Weekly Field Crops Pest Report 2009

View from the Field

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Alfalfa weevil (AW) infestations across the state have reached threshold in several fields. Most alfalfa that is over threshold for AW were fields that have not been harvested. Jeff Miller, Mike Stanyard, Brain Aldrich, and Ken Wise all report alfalfa fields over threshold for AW. Some of the fields ranged from 60 to 100 percent tip feeding. The economic threshold for AW before first cutting is 40% of the stem tips show feeding damage.

Mike Stanyard reports that growers are dealing with weeds in field corn. He states that lambsquarters are 4 to 5 inches tall. Growers in the NW region of the state are busy spraying corn fields for weeds. Mike also suggests that slugs have been feeding on soybean seedlings in a few fields.

Fireflies observed in Capital District (Kinderhook) and Finger Lakes ( Geneva area) of central NY. Timing of the first firefly sightings usually coincide with hatch of corn rootworm eggs.

Weather Outlook 6.02.08

Drew Montreuil
NOAA Northeast Regional Climate Center, Cornell

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Temperatures returned to below normal levels this past week, but only a couple degrees cooler than normal in the west. Areas east of I-81 were cooler, running 3 to 6 degrees colder than average, with a few places even up to 9 degrees below average. Precipitation was widespread, with most areas picking up between 1 and 2 inches. Areas Downstate were the exception, where less than 1 inch fell. Some places in the Southern Tier and Eastern regions picked up over 2 inches.

The Base 50 Growing Degree Days accumulated most in the west, where there were 50 to 75. Places east of I-81 got less than 50, while places in the Adirondaks received fewer than 25 growing degree days. For the year, this puts places near the Great Lakes and near Albany generally in the 300 to 400 range, while most other places are between 200 and 300. The North Country has slightly less, averaging between 100 and 200. Compared to last year, areas south of I-90 are 3 to 7 days ahead, while places north of the Thruway are within a couple days above or below last year. A similar gradient appears when comparing seasonal values to normal, with places south of I-90 as much as a week ahead and places north of I-90 as much as a week behind. That corresponds to about 75 growing degree days  above or below normal.

The weather pattern of the past few days has been very static, with a front stalled out to the south of New York. This has kept temperatures below average, but has been too far south for much in the way of rain. Areas across the Southern Tier could see some rain today, but anywhere north of I-90 will likely stay dry. The stalled front will finally start to move today, allowing for an extended period of sunshine starting tomorrow. Highs will gradually warm up as well, with low to mid 70s on Friday. Sunny conditions should continue right into Saturday, with highs in the low 70s to the north and west, and upper 70s in the south and east. Lows Friday and Saturday should be in the mid 40s to low 50s. A cold front will move through Saturday, but no precipitation is expected with it. Highs Sunday will be slightly cooler, with temperatures near 70 in the north and west, and mid 70s across the south and east. An area of low pressure will move towards the state from the southwest starting Monday, with highs in the low 70s statewide. As the low moves by Tuesday, highs will generally be in the upper 60s to low 70s. Lows Monday and Tuesday should be in the low to mid 50s. How much rain will fall with this low is still uncertain, as a slight change in the projected track can totally change the forecast. For the next 5 days, however, less than 0.25” of rain can be expected, with many areas seeing less than 0.05”. For the 8-14 day outlook, temperatures are expected to remain below normal, with precipitation near normal.

Soybean Seed Rot and Seedling Blight

Ken Wise
NYS IPM

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Many different organisms cause seed rot and seedling blights. Most of these organisms are soil-borne and a few are seed-borne. Most seed rots and seedling blights proliferate in poorly drained, cold (less than 58 degrees) and wet soils.

Seed Rot: Many times the infected seed will not germinate. If the seed does germinate the radicle will become infected and rot. The rot can be tan, brown, gray or black and the seed or radicle will appear wet and mushy. Some of the organisms that infect seed are Pythium, Fusarium, and Rhizoctonia.

