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Weekly Field Crops Pest Report 2009

June 18, 2009                Volume 8 Number 9

1. View from the Field

2. Weather Outlook 6/18/09

3. Be Ready for Potato Leafhopper before the damage occurs!

4. Not too Early to think about Stored Grain Pests

5. Black Cutworm in Field Corn

6. NYS 2009 Asian Soybean Rust Status

7. Fusarium head blight (FHB) Update

8. Alfalfa Weevil Prediction for NYS – the end is near?

9. Clipboard Checklist

10. Mark Your Calendars

11. Contact Information

View from the Field

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Alfalfa leaf tip feeding by alfalfa weevils is still being reported both in first cutting and re-growth alfalfa across New York. The good news is that many alfalfa fields also contain increasing numbers of alfalfa weevil pupa cocoons as seen below:

The presence of alfalfa weevil cocoons indicates the population of this insect is maturing and will soon cease causing leaf feeding damage. Once they pupate the emerging adults leave the field for overwintering sites and alfalfa weevil season is over for this year. 

Currently, potato leafhopper can be found at low levels in alfalfa statewide. Remember, initial populations of this insect travel on weather fronts to reach NY and infestation levels can increase very quickly. Keep a close eye on this and scout fields weekly.

Mike Stanyard reports black cutworm in several corn fields of NW New York. Cutworms have been typically large, 1 inch or so long, and burrowing into young corn stems. See article below on black cutworm. Mike also reports slug damage in no-till soybean fields and presence of soybean aphids. Aphid populations are low at this time ranging from trace occurrence to < 50 per plant. Beneficial insect populations in monitored soybeans are also low at this time.

Here is one for the record books! Mike Stanyard reports an unusual insect pest infestation: alfalfa weevil larvae feeding on soybeans, with pupating and adult alfalfa weevil also observed. The closest alfalfa field was > 100yards away. See photo below and believe!

 Pete Barney (CCE St. Lawrence County) reports finding potato stem borer infesting corn fields in the north country. Potato stem borer (PSB) are a sporadic minor pest of corn in New York. Pete suggests the PSB moths were probably attracted to la eggs in quackgrass or other large stemmed weeds in corn fields. After the weeds are sprayed they young larvae will switch feeding to the corn.  For more information see our fact sheet on potato stem borer.

Gary Bergstrom (Cornell Plant Pathology) reports finding Cephalosporium stripe in several fields of winter wheat. The disease organism is Cephalosporium gramineum, a soil borne fungus. When wheat is follows other small grains like winter barley, rye, and triticale can increase the chance of infection. This fungus can live in the soil 4 to 5 years. The first sign of the disease occurs in the spring with yellow stripes running the length of the leaf, sheaths and stems. Sometimes the stripes have thinner brown streaks surrounded by yellow. Plants may become stunted and wheat heads turn white and are sterile. This disease can cause major yield losses.

Weather Outlook 6/18/09

Drew Montreui
NOAA NE Regional Climate Center, Cornell University

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Temperatures during the past week were close to normal, but most areas still ended up a couple degrees cool. Those areas in the southeast were the places that managed to get a couple of degreed warmer than average. Rainfall was highly variable last week. Areas west of Rochester, along the Saint Lawrence Sea Way, and in parts of the Southern Teir got less than 1” of rain. Meanwhile, two to four inches fell from Oswego county into the Adirondacks and Downstate. Everywhere else ended the week somewhere in between these two extremes.

Base 50 growing degree days were generally in the 75 to 100 range, with scattered pockets of 100-125. The Alleghenies and Adirondacks saw only 50-75. For the season, this puts areas south of roughly I-90 between 400-600, with 200-400 north of I-90.  Compared to last year, these totals are slightly behind. Most areas are just 3 to 7 calendar days behind, but the North Country is 7 to 10 days behind. Areas in the south are closer to 1 to 4 days behind.  Compared to normal, areas south of I-90 are 1 to 3 calendar days ahead, with some areas in the southeast as much as a week ahead. The opposite is true north of the Thruway, with most areas 3 to 7 days behind, with a pocket along the St. Lawrence seaway as much as two weeks behind.

