold, but are on a spray schedule for corn earworm. No sites were over the 15% injury threshold for larval feeding damage in pre-tassel to tassel corn.

Annual end of corn season checklist:

  1. Plow down corn stalks and stubble to destroy overwintering larvae of European corn borer.
  2. Plant a cover crop, such as winter rye, to prevent soil erosion and to add organic matter to the soil.
  3. Take a soil test to determine if lime or other nutrients should be applied.
  4. Plan to rotate your crops to prevent pests from building up in any one location.
  5. Evaluate your weed management results. What worked well and what didn’t?  Which weeds were the biggest problems?  How can you improve control?

Unplowed Corn Field

Unplowed Corn Field, photo by David Handley

Oats Cover Crop

Oats Cover Crop, photo by David Handley

The New England Vegetable & Fruit Conference will be held in Manchester, NH on December 12, 13, and 14, 2017. Program and registration information will be coming soon. Visit the website: http://www.newenglandvfc.org/.

Reminder: Free disposal of unusable pesticides
The Maine Board of Pesticides Control (BPC) and the Maine Department of Environmental Protection (DEP) are sponsoring the Obsolete Pesticides Collection Program. This free program is open to homeowners, family-owned farms and greenhouses. Collections of unwanted pesticides will occur at four sites: Presque Isle, Bangor, Augusta, and Portland. Participants must pre-register by September 29, 2017Drop-ins are not permitted. To register, get details, and learn important information about the temporary storage and transportation of obsolete pesticides, go to the Maine BPC web site or call 207.287.2731.

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

Sweet Corn IPM Weekly Scouting Summary

Location CEW
Moths
ECB
Moths
FAW
Moths
%Feeding
Damage
Recommendations / Comments
Auburn 5 0 10 5-day spray interval recommended on all silking corn
Biddeford 8 0 7 4-day spray interval recommended on all silking corn
Bowdoinham 0 0 0 No spray recommended
Cape Elizabeth I 25 0 38 4-day spray interval recommended on all silking corn
Cape Elizabeth II 8 0 17 4-day spray interval recommended on all silking corn
Dayton I 41 0 107 0% 4-day spray interval recommended on all silking corn
Dayton II 0 0 5 One spray for FAW on all silking corn
Lewiston 15 0 4 4-day spray interval recommended on all silking corn
Monmouth 12 0 9 4-day spray interval recommended on all silking corn
New Gloucester 6 0 0 5-day spray interval recommended on all silking corn
Nobleboro 0 0 42 One spray for FAW on all silking corn
North Berwick 4 0 3 3% 5-day spray interval recommended on all silking corn
Oxford 1 0 2 No spray recommended
Poland Spring 0 0 12 One spray for FAW on all silking corn
Sabattus 14 0 7 4-day spray interval recommended on all silking corn
Wales 0 0 5 One spray for FAW on all silking corn
Wayne 0 0 0 No spray recommended
Wells I 5 0 2 5-day spray interval recommended on all silking corn
Wells II 4 0 2 9% 5-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:
UMaine Cooperative Extension IPM
Penn State Sweet Corn IPM
UMass Extension IPM 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.

 

 

Sweet Corn IPM Newsletter No. 11 – September 1, 2017

Friday, September 1st, 2017

Sweet CornSweet Corn IPM Newsletter No. 11 – September 1, 2017

Click on photos to enlarge.

COOL NIGHTS SLOW INSECT ACTIVITY

Anticipated Storm Fronts May Increase Moth Counts Next Week

SITUATION
Cool night temperatures have slowed development of late corn, but supply and quality look good for the holiday weekend. Many farms will soon be harvesting their last plantings of the season. The cool temperatures appear to have slowed pest activity as well, although most locations still require some protection on silking corn. The remnants of the tropical storm Harvey may drop rain and moths on Maine this weekend, so we may see a different situation next week.

Fall Armyworm on Corn Silk

Fall Armyworm on Corn Silk, photo by David Handley

European corn borer:  Low moth numbers this week, with most locations having caught none, and no locations over the threshold for silking corn. Larval feeding injury on younger corn was also low, but more small larvae were seen in pre-tassel to tasseling corn.

Corn earworm:  Moth counts are fairly low for this time of year in most locations, with several sites catching no moths. However, some sites remain on a tight spray schedule for silking corn. A 6-day spray interval for corn earworm was recommended for silking fields in Garland, Monmouth and Sabattus. A 5-day spray schedule was recommended in Wells. A 4-day spray interval was recommended in Biddeford, Cape Elizabeth, North Berwick, and Poland Spring.

