Weekly Field Crops Pest Report 2006

View From The Field

Eastern NYS
Ken Wise, NYS IPM

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Western NY and Finger Lakes
Julie Stavisky, NYS IPM

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This week at the SUNY Cobleskill Farm potato leafhopper populations remained low. But at the Cornell University Research Farm in Valatie all alfalfa fields were over threshold for Potato leafhopper. The alfalfa plants are showing the typical v-shaped yellowing at the tips of the leaflets. I was getting about a 100 potato leafhoppers in 3 samples in 18 inch alfalfa.

Also at the Cornell University Research Farm in Valatie I discovered something I had not seen before. European corn borer in inhabiting the stems of triticale. European corn bore damage renders the grain head white without any grain fill. About 15 to 20% of the grain heads in this plot area were infected with European corn borer. The following are a few photos of the pest and its damage to the small grain.

European Corn Borer Entry Hole

European Corn Borer in Triticale

European Corn Borer Pupa in Triticale

European Corn Borer Damage in Triticale

In the soybean sentinel plot in Columbia County I discover soybean aphids. There were very few aphids. Most plant had no aphids and just 3 of the 50 plants I observed had 1-3 aphids. Here is a photo of the aphids.

Soybean aphid

I observed an egg mass of spined soldier bugs in the process of hatching on a soybean leaf (see photo below).

This generalist predator is always a pleasant sight when soft-bodied pest insects are nearby.  I saw an adult, but it was camera-shy.  Here is a link with more information and a nice photo.

I observed soybean aphids in the Wayne County soybean rust sentinel plot this week.  There were aphids on about 20 % of plants, ranging from 2 to 64 aphids.

Start Thinking CORN ROOTWORM: What Fields are at risk?

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Corn rootworm populations build in a cornfield from year to year. Fields that are not rotated and remain in corn for several years are most at risk from corn rootworm damage. A two to three year rotation reduces the risk that a corn field will reach an action threshold for this pest. This spurs the question, “Do you scout a 1st year cornfield after sod for corn rootworm?” Yes, because any pollinating cornfield can attract corn rootworm. Even worse, late pollinating corn can attract many hungry corn rootworm beetles from fields where they did not get enough pollen. After the beetles eat their fill on late season pollen they will lay eggs in the soil. So yes, you have to scout all cornfields for corn rootworm that are going to be planted to corn next year. You do not need to scout fields that will be rotated out of corn next year. For more information on corn rootworm please see the Corn Rootworm Management Guide.

European Corn Borer Opens the Door for Anthracnose Stalk Rot

Ken Wise, NYS IPM

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While scouting, I observed signs of European corn borer (ECB) in field corn. There were broken leaf midribs, frass in the whorls, and holes in the stalks. European corn borer damage, can on occasion cause localized problems for field corn producers. However, while it's damage may be conspicuous, it more typically does not cause significant economic losses in NYS. If a field has had a history of ECB problems producers might consider crop rotation or the use of an ECB resistant (Bt) hybrid. In addition to direct feeding damage the holes bored by ECB larvae can provide a means for the anthracnose fungus to enter the plant. Conditions that favor anthracnose stalk rot are continuous corn, surface corn residue (minimum & no tillage) and wet, humid, warm weather. Anthracnose stalk rot symptoms may appear after tasselling. Look for vertical, tan to reddish brown, water-soaked lesions (streaks) in the rind. Lesions become large, dark brown to shiny black. The best management practices to minimize or avoid anthracnose require action before or at the time of planting, i.e. the use of diseases resistant hybrids and hybrids with a good standability rating. Crop rotation with non-grass crops and plow under infected residue are also recommended. Fields with high amounts of anthracnose leaf blight should be checked for indications of anthracnose stalk rot. If stalk rot is found you may wish to target that field for early harvest to avoid losses associated with premature lodging. For more information on corn diseases please see Diseases of Corn Management Guide.