The forecast for the near term is wet as another frontal complex with areas of low pressure has set up near us. This has been giving us the rain since last night. Tomorrow looks a little drier, though scattered thunderstorms are possible, especially across the west. Saturday is again looking very wet though, with widespread rain. At least rain showers will stick around, with steadier rains east on Sunday before things start to dry out Monday with just a couple showers. By Tuesday and Wednesday, most areas should stay dry. High temperatures will be in the low to mid 70s both Friday and Saturday, with mid to upper 70s Sunday and Monday. Some 80s should start showing up by Tuesday and into next week. Low temperatures will be mild with the clouds and rain the next few days, with lows generally near 60. Expect lows to be a couple degrees cooler on Tuesday. For the next five days, there is a good chance that most locations will get or exceed 1.5” of rain. There is potential for some areas to get over 3 or 4 inches, especially in the southern and eastern parts of the state. The 8 to 14 day outlook finally has some good news, with near normal precipitation AND near normal temperatures expected.

Be Ready for Potato Leafhopper before the damage occurs!

Ken Wise

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As temperatures increase and weather fronts roll through NY, so does the risk of potato leafhopper populations reaching levels damaging to alfalfa yields and quality. Do you know what to do if a field reaches an action threshold for potato leafhopper in alfalfa? Here are the management options for potato leafhopper in alfalfa!

Option 1: Early Harvest

You can harvest the alfalfa early to control potato leafhoppers if the field is within a week to ten days of a scheduled harvest. By harvesting the alfalfa early, you’ll prevent potato leafhopper from reaching infestation levels that can cause yield and quality loss to the forage. Make sure that the whole field is harvested at the same time. If a field is not clean harvested then the alfalfa that has not been cut will serve as a refuge for potato leafhoppers and can re-infest; thus severely damaging alfalfa re-growth.

Option 2: Use an Insecticide

To protect yield and health of new seedings and established alfalfa, insecticide control can be warranted when a field is not within a week of harvest. For selection of an insecticide consult the current issue of Cornell Guide for Integrated Field Crop Management. Remember to read the label and be aware of blooms, bees and the days until harvest restrictions.

Option 3: Plant Potato Leafhopper Resistant Alfalfa

A third option for control is planting potato leafhopper resistant alfalfa. Obviously, it is a little late for this season’s crop but something to consider for future seedings. Research has shown that potato leafhopper resistant alfalfa is consistently higher in quality than susceptible alfalfa varieties with or without potato leafhopper pressure. PLH resistant varieties yields are comparable and generally better than susceptible varieties when PLH are present. A bonus benefit is that currently available alfalfa varieties with PLH resistance have come down in price over the past several years.

Not too Early to think about Stored Grain Pests

Keith Waldron

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It won't be long before wheat heads begin to lighten in color indicating harvest time is near. This year's strong commodity prices prompt much anticipation for a profitable harvest. With that in mind, it is not too early to begin preparing for harvest and checking the readiness of your on-farm storage bins. To maintain the profits a good yield can bring, make and follow a plan to protect the grain while in storage. Remember: Grain storage will not improve grain quality. However, proper management of grain during storage will protect the quality present at harvest.

The IPM approach for stored grain protection includes a combination of sanitation, well-sealed bins, frequent monitoring for temperature, moisture and insect populations, aeration to cool grain in the fall, and pest management treatments as needed. Stored grain management begins with "an ounce of prevention". This article will highlight some steps one can take now to protect stored grain before it is harvested. The following pre-harvest information was "gleaned" whole or in part from Stored Grain IPM information from Oklahoma State University Stored Products Research & Education Center and Purdue University. Source URL's are provided at end of this article.

Insect infestations are the more common stored grain pest issues one might encounter. Insect infested grain can be docked at time of sale. Most common grain bin insect problems can be traced back to infestations in previously stored material, cracked grain and grain fines and trash. The key to prevention is SANITATION - clean out the bin every time it is emptied. How clean? If you can tell what was stored in the bin the last time it was used, it needs more cleaning. In addition to insects, birds and rodents are also attracted to left over and spilled grain. Lights mounted on or in close proximity to grain bins may attract unwanted stored grain insects.
Who might the likely insect pests be? This could be the subject for a future article. In the meantime the following extension factsheets provide information to help identify the insects you may find as you clean out your storage bins: Management of Stored Grain Insects, Part II. Identification and Sampling of Stored Grain Insects and Principal Stored Grain Insect Pests of Indiana.

