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Weekly Field Crops Pest Report 2009

Auguest 21, 2009                     Volume 8 Number 17

1. View from the Field

2. Certified seed and fungicide seed treatment are good insurance for winter wheat

3. Check For Stalk Rots!

4. Soybean Rust Update

5. Soybean Aphid Update

6. Clipboard Checklist

7. Contact Information

View from the Field

Ken Wise
NYS IPM

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Soybean aphid populations have dropped dramatically in many areas of the state this week. Spider mites were observed in high numbers in a drought stressed soybean field in western NY. White mold has been observed in reproductive stage soybean fields with closing foliar canopy.

Various foliar diseases, including gray leaf spot and northern corn leaf blight, are evident in field corn across the state.

Flies affecting animals on pasture or around barns have increased. Face flies and horn flies on pastured animals can become a major problem as the summer continues. We have also heard that pink eye has started to show up in a few herds of pastured cattle. Pink eye is vectored by face flies. Horn flies and other biting flies like stable, horse, and deerflies can also cause a lot of irritation to cattle. During a pasture walk meeting this week Keith Waldron discussed a few biting fly traps that can be used to help reduce the breeding population of biting flies in a pasture setting. A variety of traps are available commercially. The first trap discussed is for tabanid flies (Horse and Deer flies) and Stable Flies was a modified Manitoba trap commercially available as the Horse Pal Fly Trap

Horse Pal Fly Trap

Flies Caught in the Horse Pal Trap in 1.5 hours.

A second biting fly trap demonstrated is made with alsynite a flexible fiberglass-like material is very effective for catching stable flies. Alsynite fiberglass is specially made to reflect a certain spectrum of light attractive to stable flies. Clear fly paper is attached to the outside of the alsynite column and the stable flies get stuck on the trap. The trap demonstrated was the Olson Biting Fly trap.

Alsynite Biting Fly Trap

Certified seed and fungicide seed treatment are good insurance for winter wheat

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Soilborne fungal disease occurrence on roots, stems, and crowns of winter wheat are generally not severe when wheat growers rotate with non-cereal crops. However, low levels of soilborne and seedborne fungal diseases can cause problems with stand establishment. A stand that is not well established in the fall will have a harder time making it through the winter, and may not be as quick to green up in the spring.

Seedling disease threats can largely be prevented with the use of fungicide-treated seed. These threats include the smut diseases that maybe present on the surface of the seed or deep inside the embryo of the seed. Also, several soil-dwelling disease agents can cause plant roots and/or crowns to rot before the plant becomes established. In addition, seed fungicide treatments can aid in the suppression of early foliar diseases such as powdery mildew in the fall.

Fungicide-treated seed is widely available commercially, or treatments of fungicides can be made on-farm. The most effective treatments combine a systemic fungicide and a protectant fungicide. For specific reference to chemicals, please visit the Cornell Guide for Integrated Field Crop Management.

Another key tactic for good stand establishment is to plant certified seed. Use of certified seed assures a grower that seed meets high state and national standards for purity, identity, and freedom from noxious weed seeds and seedborne diseases.

Check For Stalk Rots!

Ken Wise
NYS IPM

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It is important to monitor your fields for stalk rots as you start thinking of your corn harvest. If you have an infection of stalk rot it can cause the plant to die early losing grain or silage yields. Stalk rots are caused by many different fungi that enter the plant. They occur when the plant is under stress or when it may be injured by insect pests, hail, deer and bird damages, drought or soil saturation, lack of sunlight, extended cool weather, and the lack of fertility. The following are symptoms of specific stalk rots:

Anthracnose stalk rot symptoms may appear after tasselling as vertical, tan to reddish brown, water-soaked lesions (streaks) in the stalk rind. Lesions become large, dark brown to shiny black. Fields with high amounts of anthracnose leaf blight (both diseases have the same causal agent) should be checked for indications of anthracnose stalk rot.

Diplodia stalk rot symptoms may appear as numerous black pycnidia in the lower internodes of the stalk. The black dots are the size of a pinhead or smaller. When conditions are wet a white mold may develop on the stalk surface.

Fusarium stalk rot normally starts just after pollination and symptoms appear later in the season. When you cut open the stalk, the pith appears as a whitish to pink (salmon) color. There are also distinctive brown streaks on the lower internodes.

The first symptom of gibberella stalk rot is the onset of grayish-green color of the leaves. The stalk will turn dark green to tan near the base of the plant. The pith of the stalk becomes soft and will appear as a red to pinkish color.

Pythium stalk rot normally appears as a decay of the first internode above the soil. The pith will become soft, turn brown and appear water-soaked. Many times the stalk can twist and/ or lodge. Even though it may have lodged the plant will stay green for several weeks because the vascular tissue is not destroyed.

If you discover certain stalk rot diseases make notes of the hybrid, tillage methods, rotation history, and planting date. By doing this you be able to avoid the disease occurrence in the future. The following is the effectiveness of specific management practices for stalk rots:

Corn Disease
(Stalk Rots)
Resistant Variety
Crop Rotation
Clean Plow
Down of Residue
Fungicides
Anthracnose
1
1
1
4
All Other
2
3
3
4
1= highly effective, 2= moderately effective, 3=slightly effective, 4= not effective, 5 = not usually economical,
Reference: Purdue University Field Crops Pest Management Manual

As with most diseases that attack corn, if you can reduce stress on the plants you most likely can reduce the occurrence of certain stalk rots. Having a sound fertility program based on soil testing is important for keeping a corn plant healthy. Select a hybrid with resistance to certain diseases and good standability that is adapted to your region. Some of these stalk rots can produce mycotoxins that can be toxic to livestock. You should consider having silage tested for certain mycotoxins if you had fields with stalk rots this season. For more information on corn diseases see our Diseases of Corn Management Guide.