Soybean Rust Update

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Nearly all of New York's soybean acreage has been planted and plants range from V1 (just emerged) to R1 (flowering).  Weekly scouting is occurring on 19 sentinel plots located in Cayuga, Chautauqua, Chemung, Chenango, Columbia, Genesee, Jefferson, Montgomery, Oneida, Onondaga, Ontario, Seneca, Tompkins, Wayne, and Wyoming Counties. Low levels of Septoria brown spot were found in several of the sentinel plots. The current risk of soybean rust infection in New York is extremely low. Future risk in New York will depend on rust build-up in the southern U.S., especially in commercial soybean fields. To date, in 2006, soybean rust has been reported in five counties in Alabama, 12 in Florida, one in Texas, four in Georgia, and one in Louisiana. Currently, there are no known reports of rust on commercially planted soybean in 2006. Many of the southern states have previously experienced hotter and drier than normal conditions, reducing the likelihood of viable spore dispersal.  Recent rains are expected to renew rust development and spread in the South, though rust spore production is currently considered to be very low. Last updated (July 3, 2006)

New York Soybean Rust Site

Growing Degree Days in NYS

Ken Wise NYS IPM

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Accumulated Growing Degree Days for March 1 to July 6

*indicates missing data

Source: NEWA

Clipboard Checklist

Keith Waldron-NYS IPM

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General:
* Update crop records by field, including pesticides used, nutrient inputs including manure, growth and development observations, other comments, etc.
- Record hay crop yields by field and quality by storage facility; take samples for forage analysis
- Inventory remaining corn silage and allocate forages for summer feeding
* Clean and prepare storage areas for small grain harvest
* Adjust pasture rotation, check fencing, water sources
* Make plans for fun Fourth of July activity

Corn:
* Monitor fields for crop growth and condition, seed corn maggot, wireworm, cutworm, seedling blights, birds, armyworm
* Evaluate weeds and adjust post emergence treatments
- note presence of triazine resistant annual broadleaf weeds
-Cultivate or treat if necessary
* Pre-Nitrogen Sidedress Soil Test and apply sidedress as needed

Small Grains:
* Monitor for crop growth and condition, insect (cereal leaf beetle, armyworm, European corn borer) and disease problems Fusrium (scab) and other head and leaf blights)

Alfalfa & Hay:
* Monitor alfalfa seedings for crop growth and condition, weeds, potato leafhopper & diseases.
* Check established alfalfa stands for potato leafhopper, weed and disease problems
- Take alfalfa stand counts while regrowth is short (if not done earlier in the season)

Soybeans:
* Check stand establishment, crop growth and condition, weed control
* Evaluate stand for uniformity, seed corn maggot, wireworm, seedling blights, birds, planter problems, drainage issues
* Monitor for soybean aphid, soybean rust, presence of natural enemies

Dairy Livestock Barn Fly Management
Barn Areas:
* 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 water sources, drainage, roof gutters for leaks and potential overspill
* Collect and evaluate "3X5" index card fly speck monitoring cards. Record results for future comparisons. Replace with new cards
* Evaluate animals for stable fly harassment (10 stable flies per animal)
* Replace fly sticky tapes as needed, check insecticide bait trap
Pasture:
* Check condition of pastures and animals on pastures
- Evaluate need for face fly and stable fly control measures
- Insecticidal ear tags for heifers (non-lactating animals) on pasture
- Adjust pasture rotation, check fencing, water sources

Equipment:
* Note any repairs needed for recently used equipment: tractors, harvest equipment and wagons, etc. as they are cleaned and serviced.
* Calibrate manure spreaders - maintain records on amount spread per field
* Prepare small grain combining equipment or arrange for custom combining

Contact Information

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Julie Stavisky: IPM Area Educator, Livestock and Field Crops, Western NY
Phone: (315) 331-8415
Fax: (315) 331-8411
Email: js38@cornell.edu

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