Strawberry IPM Newsletter No. 2 – May 17, 2013
For full page print version, please see link at the bottom. Click on photos to enlarge.
Sprayer Calibration Clinic on May 21, 2013 at 2:00 p.m.
Twilight Meeting on May 21, 2013 at 5:00 p.m.
Pikes Farm to You in Farmington, Maine
Situation: A little rain last weekend provided some relief from this very dry spring for most fields. Frost hit many fields over two to three nights early in the week, and some injury has been noted wherever irrigation wasn’t able to protect the blossoms. Plants in southern Maine are now showing open primary (king) blossoms on early varieties, while in later varieties buds are still emerging from the crown. Fields that were under row covers are in full bloom, or just beyond, suggesting that we could see some ripe fruit in just a couple of weeks, weather permitting. I am still finding winter injury, especially in older fields, where straw and or snow cover was inadequate during the coldest part of the winter. On the bright side, insect activity remains fairly low in all fields scouted this week, but it is important to keep scouting during the bud emergence through bloom stages, because this is when the plants are most susceptible to clipper and tarnished plant bug. Bloom is also the most critical stage for preventing infestation by Botrytis spores, which cause gray mold.
Sprayer Calibration Clinic and Twilight Meeting
The University of Maine Cooperative Extension and the Maine Vegetable and Small Fruit Growers Association will hold a sprayer calibration clinic for airblast sprayers at David Pike’s Farm to You in Farmington on Tuesday, May 21 at 2:00 p.m. George Hamilton with the University of New Hampshire Cooperative Extension will demonstrate new tools for making sure your sprayer is delivering the correct rate of pesticides to your crops. Having a sprayer properly calibrated will improve the effectiveness of your sprays, and can save you money by reducing the amount of pesticide used and reducing crop losses due to pests. Participants will receive two pesticide applicator recertification credits. The calibration clinic will be followed at 5:00 p.m. by a tour of David Pike’s strawberry and vegetable fields. David has been a leader in innovative strawberry production techniques, including raised beds, plastic mulch, fertigation, fall cropping, and season extension. There will be some new low tunnel technology on display, as well as replant experiments and new varieties on trial. One pesticide applicator recertification will be awarded for the meeting. The location is 115 Mount View Road. (corner of Routes 2 & 4 and the Whittier Road) in Farmington, ME 04938. There will be signs posted. The farm phone number is 207.778.2187. Cost for the clinic is free and no registration is required. Hold the date!
Drip Irrigation Workshop
Wednesday, May 22, 2013, 3:00 p.m. to 6:00 p.m. at the Sherman Farm, 2679 East Conway Road, Center Conway, NH 03813. The farm phone number is 603.939.2412.
The purpose of this meeting is to review what drip irrigation options and strategies vegetable and fruit growers should be considering for the coming growing season. Trevor Hardy, of Brookdale Fruit Farm and George Hamilton, UNH Cooperative Extension will present a hands-on demonstration on setting up a drip irrigation system and describe the various components of a system, including set ups for high tunnels. Toro Irrigation Representative Bill Wolfram will also be present. The meeting will begin at 3:00 p.m. and will run until around 6:00 p.m.
For more information contact:
Olivia Saunders, UNH Extension Field Specialist
603.447.3834, e-mail: firstname.lastname@example.org, OR
George Hamilton, UNH Extension Field Specialist,
603.641.6060, email: email@example.com.
2013-2014 New England Small Fruit Management Guides are now available at Highmoor Farm. This new, updated edition of the guide contains the latest information on management options for small fruit pests as well as cultural information. Cost of the guide is $10.00 plus $2.53 postage for a total of $12.53. To order a guide, 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 933.2100 or firstname.lastname@example.org.
Strawberry bud weevil or “clipper” should now be coming active as flower buds emerge. We have not found clipper at levels over threshold in any fields scouted to date, but it is important to keep a sharp lookout for clipped buds now, especially along wooded borders of the field. If the average number of clipped buds exceeds 1.2 per two feet of row, or if live clippers are being found, control measures are recommended.
Tarnished plant bug adults are being reported in apple orchards in southern Maine, but we have not yet found any nymphs in the strawberry fields we have scouted. Strawberries are preferred hosts at this time of year, so we should expect to start seeing both adults and nymphs soon. 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 blossoms start to open.
Cyclamen mites: We have found symptoms of cyclamen mites in several plantings this spring. Symptoms include weak growth, crinkled leaves and yellow, pinkish or blackened discoloration. Cyclamen mites are too small to be seen without magnification and reside in the crown of the strawberry plant feeding on the developing leaves and flower buds. Miticides must be applied in lots of water to be sure that the material is carried down into the crowns where the mites reside.
Two-spotted spider mites have been found exceeding the management threshold at one southern location this week, in a field that was under row covers. This is often where we first find mite problems. Expect mite problems to increase as the temperature increases, especially under dry conditions.
White grubs: We have had several reports of white grub infestations in fields this spring. Weak plant growth may be the result of grubs feeding on roots. These grubs are the larvae of beetles, including European chafer and Asiatic garden beetle. The grubs have legs and a swollen anterior (rear end). The grubs can be found by pulling up weak plants and sifting through the soil that surrounded the roots. Controlling white grubs when they are established in a field is difficult. Admire Pro® is labeled for control of white grubs and should be applied within two hours of irrigation or rainfall to get the chemical into the root zone. There is still time to apply nematodes to control the grubs. (Optimal timing is about mid-May.) Two species of nematodes appear to offer the best control. Heterorhabditis bacteriophora (Hb) is the best candidate when the soil temperature is above 60 degrees (‘J-3 Max Hb’ from The Green Spot Ltd., ‘GrubStake Hb’ from the Integrated Biocontrol Network, ‘Larvanem’ from Koppert Biological Systems.
Diseases: Just a reminder that bloom is the critical time to protect strawberries from developing gray mold caused by the fungus Botrytis cinerea. Two to three sprays of fungicide during bloom are typically required to provide good protection against this disease. Any moisture, including irrigation, fog, or even pesticide sprays can stimulate Botrytis spores to germinate. Fruit infections take place almost exclusively through the flowers, so gray mold control efforts must be focused on the bloom period.
David T. Handley
Vegetable & Small Fruit Specialist
Highmoor Farm Pest Management
P.O. Box 179 491 College Ave
Monmouth, ME 04259 Orono, ME 04473
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.
Any person with a disability who needs accommodations for these programs should contact Pam St. Peter at 207.933.2100 or TDD 1.800.287.8957 to discuss their needs at least 7 days in advance.
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.
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Image Description: Strawberry Frost Injury
Image Description: Clipper Injury
Image Description: First Instar Tarnished Plant Bug Nymph
Image Description: Two-spotted Spider Mites