Sweet Corn IPM Newsletter No. 7 – July 28, 2010
July 29th, 2010
For full page print version, please see link at the bottom.
Corn Earworm Catches Rise Throughout State
Fall Armyworm Counts Also Higher in Southern Maine
SITUATION
Corn harvest is in full swing in most areas of the state. Recent weather has kept the corn growing rapidly. Warm weather with clear nights has encouraged moth flights in most areas, leading to higher trap counts and tighter spray intervals to protect silking corn from both corn earworm and fall armyworm.
European corn borer: Moth counts remained low again this week. Moths were over threshold in silking corn in Nobleboro, North Berwick, and Sabattus, but all locations were already on a spray interval for Corn Earworm. No sprays were recommended due to ECB feeding injury this week.
European Corn Borer Entry Hole, photo by David Handley
Corn earworm: Pheromone trap catches continue to be low in most locations this week. Four-day spray intervals were recommended in Biddeford, one site in Cape Elizabeth, Charleston, one site in Dayton, Dresden, Levant, one site in Lewiston, Monmouth, Nobleboro, North Berwick, Old Town, and Warren. Five-day spray intervals were recommended in one site in Cape Elizabeth, Lewiston, New Gloucester, Palmyra, Readfield, Sabattus, Wales, and one site in Wells. Six-day spray intervals were recommended for silking corn fields in Corinth, one site in Dayton, Jefferson, Poland Spring, and Wayne.
Corn Earworm, photo by David Handley
Fall armyworm: Moth counts are on the rise in many locations this week. Moths exceeded threshold for silking corn in both Cape Elizabeth sites, one Dayton site, one Lewiston site, New Gloucester, and Poland Spring. All of these fields were already on a spray interval for corn earworm, so no additional spray was recommended. Fall armyworm feeding injury exceeded the 15% threshold for pre-tassel stage corn at one site in Cape Elizabeth, Oxford, Poland Spring, Warren, and Wayne. Single protective sprays were recommended on non-silking corn in all of these locations.
Male Fall Armyworm Moth, photo by David Handley
Fall Armyworm on Corn Leaf, photo by David Handley
Where the Bugs Are
If you’re interested in the pest situation in other parts of the northeast, check out the Northeast Pest Watch Monitoring Network. This Web site tracks the major insect pests such as corn earworm in the cooperating states. It is updated weekly. The web site can be found at: http://pestwatch.cas.psu.edu/.
Late Blight Hotline: Latest reports show confirmed late blight in tomatoes in Waldoboro, Warren, and Union.
For the most recent information, call the IPM Hotline at 207-760-9IPM (207-760-9476). PMO@umext.maine.edu
Late Blight on Tomato Leaves, photo by James Dill
Climate Change Video Survey
Information regarding a survey of the video Building a Resilient Coast: Maine Confronts Climate Change conducted by UMaine Cooperative Extension is below. For more information, contact Kristen Grant at kngrant@maine.edu or tel. 646-1555 X115.
