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Weekly Field Crops Pest Report 2011

June 3, 2011, Volume 10 Number 5

  1. View from the Field
  2. Weather Outlook
  3. Fusarium Head Blight Commentary
  4. How to Recognize Scab (Fusarium head blight) on Wheat
  5. Cornell's Plant Disease Diagnostic Clinic – New Website
  6. Growing Degree Days
  7. April & May Showers Break Records
  8. Clipboard Checklist
  9. Mark Your Calendars
  10. Contact Information

View from the Field

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Keith Severson in Cayuga County reports the first signs of potato leafhopper (PLH) of the season.  While we monitor PLH on alfalfa this insect pest has about 150 host plants. This lime-green adult insect about 1/8 inches long.

potato leafhopper

They ride the storms that come from the south. Since we have had several storms already this season it is not surprising they have arrived. This insect is a very strong flyer and can move from plant to plant with ease. Each adult female can lay 2-3 eggs per day. Young PLH, called nymphs, looks much like the adult but are smaller and are bright yellow-green. Both nymphs and adults have needle-like mouthparts they use to pierce the plant and suck juices out. While sucking the juices out they replace it with toxic saliva. This is what causes the damage to the plant. If you notice a V-shaped yellowing on the tips of the leaves, stunting or purpling of leaves it's too late. Potato leafhopper has likely reduced plant protein by 5% and yield by about 0.10 - 0.25 ton per acre pre cutting. New seedings are at higher risk to potato leafhopper damage. Crop stress from this insect can impact production this season as well as affect production potential for subsequent years. The key is to scout fields before the damage has already occurred.
While at the Cornell University's Small Grains Management Field Day (June 2) a grower brought some wheat that was infected with leaf rust. Leaf rust can be a very devastating disease of wheat. The disease travels on storms for the south and will infect wheat from late April through June.
Leaf rust can be easily identified because the rust lesions are vivid orange in color, but are small and circular. Leaf rust occurs on the surface of leaves and rarely infects the stems. There are 2 other rust diseases that do infect wheat stems: stem rust and stripe rust.  Leaf rust can develop very rapidly so it should be treated as soon as possible.  Leaf rust is favored by warm and humid weather with thunderstorms in June. The rust is disseminated on by winds which carry the airborne spores great distances. The ideal temperature for the disease to develop is between 600 and 800 F.  When monitoring wheat rust assess upper three leaves for symptoms and signs of leaf rust in early to mid-May, before flag leaf emergence. Look at 20 different plants in 10 areas of the field. If disease (any amount) is observed on approximately 50 percent of main tillers, averaged across the field, a spray should be considered now.

There are reports that black cutworm populations are over threshold in several corn fields in the upper Hudson Valley and central NY. The moths travel on storms from the south and southwest. They lay eggs on grass weeds in fields. Because of the large number of adult cutworm moths caught in south and southwest this season you need to keep a keen eye on your corn fields. Especially corn with excess grassy weeds and no-tillage/conservation tilled fields. Once the weeds are sprayed the cutworm will switch to feeding on the corn.
As stated last week Mike Stanyard reported that cereal leaf beetle were at very high levels in some wheat fields. Keep monitoring wheat and oats for cereal leaf beetle.

Weather Outlook

June 1 , 2011

Jessica Rennells, Northeast Region Climate Center, Cornell University

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The whole state has seen above normal temperatures ranging from 3 to over 9 degrees above normal.  Some record highs were broken yesterday.  Precipitation has ranged from less than half an inch in the Hudson Valley to over two inches in western & central NY and parts of northeast NY.  These high rain amounts are associated with the strong storms we had.  The base 50 growing degree days have ranged from 75 to over 125.
Today (6.1.11) we'll have continued above normal temperatures in the mid 70's to near 90 with a chance for showers and thunderstorms through early afternoon as a cold front moves through.  Overnight temperatures will be cooler in the low 40's to low 50's. Thursday will be cooler and dry with temperatures in the upper 50's to low 70's.  Lows will be mostly in the 40's but northern NY will see some 30's and possible frost. Friday's highs will be in the mid 60's to low 70's.  Lows will be in the mid to upper 40's. Saturday temperatures will be throughout the 70's with a chance for showers in western NY as a warm front enters the state.  Lows will be in the mid 40's to mid 50's. Sunday highs will be throughout the 70's with rain possible as the frontal systems move through the state.  Lows will be in the upper 50's and low 60's. Monday highs will again be throughout the 70's with a slight chance of showers.  Lows will be in the mid to upper 50's. Tuesday's highs will be in the 70's with some showers possible.  Lows will be in the 50's.
The five day precipitation amounts will finally be lower, ranging from a tenth to half an inch.   The 8-14 day outlook is showing  above normal temperatures and precipitation for most of the state.  
The one month outlook is showing equal chances for above or below normal precipitation.