Soybean Rust Update

Gary Bergstrom
Cornell University

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Scouting has begun in sentinel plots in NYS in Cayuga, Jefferson, Seneca, Washington and Wayne counties. This week low levels of bacterial blight and Septoria brown spot were detected in samples submitted from the NYS sentinel network. Nationally, on August 4th, soybean rust was reported on soybean in a sentinel plot in Baldwin County, Alabama. Additionally, recent detections of soybean rust have been made on kudzu in Alabama and Florida. Risk of spore transport to our region is low at this time. In 2009, soybean rust has been reported in the U.S. in 34 counties in five states (Alabama, Florida, Georgia, Louisiana and Texas). Updated August 7, 2009

Soybean Aphid Update

Keith Waldron
NYS IPM

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Crop Growth Stage Last Modified: 08/06/09 03:46 PM

Soybean growth variable across state. Majority of fields currently reporting early pod fill R3.

Observation and Outlook - Insect Last Modified:08/20/09

Soybean aphid populations appear to be moderating
this week with many fields below threshold.  Although field by field variations still exist, in some cases SBA's have actually been difficult to find in some areas where they were once very common. Populations of beneficial arthropods including Coccinelids, syrphid flies, lacewings, parasitic wasps and fungal pathogens have been increasing statewide. Spider mites have been observed in fields challenged by drought stress.

Scouting and Management - Insect Last Modified:08/20/09

SBA infestations variable on farms. Monitoring individual fields recommended to provide the best information for management decisions. Producers are encouraged to monitor soybean fields for this insect pest, natural enemies, spider mites and mid to late season soybean diseases. Follow management guidelines as recommended in USDA protocols and Cornell Recommendations for Soybean Integrated Field Crop Management.

Clipboard Checklist

Keith Waldron
NYS IPM

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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, pesticidesused, nutrient inputs including manure, etc.
* Watch for any patches of herbicide resistant weeds, weed escapes
* Storage areas cleaned and ready to accept hay, wheat harvest

Corn:
* Monitor fields for plant vigor, growth stage, mid to late season pestissues (European corn borer, armyworm, foliar diseases, nutritionaldeficiencies)
* Monitor for weeds, note presence of "who", "how many" and"where"
* Monitor reproductive stage corn fields for corn rootworm beetles and otherinsect pests and diseases.

Alfalfa & Hay:
* Monitor alfalfa seedings for weeds, insects & diseases.
* Check regrowth of established alfalfa stands for potato leafhopper, weed anddisease problems.
* Storage areas cleaned and ready to accept incoming harvest

Soybeans:
* Evaluate stand growth, development and condition
* Monitor fields for soybean aphid, foliar diseases, white mold, naturalenemies, defoliating insects, spider mites, bean leaf beetles and weed escapes

Dairy Livestock Barn Fly Management:
* Sanitation, sanitation, sanitation - clean animal resting areas, feedtroughs, minimize source of moist organic matter i.e. fly breeding areas inbarn and in adjacent animal loafing yard
* Check water sources, drainage, roof gutters for leaks and potential overspill
* Continue fly monitoring: install "3X5" index card fly speckmonitoring cards through out barn
* Install/refresh/replenish as needed: fly tapes, insecticide baits, naturalenemies (parasitoids)

Dairy Livestock Pasture Fly Management:
* Monitor animals for presence of pasture fly pests. Treatment guidelines:Horn flies (50 per dairy animal side, 100 per side for beef cattle), faceflies(10 per animal face), stable flies (10 per 4 legs). See IPM'sLivestock page.

* Consider installing biting fly traps to reduce horse, deerand stable fly populations.

Storage:

* Check temperature, moisture, pest status of recent binstored small grains
* Keep areas around storage bins and silos clean and mowed
* Check areas around storage bins and silos for vertebrate tunneling
* Check temperature of recently baled hay in hay mow

Equipment:
* Note any repairs needed for recently used equipment: tractors, tillageimplements, planters, sprayers, etc. as they are cleaned and serviced.
* Service hay harvesting equipment as needed.
* Calibrate manure spreaders - maintain records on amount spread per field

PESTICIDE EMERGENCY NUMBERS
Emergency responder information on pesticide spills and accidentsCHEMTREC:  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 Departmentof Environmental Conservation Spill Response:_800-457-7362(inNYS)_518-457-7362(outside NYS)
Poison Control Centers: Poison Control Centers nationwide: 800-222-1222. If youare unable to reach a Poison Control Center or obtain the information yourdoctor needs, the office of the NYS Pesticide Coordinator atCornellUniversity,607-255-1866, may be able to assist you in obtaining suchinformation.

Contact Information

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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: Field Crops and Livestock
Phone: (518) 434-1690
Fax: (518) 426-3316
Email: klw24@cornell.edu