Sincerely,
David T. Handley
Vegetable & Small Fruit Specialist
Highmoor Farm Pest Management Office
P.O. Box 179 491 College Ave
Monmouth, ME 04259 Orono, ME 04473
(207) 933-2100 1-800-287-0279
| Location | CEW Moths |
ECB Moths |
FAW Moths |
%ECB Damage | Recommendations / Comments |
| Biddeford | 44 | 1 | 1 | 2% | 4-day spray interval recommended for all silking corn |
| Cape Elizabeth I | 6 | 0 | 5 | 39% | 5-day spray interval recommended for all silking corn |
| Cape Elizabeth II | 17 | 0 | 39 | 10% | 4-day spray interval recommended for all silking corn |
| Charleston | 0 | 0 | 0 | 2% | 4-day spray interval recommended for all silking corn |
| Corinth | 2 | 0 | 0 | 1% | 6-day spray interval recommended for all silking corn |
| Dayton I | 3 | 0 | 1 | 3% | 6-day spray interval recommended for all silking corn |
| Dayton II | 15 | 3 | 7 | 5% | 4-day spray interval recommended for all silking corn |
| Dresden | 28 | 1 | 1 | 2% | 4-day spray interval recommended for all silking corn |
| Farmington | 0 | 1 | 0 | 1% | No spray recommended |
| Jefferson | 2 | 0 | 1 | 3% | 6-day spray interval recommended for all silking corn |
| Levant | 9 | 1 | 0 | 4% | 4-day spray interval recommended for all silking corn |
| Lewiston I | 6 | 0 | 4 | 0% | 5-day spray interval recommended for all silking corn |
| Lewiston II | 8 | 0 | 0 | 7% | 4-day spray interval recommended for all silking corn |
| Monmouth | 8 | 0 | 0 | 0% | 4-day spray interval recommended for all silking corn |
| New Gloucester | 3 | 0 | 28 | 2% | 6-day spray interval recommended for all silking corn |
| Nobleboro | 24 | 19 | 1 | 13% | 4-day spray interval recommended for all silking corn |
| North Berwick | 12 | 8 | 2 | 0% | 4-day spray interval recommended for all silking corn |
| Old Town | 19 | 0 | 0 | 3% | 4-day spray interval recommended for all silking corn |
| Oxford | 0 | 0 | 0 | 18% | One spray recommended for FAW feeding injury |
| Palmyra | 5 | 0 | 0 | 2% | 5-day spray interval recommended for all silking corn |
| Poland Spring | 3 | 2 | 4 | 15% | 6-day spray interval recommended for all silking corn |
| Readfield | 7 | 2 | 0 | 0% | 5-day spray interval recommended for all silking corn |
| Sabattus | 6 | 7 | 0 | 2% | 5-day spray interval recommended for all silking corn |
| Wales | 7 | 0 | 0 | 0% | 5-day spray interval recommended for all silking corn |
| Warren | 41 | 1 | 1 | 26% | 4-day spray interval recommended for all silking corn |
| Wayne | 2 | 1 | 1 | 18% | 6-day spray interval recommended for all silking corn |
| Wells I | 5 | 0 | 0 | 3% | 5-day spray interval recommended for all silking corn |
| Wells II | 1 | 0 | 0 | 9% | No spray recommended |
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. |
| Published and distributed in furtherance of the Acts of Congress of May 8 and June 30, 1914, by the University of 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. |
| 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. |
Would you be interested to hear and see what your neighbors, town officials, and climate experts have to say about sea-level rise, coastal flooding, and erosion? Learn what it means to you and what you can do about it.
Join us to view the Maine-based video produced by Maine and Oregon Sea Grant Programs:
Building a Resilient Coast: Maine Confronts Climate Change
This one-hour program will be rebroadcast on Maine Public Broadcasting Network on:
Saturday, August 14 at 11:00 a.m. and
Tuesday, August 17 at 9:00 p.m.
The video is also available for download in 5 short segments at www.seagrant.umaine.edu/program/sarp. We invite you to view the video on television or online. If you’d like to participate in an online survey about the video and you viewed it on television, please email Pam St. Peter at pamela.stpeter@maine.edu. After August 17, we will send a follow-up email asking viewers to complete a brief, 10-minute evaluation of the video via an online survey. Those who complete the evaluation will be offered a copy of the DVD.
Thank you for your interest and please contact us with any questions.
Sincerely,
Kristen Grant and Esperanza Stancioff
Maine Sea Grant and University of Maine Cooperative Extension
Kristen Grant
Marine Extension Associate
Maine Sea Grant and
University of Maine Cooperative Extension at the Wells Reserve
342 Laudholm Farm Road
Wells, ME 04090
207-646-1555 x115
kngrant@maine.edu
http://www.seagrant.umaine.edu
Kristen is a member of the University of Maine Marine Extension Team (MET), a collaboration of Maine Sea Grant and Cooperative Extension providing educational and applied research programs in coastal community development, ecosystem health, fisheries, aquaculture, and tourism.
Tags: corn, Highmoor Farm, pest management, sweet corn
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