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Weekly Field Crops Pest Report 2007

June 22, 2007                Volume 6 Number 9

1. View from the Field

2. Fusarium Head Blight (Scab) Update

3. Wheat Harvest - Preparing Bins to Avoid Pest Problems

4. Sampling for Potato Leafhopper in Alfalfa

5. Soybean Rust Update

6. NY Soybean Aphid Update

7. Clipboard Checklist

8. Growing Degree Days in NYS

9. Upcoming Events

10. Contact Information

View from the Field


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Western NY and Finger Lakes

Julie Dennis, NYS IPM

Potato leafhoppers were present at low levels in 2 Cornell alfalfa variety trials located in Wyoming County.  I only observed adult PLH, no nymphs. 

Reports of soybean aphids are coming in from around the soybean producing areas of the state.  Observations from Cortland, Cayuga, Livingston, Ontario, Seneca, and Wayne Counties indicate that aphids are at low to moderate populations.  All soybean scouting eyes should be on the lookout for aphids and, given the dry weather, spider mites. Not sure what to look for?

Spider mites on soybean leaf

 

Spider mite injury on soybean leaf:


Don’t worry yet, those photos were taken in 2005.

Another soybean pest to be on the lookout for is the bean leaf beetle.  We saw bean leaf beetle for the first time in NY late last season.  Mike Stanyard has already spotted one in Seneca County this year.

 

Photo taken by Mike Stanyard

Eastern NYS

Ken Wise

Potato leafhoppers can be found in most fields in Eastern NYS. Over the past week I have found them in Orange, Schoharie, and Columbia Counties. A field at the Cornell Research Farm in Valatie had potato leafhoppers over threshold. In three sets of 10 sweeps each there were an average of 150 potato leafhopper nymphs. The following picture shows potato leafhopper damage (also called “potato leafhopper burn”) to alfalfa field scouted this week.

 

The PLH damaged field had not been cut yet and is about 25 inches tall. In neighboring cut fields PLH were far below threshold.

Soybean aphid populations have increased in our Columbia County SBR sentinel site. Two weeks ago no soybean aphids were found, while this week there was an average of about 20aphids/plant. They ranged from 0 - 100 aphids/plant.

  

Both the Multi-colored Asian Lady Beetle (Harmonia axyridis) and the 7-Spotted Lady Beetle (Coccinella septempunctata) ) also were observed in this field.

Fusarium Head Blight (Scab) Update

Julie Dennis
NYS IPM

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One of the most devastating diseases of wheat in NY is Fusarium head blight (FHB), or scab. The disease reduces yield by decreasing the number of viable kernels, but the more significant impact is that the fungus in diseased kernels may produce a mycotoxin.

Scab is caused by airborne spores of the fungus Fusarium graminearum that dwell in nearby crop debris, including corn stalks and wheat straw. This is the same fungus that can cause root, stalk, and ear rots of corn.  Since the fungus is very widespread, likelihood of exposure is generally not reduced by crop rotation or other cultural practices.  Extended periods of warm, moist weather at crop flowering can cause the anthers to be infected just after their emergence, killing the florets and preventing kernels from developing.

Across NY, winter wheat flowered between May 29th and June 10th.  Although there were scattered rain showers on June 3, 4, and 5 in the Finger Lakes region, weather conditions were mostly dry across NY wheat areas during flowering.  Therefore, the risk of FHB infection at flowering was low.  The Penn State FHB Risk Assessment Tool continues to show low risk of disease in NY.

In locations where wet weather was experienced during wheat flowering, now is the critical time for farmers to be scouting their fields to determine if wheat is heavily infested. Symptoms of scab become visible on emerged heads soon after flowering.  During early grain fill, the disease shows up as pink to salmon orange on infected kernels.  As kernel fill progresses, the infected kernels appear bleached or chalky white. Spikes that are infected later than flowering will produce diseased kernels that are small and shriveled in appearance.  Free testing of wheat for the vomitoxin is available at The Star of the West Mill in Churchville, near Rochester.  If scab is present in a wheat field, experts recommend turning up fans on the combine to blow out small, lightweight kernels, and taking measures to clean the wheat.



There will soon be another tool in the FHB IPM toolbox!  A new variety of soft white winter wheat called Jensen has been developed in the Cornell Small Grains Breeding Program, led by Mark Sorrells.  Jensen is more resistant to FHB than currently available soft white winter wheat varieties, and should be widely available for fall 2008 plantings.

Wheat Harvest - Preparing Bins to Avoid Pest Problems

Keith Waldron
NYS IPM

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You have nurtured the wheat crop since planting, watched closely for nutritional needs and pests, tuned in the weather channel and kept tabs on the commodity exchange. Now that wheat heads are beginning to lighten in color it won't be too long before it's harvest time. Will your storage bins be ready? Most producers are quite familiar with the in-ground aspects of wheat production. To maintain the profits a good yield can bring, make and follow a plan to protect the grain while in storage. 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 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 of the 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 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.

