Weekly Field Crops Pest Report 2009

View from the Field

Ken Wise
NYS IPM

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Soybean aphid populations were on the increase statewide this week. Mike Stanyard and Keith Waldron report that some soybean fields were over the 250 aphids per plant threshold. Several fields received an insecticide treatment for the aphids.
Mike Stanyard reports very high infestation levels of slugs in black turtle beans, soybeans and corn. In some cases many of the plants in the field were gone. Mike set out a slug bait trial and seems to have had a good response. See the article below for more information on slugs.

I have seen Anthracnose on lower corn leaves at the SUNY Cobleskill Farm. Conditions have been very good for this disease with the wet weather and in no-tilled fields. Anthracnose inoculum survives on the corn residue left on the surface from the previous season. Anthracnose leaf blight appears as round to elongate, tan to brown water-soaked lesions, up to 1/2 inch long and first appear on the lower leaves. Older lesions turn gray with small black specks in the center. To control anthracnose leaf blight use resistant hybrids, rotate corn with non-grass crops or cleanly plow under infected residue. For supplemental information on Anthracnose see the article below.

Dean Sprague reports that cutworm eliminated a one acre corn field. For more information on black cutworm please view the brochure on black cutworm management in field corn.

Larry Hulle reports a few corn fields that were destroyed by seed corn maggot. The fields did not receive an insecticide seed treatment and most of the seeds ever emerged.  The grower is replanting these fields and is using seed treated with an insecticide.

Weather Outlook, July 2, 2009

Drew Montreu
NOAA NE Climate Center, Cornell University

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For perhaps the first time this summer, temperatures across the state last week ended up just above normal, with almost everywhere 1 to 3 degrees warmer than average. Up in the far northeastern part of the state, there was even a sizeable area that ended the week near 5 degrees above normal. Precipitation in the west, east and south was generally 1 to 2 inches, with some locally higher amounts. Those places in the north and north-central New York mostly saw less than an inch though.

Base 50 growing degree days accumulated from 100 to 150 in the last week, thanks to the couple days of warmer weather. This creates a pretty non-uniform picture for seasonal totals. Areas south of I-90 were mostly between 600 and 800 except for the Alleghenies, which are between 500 and 600. Also, Downstate areas are closer to 1000 growing degree days. Areas in the north are generally between 400-600, with the lowest amounts in the Adirondacks, though a few places in northern New York are nearing 700. Compared to last year, Southwestern New York and places from I-88 south and east are up to 3 calendar days behind. Most other locations are 3 to 7 days behind, though there are a few places, mostly in the north, that are as much as 10 days behind. This corresponds to up to 150 growing degree days behind last year statewide, with the areas in the north the furthest behind. Southwestern New York and areas south and east of I-88 are also up to a week ahead of normal values, while everywhere else is up to a week behind. Once again, the biggest deficits are generally in the north.

A blocking pattern has created a log jam in the atmosphere that has kept an area of low pressure spinning moisture over the state the past few days. This low will be with us right into the early weekend before another one moves in next week. After another day of widespread scattered showers and storms today, the chances for showers will gradually diminish from southwest to northeast Friday and Saturday. By Sunday, there should only be a few isolated showers around. On Monday, however, the chances for rain will again begin to increase as another low moves down from the north and hangs around into the middle of next week with more showers. High temperatures will remain cool, with most areas near or just above 70 tomorrow and Saturday. Temperatures will start to climb a little, with mid 70s Sunday and mid to upper 70s Monday. As the new low comes in though, highs will retreat back into the mid 70s for the middle of next week. Low temperatures will generally be in the mid to upper 50s to near 60 through the period. Over the next five days, areas west of I-81 can expect generally less than three-quarters of an inch of rain, while places east could see up to an inch and a quarter. However, localized areas of a couple of inches could fall today alone with some of the slower moving, stronger thunderstorms. The 8-14 day outlook keeps us in this pattern, with below average temperatures and near normal precipitation.