Fall armyworm:  Moth activity remained high at many sites, well over the 3-moth threshold for silking corn. A spray for fall armyworm on silking corn was recommended in Lewiston, Oxford Palmyra and Wales. Other sites, including Auburn, Monmouth, Cape Elizabeth, North Berwick, Poland Spring and Sabattus were also over the 3-moth threshold, but are on a spray schedule for corn earworm. Larval feeding damage in younger corn fields in Cape Elizabeth and Oxford were over the 15% injury threshold, and sprays for pre-tassel to tassel corn were recommended.

Birds, etc.: Flocking species of blackbirds are starting to cause damage in cornfields around the state. Birds may be more of a problem in dry years, when food and water are more difficult to find. They are especially attracted to fields where corn has been allowed to get over-mature. Deer, skunks and raccoons have also been troublesome this year. For information on wildlife problems and management options, you may call the APHIS office in Augusta at 1.866.487.3297.

Bird Damage on Corn

Bird Damage on Corn, photo by David Handley

Free disposal of unusable pesticides:  The Maine Board of Pesticides Control (BPC) and the Maine Department of Environmental Protection (DEP) are sponsoring the Obsolete Pesticides Collection Program. This free program is open to homeowners, family-owned farms and greenhouses. Collections of unwanted pesticides will occur at four sites: Presque Isle, Bangor, Augusta, and Portland. Participants must pre-register by September 29, 2017Drop-ins are not permitted. To register, get details, and learn important information about the temporary storage and transportation of obsolete pesticides, go to the Maine BPC web site or call 207.287.2731.

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

Sweet Corn IPM Weekly Scouting Summary

Location CEW
Moths
ECB
Moths
FAW
Moths
%Feeding
Damage
Recommendations / Comments
Auburn 9 0 15 4-day spray interval recommended on all silking corn
Biddeford 18 0 4-day spray interval recommended on all silking corn
Bowdoinham 0 1 0 No spray recommended
Cape Elizabeth I 14 1 22 0% 4-day spray interval recommended on all silking corn
Cape Elizabeth II 30 0 29 26% 4-day spray interval recommended on all silking corn
Charleston 0 0 0 No spray recommended
Dayton I 0 0 0 0% No spray recommended
Lewiston 1 0 5 One spray for FAW
Garland 2 1 0 6-day spray interval recommended on all silking corn
Levant 0 3 0 7% No spray recommended
Monmouth 2 1 16 6-day spray interval recommended on all silking corn
Nobleboro 1 2 2 No spray recommended
North Berwick 19 0 9 3% 4-day spray interval recommended on all silking corn
Oxford 0 0 11 15% One spray for FAW
Palmyra 0 0 3 0% One spray for FAW
Poland Spring 19 0 19 14% 4-day spray interval recommended on all silking corn
Sabattus 3 3 19 6-day spray interval recommended on all silking corn
Wales 0 0 9 One spray for FAW on all silking corn
Wayne 0 0 2 No spray recommended
Wells 4 2 1 6% 5-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 :
UMaine Cooperative Extension IPM
Penn State Sweet Corn IPM
UMass Extension IPM 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.

Sweet Corn IPM Newsletter No. 10 – August 25, 2017

Friday, August 25th, 2017

Sweet Corn IPM Newsletter No. 10 – August 25, 2017
Click on photos to enlarge.

INSECT NUMBERS RISE, INCREASING THREAT

Corn Earworm, Fall Armyworm, European Corn Borer Moth Counts Higher

SITUATION
Fine weather has kept corn development at a good pace, and supply is improving. Quality has been very good in fields where growers have been able to irrigate. Pests that normally emerge later in the season, such as rust and aphids are starting to show up in many fields.

European corn borer:  Moth counts continue to be spotty, with many locations having no moths, but two having counts over the threshold for silking corn. Fields in Wayne and Poland Spring were over the 5-moth threshold for silking corn. Larval feeding injury was still low, but more small larvae are starting to show up in pre-tassel corn.

Corn earworm:  Moth counts were generally higher in most locations this week, calling for a tighter spray schedule for silking corn in most fields, although a few locations had no moths, including Monmouth, Farmington, Oxford, Levant and Palmyra. A 6-day spray interval for corn earworm was recommended for silking fields in Wales and Garland. A 5-day spray schedule was recommended in Bowdoinham, Charleston, Lewiston and one Wells site. A 4-day spray interval was recommended in Auburn, Biddeford, Cape Elizabeth, one Dayton site, Nobleboro, North Berwick, and one Wells site.