The following sanitation practices are recommended for managing empty storage bins.
* Clean harvest and transportation machines before harvest.
* Repair all grain handling equipment before harvest and keep it in good condition.
* Seal unloading auger, auger tube opening, and side door openings before harvest
* 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.
* Remove any spilled grain outside the storage structure.
* Mow / remove weeds at least 10 feet around the bins.
* Check and clean or replace rodent traps.
* Check the integrity of 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, four to six weeks prior to harvest, to kill any insects that were not removed during cleaning and those that migrate into the bin.
* Establish a written sanitation schedule, keep appropriate records

Bin Sealing
Roof leaks commonly lead to columns of spoiled grain. Check for these leaks by looking for light coming into the bin. Moisture coming into the bin through the seal between the bin and concrete will cause spoilage around the perimeter of the bin at the base. Check the seal since sealants do deteriorate. 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.

In addition, improved insect kill (efficacy), tighter sealed structures require lower dosage rates, which reduce the cost of future fumigations and cover the cost for the sealing materials and labor.
When clean grain is transferred into a clean, sanitized structure with base and sidewalls well sealed, the main insect infestation and population growth should be on the grain surface in the structure headspace. Permanently sealing all non-functional base, sidewall and roof openings is the first priority of sealing storages. The second sealing priority is to seal functional openings at all times during the year when the component is not being 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 Purdue's Stored Product Pest factsheet.

Sampling for Potato Leafhopper in Alfalfa

Ken Wise
NYS IPM

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Scouting alfalfa fields is the key to early detection of potato leafhopper infestations. Use a 15-inch diameter sweep net to determine the potential risk a potato leafhopper infestation may pose to your alfalfa. Scouting for potato leafhopper starts after the first cutting of alfalfa (about the first part of June) till the first fall frost. You will want to use a potato leafhopper sequential sampling plan to determine if an infestation requires management or not. The first thing to do is determine the height of your alfalfa. Smaller plants are more vulnerable to potato leafhopper; thus there are different action thresholds for different heights of alfalfa. The second thing you will need to know is how to sample for potato leafhopper. A sample consists of a set of 10 sweeps of the net. A sweep is one pass in front of you as you walk through the alfalfa. The return swing is counted as another sweep. Sequential sampling reduces the time spent in each field and tells you whether to treat (management action) or not treat (no management action). Sequential sampling is particularly helpful in minimizing time required to make a management decision in situations where PLH populations are very high or very low. Use the following chart to determine potato leafhopper infestation levels.

N= No management needed at this timep">

T= Management needed as soon as possible 

Write down the number of potato leafhoppers for each sample taken on the card. Add each sample to the next, keeping a running total of potato leafhoppers. You will need to take at least 3 samples using the sequential sampling method. On the sequential sampling card “N” is defined as no treatment (no management) needed at this time and “T” is defined as treatment (management) needed within in a week. If the sample is smaller than the “N” number stop and scout 7 days later. If the number of leafhoppers is larger than the “T” number then management action needs to be taken within a week. If the number of potato leafhoppers fall between “N” and “T” then continue and take the next sample till a decision can be determined. Check out our online PLH Sampling Guide for a printable version of the sequential sampling chart.

Soybean Rust Update

Gary Bergstrom
Cornell Univeristy Plant Pathology

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NYS 2007 Asian Soybean Rust Status

Most of the twenty sentinel plots have been planted in the following New York counties:  Cayuga, Chautauqua, Chemung,Chenango, Columbia, Cortland,Jefferson, Montgomery, Oneida,Onondaga, Ontario, Orleans,Oswego, St. Lawrence, Seneca, Steuben, Suffolk, Wayne, and Wyoming. Scouting in these plots should begin in the next week. Updates on scouting efforts in these sentinel plots will be posted weekly on the NY State Soybean Rust Information Center.

Scouting for soybean rust has intensified nationally with most of the sentinel plots being monitored regularly throughout most of the soybean growing states, and north to Canada. On June 14th, a commercial field in Hidalgo County, Texas was confirmed to have soybean rust. Soybean rust was found on volunteer soybeans in this county earlier this year as well as last year on late planted soybeans. This is the second detection of rust on soybean this year in Texas. Soybean rust has also been detected on kudzu in 10 counties in Florida and in five counties in each of Georgia and Alabama, two counties in Louisiana and one in Texas. (Updated June 21, 2007 )

http://www.ppath.cornell.edu/soybeanrustny/

NY Soybean Aphid Update

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(updated: 06/20/07)

From: NY section of the United States Soybean Rust Soybean Aphid Commentary.

New York State Agricultural Statistics estimates 210, 000 acres of soybeans were planted in NY this season. Most soybeans are currently in the early stages of emergence between the unifoliate and V3 leaf stage.