Slugs in Corn and Soybeans

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Slugs spend the winter as eggs. The overwintering eggs are usually laid in the general area where slugs were feeding the previous spring, summer, and fall. Thus, if they were a problem in an area last year, there’s a good chance they will be back for more. Slugs will attack seedlings and lower leaves, leaving coarse, irregular holes and characteristic “slime trails” in their wake. Feeding may result in serious injury and even stand reduction under severe infestations.

Slugs prefer cool and moist conditions, and they thrive when there are hideouts in the field, such as in the cover provided by debris on the soil surface. Slugs tend to feed most when temperatures are in the mid 60’s. Stand reduction problems have typically been worst during wet, cool springs.  No-till corn and soybean fields are at highest risk from slugs.

What wheat head disease might you have?

Ken Wise
NYS IPM

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 Dr. Gary Bergstrom has reported several different wheat spike (head) diseases this week. He shared these photos and compared the differences on our weekly statewide field crops pest conference call.

Moderated Fusarium Head Blight (Wheat Scab)

The first symptom of fusarium head blight is premature bleaching of spikelets begins to appear soon after flowering.  As seen in the photo many times the heads can be partially infected with symptoms appearing on a ¼ to ½ of a spike. If high moisture conditions persist, pink edges appear on glumes and spikelets. As the disease progresses, the developing grain kernels shrink and shrivel inside the head.  Infected kernels can develop a dangerous mycotoxin

Eyespot Foot Rot (Straw Breaker)

Early spring lesions have brown centers and darker margins. Lesions penetrate the leaf sheaths and expand until they girdle the stem. Patches of dull, charcoal gray fungus may be visible on the outside of the stems. Stem bases become bleached and brittle and break over between the bottom node and the soil line. As the plants tries to mature the heads turn a bleached color. The heads are fully and not partially bleached like Fusarium Head Blight

Glume Blotch

On wheat heads the lesions begin as either grayish or brownish spots on the chaff, usually on the upper third of the glume. As lesions enlarge, they become dark brown and the centers turn grayish-white in color as tiny brown or black dots (pycnidia) develop within them.

European Corn Borer Opens the Door for Anthracnose Stalk Rot

Ken Wise
NYS IPM

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While scouting, I observed a few signs of European corn borer (ECB) in corn this week at the SUNY Cobleskill Farm. There were broken leaf midribs, frass in the whorls, and holes in the stalks. European corn borer damage can on occasion cause localized problems for field corn producers. However, while its damage may be conspicuous, it more typically does not cause significant economic losses in NYS. If a field has had a history of ECB problems producers might consider crop rotation or the use of an ECB resistant (Bt) hybrid. In addition to direct feeding damage, the holes bored by ECB larvae can provide a means for the anthracnose fungus to enter the plant. Conditions that favor anthracnose stalk rot are continuous corn, surface corn residue (minimum & no tillage) and wet, humid, warm weather. Anthracnose stalk rot symptoms may appear after tasselling. Look for vertical, tan to reddish brown, water-soaked lesions (streaks) in the rind. Lesions become large, dark brown to shiny black. The best management practices to minimize or avoid anthracnose require action before or at the time of planting, i.e. the use of diseases resistant hybrids and hybrids with a good standability rating. Crop rotation with non-grass crops and plowing under infected residue are also recommended. Fields with high amounts of anthracnose leaf blight should be checked for indications of anthracnose stalk rot. If stalk rot is found you may wish to target that field for early harvest to avoid losses associated with premature lodging. For more information on corn diseases checkout our online publication: Diseases of Corn Management Guide 72k pdf file

NYS Soybean Rust Update

Gary Bergstrom
Cornell University

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Sentinel plots in NYS are being established in Cayuga, Washington, Jefferson, Seneca and Wayne counties. Scouting in these plots should begin in the next few weeks. Another report of soybean rust on soybean in a sentinel plot was made on June 22nd in Acadia Parish in Louisiana. In 2009, soybean rust has been reported in the U.S. in Alabama, Florida, Georgia, Louisiana and Texas. Updated June 26, 2009 

