Weekly Field Crops Pest Report 2008

View from the Field

Ken Wise
NYS IPM

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Corn silage harvest is now underway in much of NY. Northern NY CCE educators Mike Hunter (Jefferson County) and Joe Lawrence (Lewis County) report high winds from Hurricane Ike lodged corn Sunday evening affecting harvest. BMR corn and tall silage corn with less stalk strength were particularly affected. To enable a more efficient harvest many growers had to purchase a kit to add to the chopper head to pick up lodged corn. The flattened corn fields should be the highest priority to harvest for silage because the close proximity to the ground can provide an ideal environment for diseases, especially corn ear molds. 

Mike Stanyard (NWNY Dairy, Livestock, & Field Crops Team) reports ears of field corn damaged by birds and showing signs of pink mold. Steven Canner (St. Lawrence County) also reports corn ear diseases and common smut in several fields.

Soybeans are nearing harvest in many areas with early maturing varieties having lost most or all leaves. Mike Stanyard reports observing more soybean fields with white mold. He states 2.3 to 2.9 maturity group soybean cultivars seem to be more infected with white mold that other maturity groups.

Ken Wise (Eastern NYS IPM) reports soybean aphids averaging 14 SBA's per plant with up to 60 SBA's per plant were observed on R6 stage soybeans in Columbia county. There were a few winged aphids, indicating the population may begin to leave soybean fields to lay eggs on buckthorn their overwintering host. Very low SBA numbers (< 10 / plant) have also been reported in Cayuga and Niagara counties.

Weather outlook - 9.18.08

Art DeGaetano
NOAA NE Climate Center, Cornell University

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Last week saw warmer than normal temperatures across the state.  Almost all regions were near 3 degrees above normal.  Most of upstate NY accumulated between 75 and 100 GDD, with up to 125 in the Lower Hudson Valley and 150 on Long Island.  Seasonal totals are now nearly 2000 in the North Country, about 2300 across central NY, including the Buffalo and Albany Areas.  There are nearly 3000 seasonal degree days near New York City.  These totals are about 150 behind last year's in the west, but 150 ahead of last year in the east. The state as a whole is generally within 100 GDD of the long term normal.

The week saw as much as 2 inches or rain in the extreme western NY. Most of the rest of the state saw between 0.5 - 1.0 inches of rainfall.  The driest areas were in and around NYC where less than 0.5 inches fell.

A large high pressure system will dominate the weather through the weekend. With high pressure over the state tonight, frost will be likely in many places in central NY, especially away from the Lakes.  Through Sunday highs will be in the 70s which is a few degrees above normal, and lows will be near normal in the 40s. A cold front will pass the state on Sunday, however it will have little moisture to work with.  Expect rain free conditions through next Wednesday.  Temperatures will cool to below normal levels behind the front on Monday and Tuesday (mid 60s- low 70s during the day and 40s at night), but rebound to above normal values by mid week. In the 8-14 day period, a ridge will dominate the Northeast's weather bringing dry and warmer than normal conditions.

Fall Weed Survey - Invasive species and Plants affecting Livestock

Keith Waldron
NYS IPM

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Harvest season is upon us and with it another opportunity to visit fields up close and personal. This is a great time to take stock of what field issues can be found and note them in field records to enhance future management decisions. Note particularly good and bad areas, differences in crop height, plant populations, drainage, yield, etc. Updates on pest presence or damage can also be noted at this time.

An easily visible pest group to document this time of year are weeds. What species? Where are they found? How many are there? What management type (annual, perennial, biennial, grass or broadleaf species? Knowing this information helps to refine weed management decisions and develop next years cropping plans. See: " Think Weeds in the Fall! ", a topic in the August 21, 2008 issue of the Weekly Pest Report. The focus of that article was how to conduct a fall weed survey to get the information you can use in next years weed management program.

While visiting fields to conduct the fall weed survey note presence of troublesome perennial species like Canada thistle and milkweed and potentially invasive species such as spiderwort, garlic mustard, Japanese knotweed, leafy spurge, multiflora rose and spotted knapweed growing in or around production and fallow fields, pastures, in fence lines or in windbreaks. Many websites have information on invasive plant species. One example to check out that has information on invasive herbaceous and woody plant species is: 18 Common Invasive Plants in New York State.

If you raise livestock, fall is also a good time to assess pastures and other grazed areas for presence of common weed species known to be harmful to animals. These species include horsetail (Equisetum spp), poke weed, St. Johnswort, tall buttercup, jimson weed, common milkweed and among others. A listing of some common plants poisonous to livestock can be found in the publication: Common Weeds Poisonous to Grazing Livestock.

Learn more about Plants Poisonous to Livestock and other Animals.

Soybean Rust Update

Gary Bergstrom
Plant Pathology, Cornell University

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Soybean rust has not been detected in New York The current risk of soybean rust in New York is considered to be low. No management practices are warranted for the remainder of 2008.

