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Weekly Field Crops Pest Report 2012

June 1, 2012, Volume 11 Number 7

  1. View from the Field
  2. Weather Outlook
  3. New York State Armyworm Alert!
  4. Fusarium Head Blight on Wheat Update
  5. Growing Degree Days
  6. Clipboard Checklist
  7. Mark Your Calendars
  8. Contact Information

View from the Field

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Armyworm was active in western and eastern NY this week.
Nathan Herendeen (WNY Crop Management Association)reports true armyworm at threshold levels in winter wheat in western NY. The worms were about one inch in length. He reports that the levels are the highest in several years. A number of fields have been treated with an insecticide. Aaron Gabriel (CCE) reports finding true armyworm in grass hay in several fields Washington and Schenectady counties. He states that the larvae are still small. He speculates that armyworm might be wide spread and urges growers to get out and look at their fields before they get larger.   

True armyworms are pests of grasses. The most common infestation sites for true armyworm larvae include dense fields of grasses, including wheat and other cereals, grassy forages, fields with rye cover crops and corn.  Good grass control within and along field margins helps reduce the risk of infestations. Growers are urged to check fields now!

More about Armyworm in article below.

Also this week. Alfalfa weevil populations are still active but populations appear to be maturing. Alfalfa weevil damage is more obvious in mixed and thinning alfalfa stands. There are first sightings of soybean aphids in western NY.  Wet weather favorable conditions for slug and snail populations and associated injury in soybeans and corn. Michigan has caught their first Western Bean Cutworm moths of the year.

Weather Outlook

May 31, 2012
Jessica Rennells, Northeast Region Climate Center, Cornell University

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Last week temperatures ranged from 9 to 12 degrees above normal for most of the state.  Areas of Oswego, Onondaga, and Cayuga counties were over 12 degrees above normal, while areas in the St Lawrence Valley were 6 to 9 degrees above normal.  Precipitation amounts ranged from just a trace to an inch for most of the state, isolated areas had up to 2 inches due to storms earlier in the week.  The base 50 growing degree-days ranged from 100 to 150. Today (5.31.12) will be sunny with temperatures closer to normal. Western NY will see mid 60’s, increasing across the state to upper 70’s along the Hudson Valley.  Overnight temperatures will be in the mid to upper 40’s. Friday will be mostly cloudy and rainy with highs in the 70’s.  A low-pressure system will move across the state on Friday and into the evening brining showers, heavy at times and thunderstorms are possible.  Precipitation totals are expected to be 1-1 1/2 inches.  Lows will be in the 50’s. Saturday will be cloudy with showers possible throughout the day and highs in the mid to upper 60’s.  Lows will be in the upper 40’s and low 50’s. Sunday will cloudy with possible showers throughout the day but peaking in the afternoon, highs will be in the upper 60’s and low 70’s.  Overnight temperatures will be in the low 50’s. Monday will be partly sunny with a chance for showers and temperatures in the 70’s.  Lows will be in the mid to upper 50’s. Tuesday’s temperatures will be in the upper 60’s and low 70’s with partly sunny skies.  Lows will be in the 50’s. Wednesday will be in the mid 60’s to low 70’s with overnight temperatures in the low to mid 50’s.

The five-day precipitation amounts will range from 1.5 to over 2 inches. The 8-14 day outlook is showing above normal temperatures for all but the lower Hudson Valley and normal precipitation for most of the state (Chautauqua county is in below normal precipitation; lower Hudson Valley is in above normal precipitation).  The current Drought Monitor now has areas of western NY and the southern Hudson Valley and Catskills as abnormally dry, though Friday’s rain should help to alleviate this.

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)

New York State Armyworm Alert!


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True Armyworm infestations have been reported this week in eastern and western NY.
As mentioned in the View from the field. GET OUT AND LOOK NOW!

It is important to detect armyworm areas early, while larvae are still small, since large larvae do most of the feeding and quickly destroy whole stands of corn, grasses and small grains. Because armyworm feeds at night look for chewed leaves, cut stems, lodged plants, pellet-like frass on the ground, and larvae hidden under plant canopy and surface residue. You will need to be aware that armyworms can move from field to field every quickly. If there are sufficient numbers and damage is present, an insecticide could be justified. Larger armyworm larvae, greater than 1 inch long, are much more difficult to control. These large larvae are more tolerant of insecticides, reducing the effectiveness and economic viability of this option. REMEMBER… if you have an infestation in a mixed stand true armyworm, alfalfa and the grass ALL NEED to be on the LABEL!!!

