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Weekly Field Crops Pest Report 2012

May 17, 2012, Volume 11 Number 5

  1. View from the Field
  2. Weather Outlook
  3. Weeds of the Weed: Garlic Mustard and Common Comfrey
  4. Growing Degree Days
  5. Clipboard Checklist
  6. Mark Your Calendars
  7. Contact Information

View from the Field

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While scouting the Cornell Research Farm in Valatie I found white and deformed head of triticale. These symptoms indicate frost damage. The damage most likely occurred while the plant was still in the boot stage.

frost damage in triticale

Frost damage on triticale

In a field of oats that borders the farm in Valatie I found my first cereal leaf beetle larvae in almost 12 years in Eastern NY.  I only found 2 larvae along the edge of the field. The adults are 3/16 inch long with a metallic bluish-black head and wing covers. Eggs can be found on the upper surface of the leaves near the midrib. Eggs are elongate, yellow to brown, about 1/16 of an inch long, and are laid in chains of two or three. Small, black slug-like larvae emerge from eggs and reach about a ¼ inch. Larvae feed on the leaf surface, leaving a long narrow white strip between the veins. Cereal leaf beetle is more of a problem in oats but can reach threshold levels in wheat.  The economic threshold for cereal leaf beetle is 3 or more eggs and larvae per stem before the boot stage of oat, or 1 or more larvae per flag leaf after the boot stage. Check 30 stems distributed throughout a field to determine if the fields are at an action threshold.

cereal leaf beetle larva feeding

Cereal leaf beetle larva feeding

Alfalfa weevil tip feeding ranged from 80 to 100 percent in fields at the Valatie farm. The threshold for 1st cutting is 40 percent tip feeding. While these fields are mixed alfalfa/clover and older stands of alfalfa, they most likely are losing yield.

alfalfa weevil tip feeding

Tip feeding with alfalfa weevil in tip

Keith Waldron made field observations in the Finger Lakes area this week. He found alfalfa weevil larvae in the 2nd and 3rd instars. He examined buckthorn in hedgerows at NYSAES farm in Geneva. There were no sign of soybean aphids and minimal presence of oat crown rust pustules on buckthorn leaves. Remember that buckthorn is the winter host for soybean aphid and an alternate host for oat crown rust pustules.
While walking ground to be planted to corn or soybeans, he kept an eye on weed populations. Of particular interest were perennial species, and any concentrations of weeds such as common lambsquarters, smooth pigweed, common ragweed, and common groundsel. These can indicate presence of potential triazine herbicide resistance issues.  Keith also monitored reduced tillage fields and fields with crop residue for slug and snail activity. He checked under leaves of large broadleaf weeds such as burdock for slug daytime hideouts. He also found 2 brown marmorated stink bugs (BMSB) in Geneva, NY. He also found 2 brown marmorated stink bugs. BMSB has a broad host range and is on our corn and soybean crop watch list. It’s presence is of local interest, but is not of immediate economic concern.

Black Cutworm and Armyworm Update

Indiana is still reporting high captures of black cutworm and true armyworm moths. But Penn State has still not yet detected a significant flight of black cutworm or true armyworm moths. It is important to continue checking for feeding in the fields. So far, I’ve not found any black cutworm and true armyworms in the few corn fields I’ve checked in Eastern NY.

Weather Outlook

April 26, 2012
Jessica Rennells, Northeast Region Climate Center, Cornell University

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Last week temperatures ranged from zero to six degrees above normal.  Precipitation amounts ranged from just a trace up to two inches.  The base 50 growing degree-days ranged from 25 to 75.

High pressure will be in control for the next several days bringing sunny skies and clear nights.

Today will be sunny with temperatures throughout the 60s.  Lows will range from the mid 30s to mid 40s.  A frost advisory has been issued for several counties, as freezing temperatures are possible in the normally colder deeper valleys.  A freeze warning has been issued for areas in the Northern Plateau and St Lawrence Valley.

Friday will be sunny with highs in the upper 60s to mid 70s.  Overnight temperatures will be in the mid to upper 40s.

Saturday we’ll have continued with temperatures in the mid 70s to low 80s.  Lows will be in the low to mid 50s.

Sunday will be partly sunny with highs in the upper 70s and low 80s.  Overnight temperatures will be throughout the 50s.

Monday will be mostly sunny with highs still remaining warm in the mid 70s to low 80s.  Lows will be throughout the 50s.  There is a chance for precipitation late Monday.