Sentinel soybean plots in New York State continue to be scouted weekly in the following counties: Chautauqua, Chemung, Columbia, Cortland, Jefferson, Lewis, Niagara, Oneida, Ontario, Steuben, Wayne and Yates. Plant growth stages in sentinel plots range from R5 to R6. Moderate to high levels of Septoria brown spot and downy mildew are occurring in several of the sentinel plots. Frogeye leaf spot is present at low levels in several locations, and bacterial pustule was detected in Jefferson County. Sentinel plot scouting has been completed for the season in Cayuga, Madison, Schoharie, and Seneca Counties.

Since January of 2008, soybean rust has been reported in eight counties in Alabama; five counties in Arkansas; 10 counties in Georgia, 22 counties in Florida; four counties in Louisiana; 13 counties in Mississippi, and five counties in Texas. Movement of rust spores with the recent hurricane disturbances has moved spores northward.  Even if viable spores land in New York soybean fields this fall, the crop is nearing maturity and rust will not impact yield. (Updated September 15, 2008)

NY State Soybean Rust Hotline: 607-255-7850

NYS Soybean Rust Website

USDA Soybean Rust Website

Soybean Aphid Update

Keith Waldron
NYS IPM

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Soybean aphids (SBA) have been difficult to find across NY this week. Monitored fields are typically averaging 0 to less than 10 SBA's per plant at this time. An eastern NY sentinel field had the highest reported population with an average of 14 SBA's per plant with up to 60 SBA's per plant observed in R6 stage soybeans. Winged aphids were observed in this field indicating potential for SBA movement from field. All fields reporting well below threshold.

Low SBA populations, maturing soybeans, and more frequently predicted frost warnings indicate the end of SBA season is in sight. Natural enemy populations, such as ladybird beetles, are present in most areas.  Japanese beetles are still active in fields, however, defoliation damage has generally been minimal.

Crop Growth Stage - Soybeans are generally in later reproductive stages. Early season maturity soybeans (0.9) nearing total leaf loss, while later maturity groups (3's) still green. Soybean heights vary from 16 inches to 30 plus inches tall.

Soybean aphid scouting and management - Low soybean aphid numbers typically observed in nearly mature growth stage soybeans indicate negligible risk to soybean yields from this pest. Midwest research has shown no economic return on insecticidal applications during the R7 and R8 growth stages.

It is possible that weather fronts may carry SBA's eastward from infested areas of the Midwest. Growers are encouraged to monitor soybean fields for presence of soybean aphids, other insects, and diseases such as white mold.

Soybean aphid management decisions should be based on a field visit and SBA population assessment. Research has shown no economic return on insecticidal applications During the R7 and R8 growth stages

For more information see: USDA Public PIPE Website: Management Toolbox-Guidelines-USA

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, pesticides used, nutrient inputs including manure, yields, etc.
* Watch for weed escapes, any patches of herbicide resistant weeds?
* Prepare bunkers, silos for incoming silage.
* Mow around storage bins, barn and farm facilities
* Note presence of potentially invasive weed species such as black and pale swallow-wort, garlic mustard, Japanese honeysuckle, japanese knotweed, multiflora rose, purple loosestrife, and spotted knapweed.

Alfalfa & Hay:
* Monitor alfalfa seedings for weeds, for potato leafhopper & diseases.
* Check established alfalfa stands for potato leafhopper, weed encroachment and disease problems.
* Storage areas cleaned and ready to accept next harvest?
Small Grains:
* Check grain storage bins for temp, moisture, air flow, drying conditions.
* Plant winter wheat after Hessian Fly-free date

Field Corn:
* Note crop growth stage and condition
* Check for European corn borer, armyworm, foliar and stalk rot diseases, vertebrate injury (birds / deer), weed escapes, herbicide injury, nutritional deficiencies, etc.
* Check corn for grain fill issues - mold, insects, vertebrate damage
* Monitor weed populations noting presence of "who", "how many" and "where"
* Harvest corn silage at 65 to 68% moisture and high moisture shelled at 25 to 30% grain, and high moisture ground-ear at 30 to 35% moisture.
* Record corn silage yields by field and quality by storage area, take samples for forage analysis
* Take Soil Samples for fertility analysis
* Take Fall Weed Survey following harvest.

Soybeans:
* Note crop growth stage and condition
* Evaluate stand for soybean aphid, white mold, foliar diseases, sudden death syndrome (Fusarium solani f. sp. glyines), and brown stem rot (Phialophora gregata f.sp. sojae)
* Harvest when soybeans reach safe storage moisture level of approximately 13%.
* Review combine settings and speeds to minimize seed damage

Dairy Cattle: Livestock Barn Fly Management:
* Monitor animals and facilities for house fly and stable fly populations
* 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 through out barn
* Use, replenish, replace fly management materials: sticky fly tapes/ribbons, insecticide baits, natural enemies (parasitoids), fly population monitoring (3 x 5) spot cards

Dairy Cattle: Pasture Fly Management:
* 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

Storage:
* Pre-clean in and around grain storage bins in anticipation of soybean and grain corn harvests.
* Keep areas around storage bins and silos clean and mowed

Equipment:
* Provide annual maintenance to manure, fertilizer, and pesticide application equipment
* Prepare combines for corn, soybeans
* Sharpen chopper knives. Check shear clearances, protective shields
* Note any repairs to harvesting equipment as they are cleaned and lubricated.

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