Fusarium Head Blight Commentary

Gary Bergstrom, Department of Plant Pathology and Plant-Microbe Biology
Cornell University

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Application of triazole fungicides (Caramba, Prosaro, Proline, or generic tebuconazole) for suppression of Fusarium head blight (FHB) is best timed for the beginning of flowering (emergence of yellow anthers). Winter wheat development in New York State currently ranges from boot (Feekes 10) to beginning of flowering (Feekes 10.5.1) stages. Low to moderate levels of powdery mildew and fungal leaf blotches have been observed. Most wheat fields will begin flowering this weekend into next week, so consult the risk prediction map tool frequently over the next several days. Cooler, drier conditions, less conducive for Fusarium infection, are expected for the next few days. We will update this commentary before the weekend.

Fusarium head blight map risk assessment tool 2011

As the winter wheat crop approaches flowering, growers and crop consultants are urged to consult frequently the map-based risk assessment tool that utilizes regional weather parameters to establish the general level of risk for severe infection (at crop flowering) of Fusarium head blight.  This is suggested as just one available tool to utilize in decisions concerning fungicide application at flowering.  Local factors of crop history, microclimate, and wheat variety are also important in fungicide decisions. 

How to Recognize Scab (Fusarium head blight) on Wheat

Ken Wise, NYSIPM

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One of the most devastating diseases of wheat is Scab or also called "Fusarium head blight." This disease infects the grain head at flowering. The disease builds up in corn, wheat and other grain residues. During the day the spores are carried up into the atmosphere and at night settle out across the landscape. If it rains at flowering and spores are present there is a good chance the grain will become infected with the disease. The first symptoms of Fusarium head blight occur shortly after flowering. Diseased wheat heads exhibit premature bleaching as the pathogen progresses.  One or more spikelets located in the top, middle, or bottom of the head may be bleached. Over time, the premature bleaching of the spikelets may progress throughout the entire head. If the environment is warm and moist, aggregations of light pink/salmon colored spores may appear on the rachis and glumes of individual spikelets. Later in the season, bluish- black spherical bodies may appear on the surface of affected spikelets. As symptoms progress, the fungus colonizes the developing grain causing it to shrink and wrinkle inside the head. Often, the infected kernels have a rough, wilted appearance, ranging in color from pink, soft-gray, to light-brown.

fusarium head blight disease

Figure 1: Symptoms of Fusarium head blight (photo taken by Dr. Gary Bergstrom)

For more information regarding Fusarium head blight management see Managing Diseases of Small Grain Cereals.

Fusarium head blight map risk assessment tool 2011

Cornell's Plant Disease Diagnostic Clinic – New Website

Gary Bergstrom, Department of Plant Pathology and Plant-Microbe Biology
Cornell University

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The Cornell University Plant Disease Diagnostic Clinic is designed to provide plant disease diagnostic services for anyone from home owners to commercial growers. The clinic provides accurate plant disease diagnosis, quick turnaround time, professional services, and up-to-date control recommendations. Services include analysis of plant material and soil for bacterial, fungal, viral, and nematode pathogens. The Plant Disease Diagnostic Clinic is a facility of the Department of Plant Pathology and Plant-Microbe Biology at Cornell University. The Clinic promotes a "Test, Don't Guess" attitude. This is because we feel that knowing the pest affecting your plants and crops prior to treatment is essential for the best chances of recovery. The "Test; Don't Guess" policy allows for the appropriate selection and efficient use of control methods. The site includes forms and instructions for sample submission and useful links.

Growing Degree Days

Ken Wise,

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CURRENT Accumulated Growing degree days (48F Base):

March 1 - May 25, 2011

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

April & May Showers Break Records

Jessica Rennells, Northeast Region Climate Center, Cornell University

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April and May combined have been the wettest on record for several Northeast cities, most of which have had over a foot of rain.  While areas in the Mid Atlantic states are having abnormally dry conditions, most of the Northeast has had above normal precipitation and flooding issues.  A repeated pattern of frontal systems bringing rain and strong thunderstorms producing heavy rainfall has contributed to these record breaking months.

April 1 – May 31 Rainfall Rankings (inches)

Name Rank
Apr 1 - May 31
Amount Wettest
Apr 1 - May 31
Huntington, WV 1 18.23 14.01 2003
Burlington, VT 1 16.55 12.86 1983
Williamsport, PA 1 16.48 12.04 1998
Binghamton, NY 1 16.03 13.51 2000
Erie, PA 1 14.92 14.86 1947
Harrisburg, PA 1 14.8 13.47 1889
Buffalo, NY 1 13.78 11.3 1990
Ithaca, NY 1 13.58 12.18 1894
Rochester, NY 1 10.61 10.26 1943
Syracuse, NY 3 12.43 15.53 1976
Scranton, PA 4 10.92 13.63 1947
Charleston, WV 5 11.54 13.05 2004
Pittsburgh 10 9.71 13.91 1901
Newark, NJ 12 10.64 16.58 1984
Central Park, NY 16 10.46 16.36 1984
Philadelphia, PA 51 7.2 15.15 1983
Boston, MA 55 7.27 18.63 1954
Washington, DC 149 3.72 19.82 1889