Corn Earworm Moth

Corn Earworm Moth, photo by David Handley

Fall Armyworm Moths

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

Fall armyworm:  Similar to corn earworm, moth counts were mostly higher this week, with many sites over the 3-moth threshold for silking corn. A spray for fall armyworm on silking corn was recommended at one site in Dayton, Monmouth, New Gloucester, Oxford and Sabattus.  Other sites, including Auburn, Biddeford, Cape Elizabeth, Lewiston, Nobleboro, and Wells were also over the 3-moth threshold, but are on a spray schedule for corn earworm. Larval feeding damage in younger corn was lower this week. Fields in Biddeford, and Wells were over the 15% injury threshold, and sprays for pre-tassel to tassel corn were recommended.

Corn leaf aphids have been observed in many fields this week. Colonies of these small, bluish-green insects can cover the tassels, stalks and husks. The aphids excrete a “honeydew” on the leaves and husks, which stimulates the development of sooty mold fungus. This dark, slimy coating greatly reduces the visual appeal of the ears. Sprays applied for corn earworm usually control aphids.

Aphids on corn

Aphids on Corn, photo by Kaytlin Woodman

Rust on Corn

Rust on Corn, photo by David Handley

Corn rust:  We have also seen corn rust in many fields this week. Rust is a fungus disease that causes reddish-brown pustules to form on the leaves and husks, reducing the quality of the ears. Typically, corn rust does not become a problem until late in the season. A fungicide spray for rust would only be recommended if the infection were noticed in a field prior to tasseling. Later infections are unlikely to cause enough damage to the crop to justify control measures. Materials available to control corn rust include Quadris®, Bravo®, and Quilt®.

Spotted wing drosophila:  Numbers continue to increase in fields with ripe berry fruit. Regular sprays (every 5-7 days) will be needed to prevent raspberries, blueberries and day neutral strawberries from becoming infested with larvae. Visit our Spotted Wing Drosophila blog for more information.

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

Sweet Corn IPM Weekly Scouting Summary

Location CEW
Moths
ECB
Moths
FAW
Moths
%Feeding
Damage
Recommendations / Comments
Auburn 18 0 21 4-day spray interval recommended on all silking corn
Biddeford 13 1 22 24% 4-day spray interval recommended on all silking corn
Bowdoinham 6 0 2 5-day spray interval recommended on all silking corn
Cape Elizabeth I 28 2 19 6% 4-day spray interval recommended on all silking corn
Cape Elizabeth II 20 3 11 14% 4-day spray interval recommended on all silking corn
Charleston 4 0 2 5-day spray interval recommended on all silking corn
Dayton I 1 0 4 One spray on silking corn for FAW
Dayton II 19 0 12 8% 4-day spray interval recommended on all silking corn
Farmington 0 4 0 No spray recommended
Lewiston 6 0 9 5-day spray interval recommended on all silking corn
Garland 2 0 0 1% 6-day spray interval recommended on all silking corn
Levant 0 0 0 2% No spray recommended
Monmouth 0 0 5 1% One spray on silking corn for FAW
New Gloucester 0 67 5% One spray on silking corn for FAW
Nobleboro 8 0 9 4-day spray interval recommended on all silking corn
North Berwick 32 0 9 0% 4-day spray interval recommended on all silking corn
Oxford 0 0 5 3% One spray on silking corn for FAW
Palmyra 0 0 0 0% No spray recommended
Poland Spring 6 One spray on silking corn for ECB
Sabattus 1 1 3 One spray on silking corn for FAW
Wales 2 0 2 2% 6-day spray interval recommended on all silking corn
Wayne 1 5 0 One spray on silking corn for ECB
Wells I 9 0 3 17% 4-day spray interval recommended on all silking corn
Wells II 6 4 24 8% 5-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 :
UMaine Cooperative Extension IPM
Penn State Sweet Corn IPM
UMass Extension IPM 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.

Sweet Corn IPM Newsletter No. 9 – August 18, 2017

Friday, August 18th, 2017

Sweet CornSweet Corn IPM Newsletter No. 9 – August 18, 2017
Click on photos to enlarge.

COOL NIGHTS SLOW INSECT ACTIVITY  

Silking Corn Still Needs Protection in Most Fields

SITUATION
Cool nights and dry conditions have slowed corn development, and pushed expected harvests dates back, leading to a short supply of sweet corn in some areas. Expected rain over the weekend and warmer temperatures next week should help the situation. Insect pressure has been somewhat lighter this week, although most fields still require protection for silking corn.