Tuesday will be mostly sunny with temperatures in the mid to upper 70s and a possibility for scattered showers and thunderstorms.  Lows will be in the mid to upper 50s.

Wednesday will be in the mid to upper 70s with some scattered showers and thunderstorms possible.  Lows again will be in the mid to upper 50’s.

The five-day precipitation amounts will only be up to a tenth of an inch. The 8-14 day out look is showing above normal temperatures and below normal precipitation.

National Weather Service Climate Prediction Service Maps of 8-14 day outlooks

National Weather Service Eastern Region Headquarters watch/warnings map

NRCC Drought Page which features the US Drought Monitor map (updated every Thursday)

Weeds of the Weed: Garlic Mustard and Common Comfrey


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This week there were discussions about 2 different kinds of weeds garlic mustard and comfrey. Garlic mustard is an invasive species found in field margins, pasture edges, hedgerows and especially wooded areas. This is a cool season biannual herb. It was introduced from Europe with early American settlers. They thought it had medicinal properties. The weed can out-compete other native or desirable plants. For more information download the Garlic Mustard Information pamphlet (1.22Mb pdf file) from the Wisconsin DNR website.

Comfrey has been found along the edges of hayfields and seems to cause problems with harvest equipment. The plant is large and out-competes the forage around it. This perennial herb that was introduced from Europe as a medicinal plant. The weed can adapt too many habitats: the edges of hayfields and pastures, ditches and disturbed ground. It likes good soil with lime, moisture and shade. It grows 2 to 3 feet tall and the leaves on the lower part of the plant can be 12 inches long. Interestingly, comfrey is popular for medicinal purposes but has toxic alkaloids—more so in the roots.

Ohio Perennial and Biannual Weed Guide: Common Comfrey

Growing Degree Days

Ken Wise, NYS IPM

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CURRENT Accumulated Growing degree days (48F Base):

March 1 - May 2, 2011

Base 48 F
Base 50 F
*Indicates missing data
source: NEWA's Degree Day data page

Alfalfa Weevil Prediction Model
A website at NEWA can predict alfalfa weevil development in your area. Just select a weather station near you and it will give you the AW degree days.

Clipboard Checklist

Keith Waldron

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*Maintain crop records by field, including variety, planting date, pesticides used, nutrient inputs including manure, etc.
*Minimize field-to-field movement of soil and crop debris on equipment, particularly from fields with known pest problems such as white mold and Phytophthora.
*Evaluate early season weed pressure: winter annuals? perennials?  grasses? broadleaves? weed / crop growth stage?

*Evaluate legume stands for winter damage, determine average alfalfa stand count, adjust crop plans if necessary
*Monitor for alfalfa weevil. Monitor for alfalfa snout beetle in Oswego, Jefferson, Cayuga, Wayne, Lewis, St. Lawrence, Clinton, Essex, and Franklin counties.
*Monitor new seedings for Pythium blight and Phytopthora Root Rot.

Small Grains:
*Monitor winter grain fields for growth stage, number of tillers
*Check stands for soilborne virus diseases, Wheat spindle streak mosaic and Soilborne wheat mosaic and powdery mildew symptoms, cereal leaf beetle, weed escapes, goose damage

*Prepare land and plant corn as soon as conditions allow
*Pre-plant weed evaluation, timing cultivation, and/or pre-plant weed management
*Monitor early planted corn for emergence issues

Check crop growth, invasive species, plants harmful to livestock
*Review/Plan rotation system

*Check nozzles, pumps, etc., recalibrate pesticide application equipment before use.
*Calibrate planting equipment and manure spreaders. Maintain records on seeding application rates applied per field
*Carry appropriate / necessary NYS DEC and EPA required documents: (pesticide applicators license, pesticide labels, MSDS sheets, etc.) with application equipment

* Check stored grain bins for temperature, moisture and signs of mold and insects. Aerate, core, transfer grain or treat as necessary
*Check forage allocation and anticipate feed program adjustments as forages from previous year are used up

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 SMALL GRAINS MANAGEMENT FIELD DAY, Musgrave Research Farm, 1256 Poplar Ridge Road, Aurora, NY, Thursday June 7, 2012. The program will run from 10:00am-12:00 noon. Registration begins at 9:30 am.
An educational program of the Integrated Field Crop, Soil, and Pest Management Program Work Team in conjunction with Cornell Cooperative Extension will host the Small Grains Management Field Day with research demonstrations and presentations of interest to the local farming community. DEC and CCA credits will be available.  For more information, please contact Mary McKellar 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