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.
*Walk fields to check crop condition, growth, and emergence. Look for signs of vertebrate pests (birds, gound hogs, deer, etc.).
*Watch for early season weeds: winter annuals: chickweed, henbit, purple deadnettle, field penny cress, shepherd's purse; annuals: giant ragweed, lambsquarters, Pennsylvania smartweed, dandelion, bedstraw.
*Mow around farm buildings to minimize rodent and other pest habitat
Alfalfa and Grass Hay:
*Monitor alfalfa for crop condition, alfalfa weevil, potato leafhopper, foliar, systemic and crown rot diseases.
*Evaluate alfalfa seedings for weeds, insects (potato leafhopper) & diseases.
*Monitor alfalfa and grass stands to determine optimal harvest date.
Watch windrow areas of harvested alfalfa for signs of alfalfa weevil feeding
Small Grains:
*Monitor winter grain fields for crop growth stage, signs and symptoms of diseases, weed pressure, insects (cereal leaf beetle) goose damage
*Monitor winter wheat for foliar diseases, potential for Fusarium Head Blight
Field Corn:
*Finish corn planting
*Using a Bt hybrid? Have a refuge plan?
*Post emergence: Determine corn plant populations, monitor for emergence problems, weeds, noting presence of "who", "how many" and "where"
* Corn rootworm eggs hatch about the time of first fireflies sightings
* Early season corn pests: seedling blights, seed corn maggot, white grub, wireworm, black cutworm, slugs, birds
*Adjust post emergence weed control actions

*Pre-plant field assessment and weed evaluation
*Post emergence: Determine plant populations, monitor for germination and emergence problems, monitor for weeds, noting presence of "who", "how many" and "where"
*Check and mend fences as needed.
*Check crop growth
*Check for presence of undesirable plant species harmful to livestock.
*Review/Plan rotation system
*Arrange for custom weed control or check your own application or cultivator equipment for readiness or need for repairs.
*Check nozzles, pumps, etc., recalibrate pesticide application equipment regularly before use.
*Calibrate planting equipment - maintain records on crop planting rate per field
*Calibrate manure spreaders - maintain records on amount spread per field
*Check forage allocation and anticipate feed program adjustments as forages from previous year are used up
*Plan where forages should be stored for optimum allocation next feeding season

Cattle on Pasture:
*Monitor animals for presence of face flies, horn flies and stable flies. Action guidelines: face flies (average 10 per animal face), horn flies (average 50 / dairy, 200 / beef cattle per animal side), stable flies average 10 per animal  (all four legs)
*Check feed bunk / water source locations for signs of stable fly breeding (moist undisturbed organic matter – spilled feed, round bales, etc.), minimize source of moist organic matter i.e. fly breeding areas in barn and in adjacent animal loafing yard
*Check paddocks for forage quality / quantity, rotate as appropriate
*Check paddocks for vegetation poisonous to livestock
*Consider use of fly traps to help reduce deer, horse and stable fly populations
Dairy Cattle Barn Fly Management:
*Monitor animals and barn area for house fly, stable fly and other pest management needs including presence of rodents and birds.
*Check facilities for favorable fly breeding conditions: (organic matter + moisture): leaks in watering systems, roof gutters for leaks and potential overspill, drainage,
*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 * Continue fly monitoring: install "3X5" index card fly speck monitoring cards throughout barn
*Use, replenish, replace fly management materials: sticky fly tapes/ribbons, insecticide baits, natural enemies (parasitoids), fly population monitoring (3 x 5) spot cards
*Consider purchase and release of Muscidifurax raptor and/or M. raptorellus natural enemies of house and stable fly pupae.


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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Cornell University's Aurora Farm Field Day, Musgrave Research Farm, 1256 Poplar Ridge Road, Aurora, NY, Thursday July 14, 2011. 10:00am-3:00pm, free registration begins at 9:00.
Aurora Farm Field Day will highlight research demonstrations and presentations of interest to the local farming community.  Details on program topics forthcoming.  

Cornell University's Weed Days – Wednesday, July 13th
Morning program at the Thompson Vegetable Farm in Freeville and afternoon program at the Musgrave Research Farm in Aurora. DEC and CCA credits available. 
For more information regarding these meetings, please contact Larissa Smith at or 607-255-2177

Contact Information

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

Ken Wise: Eastern NYS IPM Area Educator: Field Crops and Livestock
Phone: (518) 434-1690
Fax: (518) 426-3316