European corn borer:  Moth counts have been spotty around the state.  Most locations continue to see no moths, but counts have increased in a few fields. Fields in North Berwick and Poland Spring were over the 5-moth threshold for silking corn, but both sites are also under a spray interval for corn earworm, so no additional sprays should be needed. Larval feeding injury was low, with most of the injury on late corn due to fall armyworm.

Corn Earworm Moth

Corn Earworm Moth, photo by David Handley

Corn earworm:  Moth counts were generally lower in most locations this week, but still high enough to warrant a tight spray schedule for silking corn in most fields. A 6-day spray interval for corn earworm was recommended for silking fields in Wayne. A 5-day spray schedule was recommended in Bowdoinham, one Cape Elizabeth site, Levant, Poland Spring and one Wells site. A 4-day spray interval was recommended in Auburn, one Cape Elizabeth site, Lewiston, New Gloucester, Nobleboro, North Berwick, Sabattus and one Wells site.

Male Fall Armyworm Moth

Male Fall Armyworm Moth, photo by David Handley

Fall armyworm:  Similar to corn earworm, moth counts were mostly lower this week, although several sites were over the 3-moth threshold for silking corn. A spray for fall armyworm on silking corn was recommended in Biddeford.  Other sites, including Cape Elizabeth, New Gloucester, Nobleboro, Poland Spring, and Wells were also over the 3-moth threshold, but are now on a spray schedule for corn earworm. Larval feeding damage in younger corn was also lower this week. Fields in Auburn, Cape Elizabeth, New Gloucester, Poland Spring and Wells were over the 15% injury threshold, and sprays for pre-tassel to tassel corn were recommended.

Potato Leafhopper

Potato Leafhopper, photo by James Dill

Potato leafhopper alert:  We are still seeing signs of potato leafhopper in vegetable and strawberry fields this week. These small, green bullet-shaped insects feed on plant sap from the undersides of leaves, causing the leaves to become curled, stunted and yellow-streaked. Beans are often the first crop to show symptoms, but other crops are also susceptible, including potatoes and strawberries. Controls for potato leafhoppers are listed in the New England Vegetable Management Guide.

Squash vine borer:  Counts were quite low this week, with no fields over the control threshold, which agrees with data from NH. There is the possibility of a second generation emerging over the next few weeks that could threaten late squash and pumpkins or attack ripening fruit.

Spotted Wing Drosophila Larvae in Blueberry

Spotted Wing Drosophila Larvae in Blueberry, photo by David Handley

Spotted wing drosophila: Numbers have been increasing over the past week, and now threaten any soft fruit in the field, such as late raspberries and blueberries. Regular sprays will be needed to prevent such fruit from becoming infested with larvae. Visit our Spotted Wing Drosophila blog for more information.

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

Sweet Corn IPM Weekly Scouting Summary

Location CEW

Moths

ECB

Moths

FAW

Moths

%Feeding

Damage

Recommendations / Comments
Auburn 18 0 2 47% 4-day spray interval recommended on all silking corn
Biddeford 0 0 3 2% One spray recommended for FAW
Bowdoinham 5 0 2 7% 5-day spray interval recommended on all silking corn
Cape Elizabeth I 6 1 0 20% 5-day spray interval recommended on all silking corn
Cape Elizabeth II 8 9 4-day spray interval recommended on all silking corn
Charleston 1 1 0 No spray recommended
Dayton 5 1 1 1% 5-day spray interval recommended on all silking corn
Farmington 0 0 0 5% No spray recommended
Lewiston 8 1 1 4-day spray interval recommended on all silking corn
Garland 0 2 0 3% No spray recommended
Levant 5 2 3 2% 5-day spray interval recommended on all silking corn
Monmouth 0 0 1 14% No spray recommended
New Gloucester 30 0 28 16% 4-day spray interval recommended on all silking corn
Nobleboro 12 1 3 4-day spray interval recommended on all silking corn
North Berwick 15 5 1 3% 4-day spray interval recommended on all silking corn
Oxford 0 0 1 0% No spray recommended
Palmyra 0 0 1 0% No spray recommended
Poland Spring 6 9 15 20% 5-day spray interval recommended on all silking corn
Sabattus 10 0 0 0% 4-day spray interval recommended on all silking corn
Wales 1 0 0 0% No spray recommended
Wayne 3 0 0 6-day spray interval recommended on all silking corn
Wells I 6 0 2 25% 5-day spray interval recommended on all silking corn
Wells II 9 0 11 5% 4-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 :
UMaine Cooperative Extension IPM
Penn State Sweet Corn IPM
UMass Extension IPM 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.