Seedling blight: It is difficult to determine which pathogen causes seedling blight in any one field. Many times it can be a complex of Pythium, Rhizoctonia and Phytophthora. Pythium can cause the seedlings to have a wet, rotted appearance, while Phytophthora generally appears as a dry, dark rot on the roots. Sunken, reddish-brown lesions on the hypocotyls are most likely a Rhizoctonia infection. The Rhizoctonia lesions are small when they first appear. As these lesions grow they can girdle the stem, causing the soybean plant to die. If the Rhizoctonia infected seedlings do not kick the bucket the infection will weaken the stem and may cause the plant to lodge after the pods form.

Make sure you use a fungicide seed treatment to protect seed from these pathogens at planting. Do not plant soybeans too early when soil temperatures are low. If soil temperatures are low the seed will take longer to germinate and grow, thus allowing the pathogens more time to enter the seed.

Potato Leafhopper Identification and Potential Damage

Ken Wise
NYS IPM

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Potato leafhopper may soon show up in your alfalfa. Correct identification is essential managing potato leafhopper in alfalfa.

Potato leafhopper is a lime-green insect about 1/8 inch long and rides the storms that come from the south, looking for alfalfa and other host plants. The adult females are strong flyers and move from plant to plant laying 2-3 eggs per day. Bright yellow-green nymphs (looking much like adults, but smaller and wingless) hatch from the eggs to feed on plant juices. Nymphs and adults alike use their needle-like mouthparts to suck juices, replacing them with toxic saliva. Once you see V-shaped yellowing on the tips of the leaves it's too late. Potato leafhopper has likely reduced plant protein by 5% and yield by about .10 - .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. For more information on potato leafhopper checkout our online publication, Potato Leafhopper on Alfalfa Management Guide.

Potato Leafhopper Adult

Fusarium Head Blight Prediction Center Update

Gary Bergstrom
Department of Plant Pathology, Cornell University

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The majority of New York's winter wheat crop has reached or will reach anthesis during the interval of May 31 to June 8.  Predicted risk of Fusarium head blight (FHB) has been low to moderate for New York State during this interval, thus no general advisory for a fungicidal spray to suppress FHB this year.  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.  It is important to note when your wheat reaches anthesis and to check the Prediction Center each day.

Fungicidal Suppression Of Fusarium Head Blight:
Please note that the only fungicide available in New York for suppression of Fusarium head blight is propiconazole (4 fl. oz. per acre of Tilt or PropiMax applied at 50% of anthers emerged on primary tillers).  Fungicides such as Caramba, Folicur, Proline, and Prosaro are not yet registered for use on wheat in New York. (June 3, 2009)

Fusarium Head Blight Risk Assessment Tool

NYS Soybean Rust Information Center Update

Gary Bergstrom
Department of Plant Pathology, Cornell University

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2009 soybean rust detections to date have been on kudzu in Georgia, Florida, and Texas as well as along the gulf coast including Alabama and Louisiana. Soybean rust disease incidence and severity on kudzu in these states has been reported as low to medium. Precipitation in the affected areas may lead to further spore deposition in Georgia, the Florida panhandle and eastern Texas. 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. Soybean rust has not yet been detected on soybean in the U.S. in 2009. Please visit us again for future updates on soybean rust in the U.S. Updated May 26, 2009

NYS Soybean Rust Website

USDA Soybean Rust Website

Growing Degree Days in NYS

Ken Wise
NYS IPM

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CURRENT Accumulated Growing degree days (48F Base):

March 1 -   June 2, 2009

*Indicates missing data

Data from NEWA

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

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

Source: R.I. Carruthers

Clipboard Checklist

Keith Waldron
NYS IPM

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Clipboard checklist
General:
* 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?

Corn:
* 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?

Soybeans:
* Evaluate stand emergence - seedling blights, seed corn maggot, weed assessment, soybean aphid

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)

Storage:
* Check storage areas (bunk silos, etc.) for readiness to accept first cutting
* Keep areas around storage bins and silos clean and mowed

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

PESTICIDE EMERGENCY NUMBERS
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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June 4, 2009 -- Small Grains Management Field Day, Musgrave Farm, 1256 Poplar Ridge Rd, Aurora, NY

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
Email: klw24@cornell.edu

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