True armyworm larvae appear smooth cylindrical pale green too brownish when they are still small. Mature larvae are smooth and marked with two orange, white-bordered strips on each side. True armyworm ranges in size from 1/8 inch to 1 .5 inches long.


Economic Threshold Guidelines For True Armyworm

Corn – Midwestern extension specialists recommend treating seedling stage corn when 25 percent or more of the seedling corn plants are damaged and true armyworm larvae are still present. For whorl-stage corn, apply an insecticide only if most plants show damage and about three larvae per plant are found.  Note: control can be challenging if caterpillars are greater than one-inch long.

Wheat – 3 to 5 or more larvae square foot, larvae less than 1.25 inches and not parasitized, watch for flag leaf reduction or if grain heads clipped off - yield losses, a spray before soft dough to save the remaining 3 upper leaves is generally beneficial since these tissues are still important to grain filling.

Grass pastures - Midwestern extension guidelines indicate  insecticide treatments are justified when four or more non-parasitized, half-grown or larger larvae are present per square foot. No specific guidelines are available in NY, need for treatment based on the level of damage observed in relation to the expected value of grass harvest. REMEMBER… if you have a true armyworm infestation in a mixed alfalfa – grass stand, alfalfa and grass BOTH NEED to be on the LABEL!!!

Identification Resources:
Armyworm as a pest of Field Corn

Armyworm on Wheat

Common (True) Armyworm

Fall Armyworm

Fusarium Head Blight on Wheat Update

Gary Berstrom-Plant Pathology Cornell University

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Winter wheat in New York is generally a week or more past the initiation of flowering, and fungicide application should no longer be considered.  Some fields may be harvested within 30 days, the harvest restriction interval for triazole fungicides.  According to the FHB Risk Tool, the risk of FHB resulting from infection at flowering in May was low across the state. The first leaf rust of the season was observed this week in Orleans Co.  Powdery mildew and fungal leaf blotches are present but generally at low levels. Several fields in the western counties along Lake Ontario had armyworm above threshold levels and were sprayed with insecticide.  Overall, the New York winter wheat crop looks excellent.

Growing Degree Days

Ken Wise, NYS IPM

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CURRENT Accumulated Growing degree days (48F Base):

March 1 - May 30, 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.

Degree Days for Peak (50%) Occurrence of Alfalfa Weevil Stages
Stage or Event (Degree Days - Base 48): eggs hatch (280 GDD), instar 1 (315 GDD), instar 2 (395 GDD), instar 3 (470 GDD), instar 4 (550 GDD), cocooning (600 GDD), pupa (725 GDD), adult emergence (815 GDD). (Source: R.I. Carruthers)

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

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, ground hogs, deer, etc.).
*Mow around farm buildings to minimize rodent and other pest habitat

Alfalfa and Grass Hay:
*Monitor alfalfa for crop condition, watch re-growth for alfalfa weevil, potato leafhopper, and diseases.
*Evaluate alfalfa seedings for weeds, insects (potato leafhopper) & diseases.

Small Grains:
*Monitor winter grain fields for crop growth stage, signs and symptoms of diseases, weed pressure, insects (cereal leaf beetle, true armyworm)
*Monitor winter wheat for foliar & grain head diseases, potential for Fusarium Head Blight

Field Corn:
*Post emergence: Determine corn plant populations, monitor for emergence problems, weeds, noting presence of "who", "how many" and "where"
* Early season corn pests: seedling blights, seed corn maggot, white grub, wireworm, black cutworm, true armyworm, slugs, birds
*Adjust post emergence weed control actions

*Post emergence: Determine plant populations, monitor for germination and emergence problems, monitor for weeds, noting presence of "who", "how many" and "where"
* Monitor for soybean aphid, sliugs

*Check and mend fences as needed.
*Check crop growth
*Check for presence of undesirable plant species harmful to livestock.
*Monitor forage grasses for armyworm

*Arrange for custom weed / disease management 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 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 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