The following sanitation practices are recommended for managing empty storage bins.
* Remove old grain from combines, truck beds, augers and any other equipment used for harvesting, transporting or handling grain
* Remove remnants of grains from aeration systems, ducts, and exhaust systems
* Empty storage structures of old grain. The new crop should never be stored on top of old grain.
* Remove and destroy any grain from beneath, around or near the bin area. Sweep and vacuum the floors, false floors, and walls inside empty bins to remove old grain and debris. This debris usually contains insect eggs, larvae, pupae, and/or adults, all ready to infest the new grain. A shop vacuum, broom and scoop are very useful in a cleanup job, and all collected material should be discarded properly.
* Check fan boxes for possible grain pests.
* Clean/inspect/repair/replace aeration equipment and dryers
* Remove any spilled grain, weeds and tall grass around bins to reduce likelihood of rodent or insect infestations
* Check, clean or replace rodent traps.
* Check screens and porcupine wires to limit bird entry and roosting.
* For additional protection against infestation, the inside and outside surfaces, foundations and floor of a storage facility can be sprayed with residual insecticide, two to three weeks prior to harvest, to kill any insects that were not removed during cleaning and those that migrate into the bin.
* NOTE: Before using an insecticide always check current labels for state registration, grains that can be treated, rates, application sites and procedures and safety considerations. Many products now carry the statement "Do not apply directly to grain."  Some products may not be labeled for treating grain storage facilities.  Products not labeled for application to stored grain facilities should not be used as empty bin sprays. Check with grain buyer or consumer as to what is acceptable
* Clean areas surrounding storage sites that might house insects in various stages of development
* Establish a written sanitation schedule and keep appropriate records

Bin Sealing
Roof leaks are common contributors to moisture and columns of spoiled grain. Check for these leaks by looking for light coming into the bin. Moisture can also accumulate as condensation in situations requiring aeration. Moisture coming into the bin through the seal between the bin and concrete can cause spoilage around the perimeter of the bin at the base. Check the integrity of the seal since these materials can deteriorate over time. Water will run away from the seal at the base of the bin wall if the concrete is sloped away from the bin. Also check the seals around the doors and hatches.

Besides keeping grain dry, grain storages should be well sealed for two other basic reasons:

  1. to minimize grain insect entry problems into base and sidewall grain, and
  2. to minimize leakage should fumigants be used.

More information on bin sealing is available on the SPREC Web site

Source of the above stored grain pest management information: Oklahoma State University Stored Products Research & Education Center Newsletter - Spring 2004 () and OSU Extension Facts: Stored Grain Management in Oklahoma and Purdue's Stored Product Pest factsheet.

Black Cutworm in Field Corn

Ken Wise

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The cutworm adult moths ride weather fronts that carry them from the south to the Northeast.  Weedy grasses and winter annual broadleaves (especially chickweed) are favorite targets. If cutworm moths lay eggs in the field and the field is treated with an herbicide, hatching cutworm larvae bail off the dying weeds and look for greener food sources such as emerging corn seedlings. Cutworms can be an annual problem in some fields; particularly those with a history of poor weed control or with low wet areas in the field. Field margins, especially those next to ditch banks, grassy lanes, and hay fields are potential sites for infestation. Doing an early season plant population count is a good way to check corn fields for cutworm damage and other corn emergence problems.

Black cutworm larvae vary in color from light gray to black with a pale brown to black head. Larvae have a greasy, shiny appearance with coarse granules present over their body. During the day larvae burrow into the soil next to the corn plant. These larvae curl into a C-shape when disturbed. Symptoms of damage are leaf feeding, irregular holes in stems, notched and cut or missing plants. No-till fields and those with a lot of grass weeds are at particular risk to black cutworm. Monitor fields to find cutworm larvae when they are less than 1/2 inch long. If there are sufficient numbers and if 5% or more plants have been cut, an insecticide could be justified. Treat only the affected area and a 20 to 40-foot border around the infestation. Rarely does a whole field need to be treated for cutworm. Larger cutworm larvae, greater than 1/2 inch long, are much more difficult to control. If the majority of cutworm larvae are 1/2 inch long or larger their damage is already done. These large larvae are also more tolerant of insecticides, reducing the effectiveness and economic viability of this option.

