In this Issue:
GUEST ARTICLE
Plan Your Irrigation Scheduling with Daily Crop “ET”
VEGETABLE NEWS
STRAWBERRY NEWS
Strawberry Weekly Pest Sampling Data
Strawberry Update
APPLE NEWS
Apple Pest Profile: Dogwood Borer (Synanthedon scitula)
Please note – there will be NO IPM Newsletter on Friday, June 16th. We'll be back in 2 weeks!
| Vol 3 No. 5 | June 9, 2006 |
Strawberry Update for the Week of June 5th
Thaddeus McCamant, Specialty Crops Management Specialist, Northland Community & Technical College
The strawberry crop is maturing rapidly. Some strawberry growers will start picking on June 10. Bloom this year lasted less than two weeks in many parts of the state. The hot, dry weather during bloom means that most fields did not have a gray mold infection period. The only diseases to worry about are leather rot and anthracnose, which can be a problem if we enter a wet cycle.
|
The hot, dry weather helped bring the thrip population to its highest level in four or five years. Thrips are very small insects that feed on strawberry and apple flowers. The best way to monitor thrips is to tap blossoms just like monitoring for tarnished plant bug. Immediately after bloom, pieces of stamens fall off the flowers. The thrips are the same size as the stamens, but they move very fast. Thrip adults are grayish-brown. Thrip nymphs are yellow. Fruit damaged by thrips tend to be small with a bronze color. The seeds on a thrip damaged berry stick out from the skin. When you eat the berry, the seeds are crunchy. Like tarnished plant bug, a moderate level of thrip damage will not be noticed by your customers, but a severe infestation will ruin your crop. The bronzing associated with thrip damage usually only occurs during hot, dry weather. Major losses from thrips are rare, but losing a crop to thrips is an unforgettable experience. Insecticides can eliminate damage associated with thrips. Brigade has been quite effective at controlling thrips. Malathion and Thiodan do not appear to be as effective as Brigade. According to some studies, thrip damage is minimized even with post bloom sprays. The official threshold for thrips is 10 insects per blossom. |
Location |
Date Sampled |
Stage |
Thrips |
Tarnished Plant Bugs |
|
xx |
xx |
|
Insects/flower |
Nymphs/flower cluster |
Adults in field |
Faribault |
6/7 |
Post bloom |
5 |
0.1 |
6 |
Alexandria 1 |
6/7 |
Post bloom |
2 |
0.2 |
8 |
Alexandria 2 |
6/7 |
Post bloom |
2 |
0 |
0 |
Aitken |
5/30 |
60% bloom |
2 |
0.05 |
4 |
Bemidji |
6/5 |
60% bloom |
0 (sprayed 6/3) |
0 |
10 |
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.
DISCLAIMER
Reference to products in this publication is not intended to be an endorsement to the exclusion of others which may have similar uses. Any person using products listed in this publication assumes full responsibility for their use in accordance with current manufacturer directions.
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.