Soybean aphids (SBA's) were reported last week (6/11-13/07) by Cornell cooperative extension personnel in south central and central NY. Where present, most fields had 0-3 SBA's per plant. A few central NY fields, however, in Ontario and Wayne Counties had counts averaging 25 per plant with as many as 100 per plant on unifoliate soybean seedlings. Reports this week indicate soybean aphid populations have been also been observed on young soybean seedlings in Cayuga (central and Columbia (eastern) NY. The Columbia county site found an average of 20 SBA’s per plant.

Low numbers of natural enemies such as lady bird beetles (Coccinellid spp) have been observed. http://www.sbrusa.net/

Clipboard Checklist

Keith Waldron
NYS IPM

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General:
* Maintain crop records by field, including variety, planting date, pesticides used, nutrient inputs including manure, etc.
* Watch for early season weed escapes, any patches of herbicide resistant weeds?
* Storage areas cleaned and ready to accept upcoming hay harvest?

Corn:
* Determine plant populations, make notes on emergence, drought, and other problems
* Check for cutworm, armyworm, leaf blights, slugs, bird and deer damage
* Monitor for weeds, note presence of "who", "how many" and "where"
* Adjust post emergence weed control actions as appropriate

Small Grains:
* Monitor winter grains for crop growth stage, insect and disease problems
        - evaluate crop for adequate stand and plant vigor
        - evaluate crop for Fusarium head blight (Scab) and other grain head diseases
* Check, clean, prepare storage bins to accept upcoming harvest?
* Mow around storage bins to remove rodent habitat, remove spilled grain
* Clean grain handling equipment (conveyors, wagons, trucks, combines, elevators, etc.) for signs of leftover grain - remove potential sources of stored grain insect infestations.

Alfalfa & Hay:
* Monitor alfalfa seedings for weeds, potato leafhopper and diseases.
* Check established alfalfa stands for potato leafhopper, weed and disease problems

Soybeans:

* Initial stand assessment: plant populations, seedling diseases

* Begin monitoring fields for presence of soybean aphids, and other insects, including natural enemies such as lady bird beetles.

* Check droughty fields for presence of spider mites

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
* Begin fly monitoring: install "3X5" index card fly speck monitoring cards through out barn
* Order fly management materials: fly tapes, insecticide baits, natural enemies (parasitoids)

Dairy Livestock Pasture Fly Management:

* Monitor animals for face, horn, and stable fly populations

* Check feed troughs, around waterers for signs of stable fly breeding.

* Consider use of traps if horse and stable fly populations are a problem

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

Growing Degree Days in NYS

Ken Wise
NYS IPM

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CURRENT Accumulated Growing degree days (48F Base) as of March 1 -  June 19, 2007

Location     

Base 48 F     

Base 50 F 

Batavia 

823 

716 

Chazy

733

 640

Clifton Park

1101

 981

Geneva

 869

 758

Ithaca

 800

 697

Prattsburg

 713

 618

 

Source: http://newa.nysaes.cornell.edu/base5005.htm

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

 

Stage or Event     

Accumulated growing degree days 

Egg Hatch

 280

Instar 1 

 315

Instar 2

 395

Instar 3

 470

Instar 4

 550

Cocooning

 600

Pupa

 725

Adult Emergence

 815

(Note: for alfalfa weevil predictions use Base Temp of 48F)

Upcoming Events


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SEED GROWERS FIELD DAY

NYSIP Foundation Seed Barn
Thursday, July 5, 2007
Ithaca, NY (761 Dryden Road, Route 366)
Registration and Coffee at 9:00 AM
Tour Begins at 9:30 AM

WEED SCIENCE FIELD DAYS

Valatie Research Farm – July 6
(Stage Farm Road just off Route 9, North of Valatie)
Registration and Coffee at 9:00 AM
Tour Begins at 9:30 AM to 12 Noon
(Field Crops)

Robert B. Musgrave Research Farm- July 11
(Popular Ridge Road, connects 90 and 34B)
11:00 am to 1:00 pm-Chicken BBQ
1:00 pm Registration
1:30 pm to 5:00 pm Tour
(Field Crops)

H.C. Thompson Research Farm- July 12
Freeville, NY 10 miles north of Ithaca, Fall Creek Road Rt. 366 extension)
8:00 am Registration ($8 Informational Packet)
8:30 am to Noon-Vegetable Weed Control

AURORA FIELD DAY

ROBERT MUSGRAVE RESEARCH FARM
Thursday July 26, 2007
Poplar Ridge Road, Aurora, NY (connects 90 and 34B)
Coffee at 9:30 AM
Tour Plots 10 AM to 3 PM

Contact Information


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Julie Dennis: Western NYS IPM Area Educator, Livestock and Field Crops
Phone: (315) 331-8415
Fax: (315) 331-8411
Email: js38@cornell.edu

Keith Waldron: NYS Livestock and Field Crops IPM Coordinator
Phone: (315) 787 - 2432
Fax: (315) 787-2360
Email: jkw5@cornell.edu

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