NYS 2009 Asian Soybean Rust Status

Gary Bergstrom
Plant Pathologist, Cornell University

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The first detections of soybean rust on soybean in 2009 were made in Louisiana and Alabama on June 4th and 8th respectively. This is the earliest detection of soybean rust on soybean in both of these states. Limited periods of precipitation over the next several days will lead to spore deposition in the affected areas in the Florida panhandle, Georgia and the Gulf Coast. Scouting in sentinel plots in the Southeastern U.S. continues. Much of the New York State soybean acreage has been planted and begun to emerge. Please visit us again for future updates on soybean rust in the U.S. and New York state. Updated June 10, 2009

NY State Soybean Rust Hotline: 607-255-7850

NYS Soybean Rust Website

USDA Soybean Rust Website

Fusarium head blight (FHB) Update

Gary Bergstrom
Plant Pathologist, Cornell University

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The majority of New York’s winter wheat crop reached anthesis during the interval of May 31 to June 12.  The predicted risk of Fusarium head blight (FHB) was low to moderate for New York State during this interval.  Wheat is most susceptible to infection by the fungus that causes Fusarium head blight (scab) during anthesis (when anthers first emerge) and at early stages of grain development.  Even past wheat flowering stages, it is worthwhile to check the Prediction Center each day to observe weather conditions that may favor late infection of developing grains resulting in mycotoxin (deoxynivalenol) contamination if not yield loss.

For more information on current risk of Fusarium headblight in our area see: Fusarium Head Blight Risk Assessment Tool

Alfalfa Weevil Prediction for NYS – the end is near?

Ken Wise

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Current accumulated degree day data indicates alfalfa weevil populations are approaching maturity and should not be an issue much longer this season.  However…. Alfalfa weevil damage continues to be reported on alfalfa re-growth in some areas of NYS. Lingering concerns over alfalfa weevil are the result of delayed population development affected by the cooler temperatures many areas experienced earlier this season. So in addition to monitoring for PLH on alfalfa re-growth, also continue monitoring for signs of weevil feeding.  See: IPM for Alfalfa Weevil for more information on monitoring late season alfalfa weevil.

CURRENT Accumulated Growing degree days (48F Base):

March 1 -   June 18, 2009

Base 48 F
Base 50 F
Clifton Park
*Indicates missing data
Data from NEWA

Growing degree Days for Peak (50%) Occurrence of Alfalfa Weevil growth stage:

Stage or Event
Accumulated growing degree days (48F base temperature)
Eggs hatch
Instar 1
Instar 2
Instar 3
Instar 4
Adult Emergence
(Note: for alfalfa weevil predictions use Base Temp of 48F)
Source: R.I. Carruthers

Clipboard Checklist

Keith Waldron

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* 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 winter annual and other early season weeds, any patches of herbicide resistant weeds, weed escapes?
* Storage areas cleaned and ready to accept hay harvest?

* Determine plant populations, make notes on emergence problems, plant vigor, growth stage
* 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 actions

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

Alfalfa & Hay:
* Monitor alfalfa seedings for weeds, insects & diseases.
* Check regrowth of established alfalfa stands for alfalfa weevil, potato leafhopper, weed and disease problems.
* Check windrows of recently harvested alfalfa for signs of alfalfa weevil feeding damage and weevil life stage (instar cocoon).
* Storage areas cleaned and ready to accept incoming harvest?

* 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
* Order fly management materials: fly tapes, insecticide baits, natural enemies (parasitoids)

* Check storage areas (bunk silos, etc.) for readiness to accept first cutting
* Clean in and outside of storage bins and grain handling equipment

* Keep areas around storage bins and silos clean and mowed

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

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

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