In this Issue:
SPECIAL FEATURE
Corn Earworm Trap Catch and Sweet Corn Ear Infestations in Minnesota: Research Update
VEGETABLE NEWS
STRAWBERRY NEWS
The 2006 Strawberry Season: Short, Sweet and Buggy
APPLE NEWS
| Vol 3 No. 7 | June 30, 2006 |
The 2006 Strawberry Season: Short, Sweet and Buggy
Thaddeus McCamant, Specialty Crops Management Specialist, Northland Community & Technical College
The strawberry season is slowly winding down in southern Minnesota and ramping up in the northern parts of the state. Few farms in central and southern Minnesota will stay open after the Fourth of July. The short bloom time has resulted in a short picking season. If the weather had been hot the last two weeks, the picking season would have been even shorter. The cool weather during picking has improved fruit quality, and most berries have been sweet and firm.
The biggest quality problems in strawberry fields have been caused by mites, insects or frost. Clipper weevils, tarnished plant bugs, thrips and cyclamen mites have all caused economic losses in strawberry fields.
Seven strawberry farms participated in the 2006 strawberry IPM project. One skipped insecticide spray without losing yield. Two participants skipped insecticide sprays and lost yield to thrips and tarnished plant bugs. Four participants sprayed insecticides when tarnished plant bug nymphs reached a threshold of 1 nymph per ten clusters and lost no fruit to either tarnished plant bugs or thrips. There have been a few reports of people spraying insecticide and still seeing thrip damage, but those fields were sprayed with Endosulfan. According to research conducted in southern Minnesota a few years ago, Endosulfan did not control thrips as well as Lorsban or Brigade.
Cyclamen mites have flared up in many fields. I have seen cyclamen mites in both sensitive cultivars like Mesabi and Cavendish and in normally resistant cultivars such as Jewel. On the fruit, cyclamen mite damage is almost identical to thrip damage. The best way to differentiate cyclamen mite damage and thrip damage is too look at the leaves. Thrip damage occurs when the surrounding leaves are healthy, but cyclamen mites damage the leaves first and occasionally damage the fruit. The plant canopy during a severe cyclamen mite outbreak will be one fourth the height of surrounding healthy leaves. Cyclamen mites should be controlled after mowing at renovation.
ACKNOWLEDGEMENTS
Co-Editors: Bill Hutchison (hutch002@umn.edu), Department of Entomology, University of Minnesota, Jeanne Ciborowski, Minnesota Department of Agriculture, Ag. Resources Management and Development Division, and Suzanne Wold-Burkness (woldx018@umn.edu), Department of Entomology, University of Minnesota
The Newsletter is published weekly from May through August, cooperatively, by the Minnesota Department of Agriculture (MDA) and the University of Minnesota (U of MN). Reports are posted on the U of MN and MDA web sites on Fridays. If you have suggestions and/or comments, please send your contributions by 4 p.m., Wednesday to Jean Ciborowski, 651-201-6217, jeanne.ciborowski@state.mn.us, MDA, 625 Robert St. North, St. Paul, MN 55155-2538. You can access the Newsletter at the U of MN web site in htm format at: www.vegedge.umn.edu/MNFruit&VegNews/mnindex.htm and at the MDA web site in pdf format at: http://www.mda.state.mn.us/ipm/ipmnews/
Partial funding for this publication is provided through partnership agreements with the Minnesota Fruit and Vegetable Growers Association (MFVGA) and the United States Department of Agriculture – Risk Management Agency (RMA). These institutions are equal opportunity providers.
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The University, including the Minnesota Extension Service, is an equal opportunity educator and employer. ©1999-2006 Minnesota Extension Service, University of Minnesota. All rights reserved. Contact copyright@extension.umn.edu for information on reproduction or use of this material.