Clipboard Checklist

Keith Waldron
NYS IPM

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General:
* Emergency contact information ("911", local hospital, Chem. Spill emergency contact, other?) posted in central posting area
* Maintain crop records by field, including variety, planting date, pesticides used, nutrient inputs including manure, etc.
* Watch for any patches of herbicide resistant weeds, weed escapes
* Storage areas cleaned and ready to accept hay, wheat harvest

Corn:
* Monitor fields for plant vigor, growth stage, early to mid season pest issues (European corn borer, foliar diseases)
* Gaps in row? Check for seed corn maggot, wireworm, cutworm, armyworm, seedling blights, birds, seed placement issues
* Check no-till fields/fields with high residue or weeds for slug damage
* Monitor for weeds, note presence of "who", "how many" and "where"
* Adjust post emergence weed control action

Small Grains:
* Monitor winter grains for crop stage (heading, grain fill), insect problems (cereal leaf beetle, armyworm) and foliar / head diseases
* Evaluate crop for plant vigor, lodging

Alfalfa & Hay:
* Monitor alfalfa seedings for weeds, insects & diseases.
* Check regrowth of established alfalfa stands for potato leafhopper, weed and disease problems.
* Storage areas cleaned and ready to accept incoming harvest

Soybeans:
* Evaluate stand emergence - seedling blights, seed corn maggot, weed assessment, soybean aphid, volunteer glyphosphate resistant corn

Dairy Livestock Barn Fly Management:
* Sanitation, sanitation, sanitation - clean animal resting areas, feed troughs, minimize source of moist organic matter i.e. fly breeding areas in barn and in adjacent animal loafing yard
* Check waterers, drainage, roof gutters for leaks and potential overspill
* Continue fly monitoring: install "3X5" index card fly speck monitoring cards through out barn
* Install/refresh/replenish as needed: fly tapes, insecticide baits, natural enemies (parasitoids

Storage:
* Check storage areas (bunk silos, etc.) for readiness to accept first cutting, upcoming wheat harvest
* Clean in and outside of storage bins and grain handling equipment
* Keep areas around storage bins and silos clean and mowed
* Check areas around storage bins and silos for vertebrate tunneling

Equipment:
* Note any repairs needed for recently used equipment: tractors, tillage implements, planters, etc. as they are cleaned and serviced.
* Service hay harvesting equipment as needed.
* Calibrate manure spreaders - maintain records on amount spread per field

PESTICIDE EMERGENCY NUMBERS
Emergency responder information on pesticide spills and accidents CHEMTREC:  800-424-9300
For pesticide information: National Pesticide Information Center: 800-858-7378

To Report Oil and Hazardous Material Spills in New York State: NYS Department of Environmental Conservation Spill Response:_800-457-7362 (in NYS)_518-457-7362 (outside NYS)

Poison Control Centers: Poison Control Centers nationwide: 800-222-1222. If you are unable to reach a Poison Control Center or obtain the information your doctor needs, the office of the NYS Pesticide Coordinator at Cornell University, 607-255-1866, may be able to assist you in obtaining such information.

Mark Your Calendars

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July 7, 2009 -- Cornell Seed Growers Field Day, Ithaca, NY
July 15, 2009 -- Weed Science Field Day, Thompson Research Farm, Freeville, NY (morning program)
July 15, 2009 -- NYSABA Summer, BBQ, Musgrave Farm, Aurora, NY 12:00 noon
July 15, 2009 -- Weed Science Field Day, Musgrave Farm, Aurora, NY (afternoon program)
July 23, 2009 -- Aurora Farm Field Day, Musgrave Farm, 1256 Poplar Ridge Rd, Aurora, NY
Aug. 10-14, 2009 -- Soil Health Training Workshop, Ithaca, NY

Contact Information

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Ken Wise: Eastern NYS IPM Area Educator: Field Crops and Livestock
Phone: (518) 434-1690
Fax: (518) 426-3316
Email: klw24@cornell.edu

Keith Waldron: NYS Livestock and Field Crops IPM Coordinator
Phone: (315) 787 - 2432
Fax: (315) 787-2360