NYS IPM Weekly Field Crops Pest Report – August 28, 2012

This newsletter on-line at: www.nysipm.cornell.edu/lfc/tag/pestrpt/index.html

In this issue:

  1. View from the Field
  2. Weather Outlook
  3. Western Bean Cutworm Update
  4. Clipboard Checklist
  5. Contact Information

View from the Field

Soybean Vein Necrosis Virus Symptoms (Photo Gary Bergstrom)

While scouting soybean fields in Dutchess County, I (Ken Wise) found leaflets that look like soybean vein necrosis virus (SVNV). We still need to confirm that this is SVNV though Cornell’s Plant Pathology Diagnostic lab. For more information, refer to last week’s pest report: http://www.nysipm.cornell.edu/fieldcrops/tag/pestrpt/default.asp#SVNV

Reports of several other soybean diseases came in this past week: septoria brown spot, downy mildew, bacterial blight, bacterial pustule, and frogeye leaf spot. These diseases rarely cause economic losses to soybeans in NY.

Clover root mealy bug

A few reports of soybeans leaves with yellow discoloration suggested potassium deficiency. But closely inspecting the roots revealed an insect — a type of mealybug. Last summer, mealybugs were collected in Yates County on soybean roots and identified as clover root mealy bug (photos below). Potential importance and economic impacts of this insect are poorly understood. This summer, mealybugs have been collected from soybean roots in Delaware and Livingston counties. If you find mealybugs on soybeans showing signs of the potassium deficiency — please collect samples! We would be very interested in hearing from you and learning more about this mysterious pest.

Dodder, an orange spaghetti-like weed, (Cuscuta spp.) in Chemung, NY

Keith Waldron found dodder, an orange spaghetti-like weed, (Cuscuta spp.) in Chemung, NY. This parasitic weed is occasionally found in alfalfa and other broadleaf species. Dodder in the photo below was on “touch-me-not” growing along a roadside. Dodder gets most of its nutrients from the plants it grows on, being almost incapable of photosynthesis. As the mass of dodder vines expand, it coils around and attacks to new hosts. If you find dodder on your farm, destroy as quickly as possible to curb the chance it will infest other fields.

Spider mites have done considerable damage to field corn at the Cornell Research Farm in Valatie. And reports of spider mite damage on soybeans in areas of western NY are still coming in.

Lately I’ve seen some defoliation on soybeans. Most is due to Japanese beetles, Mexican bean beetles, and grasshoppers. While these are minor pests, defoliation sends up red flags for growers. How much leaf defoliation is too much in soybeans? The good news: soybeans can withstand much defoliation without losing yield. The threshold from V1 to just before bloom: 35 percent of leaf area eaten or missing. From bloom through pod-fill, the threshold is 20 percent.

While conducting a barn fly IPM meeting in Oneida County we discovered a large population of stable flies. Stable flies bite and take blood from the legs of cattle. The economic threshold is an average of 10 flies per 4 legs on at least 15 animals. While the average was around 20 per cow, we found as many as 50 on one animal. For more information see article below.

 

Weather Outlook – August 23, 2012
Jessica Rennells, NOAA Northeast Regional Climate Center, Cornell University

Last week temperatures ranged from 0 to 6 degrees below normal for most of the state; quite a difference from what we’ve seen this summer. Rainfall ranged from a trace to one inch. Base-50 growing degree-days ranged from 75 to 125, lower in the Adirondacks.

High pressure, warming temps, overall a dry week. Today will be mostly sunny with highs in the 80s. Tonight’s temperatures will be in the 50s.

Wednesday temperatures will be cooler, in the low to mid 70s with showers still possible depending on the timing of the front. Lows will be in the mid to upper 50s.

The five-day precipitation amounts will range from a tenth to a quarter of an inch. The 8-14 day (Aug 30 – Sept 5) outlook is showing above normal temperatures and above normal precipitation. The September outlook is showing above normal temperatures but uncertain precipitation. Tropical Storm Isaac should not have any impact at least through Wednesday.

National Hurricane Center/ Isaac:
http://www.nhc.noaa.gov/refresh/graphics_at4+shtml/115735.shtml?5-daynl#contents

Maps of 8-14 day outlooks:
http://www.cpc.ncep.noaa.gov/products/predictions/814day/index.php

National Weather Service watch/warnings map:
http://www.erh.noaa.gov/er/hq/

NRCC Drought Page which features the US Drought Monitor map (updated every Thursday):
http://www.nrcc.cornell.edu/page_drought.html

 

Western Bean Cutworm Update
Keith Waldron, NYS IPM              

Average number of western bean cutworm moths captured per trap.

Western bean cutworm captures declined again this week; a number of traps caught none. So far, 73 WBC moths were caught in the 50 traps reporting this week — less than half the number caught last week. Catches ranged from 0 to 16. The majority of our accumulated NY trap catch numbers are relatively low, indicating no cause for economic concern. Interestingly, 13 traps have caught less than a total 10 WBC moths so far this season. The high WBC count this week was 16 in Eden (Erie County).

Meanwhile, WBC larvae were collected in Lowville (Lewis County) this week. In the weeks ahead be on the lookout for signs of larval feeding in corn ears. WBC infested ear could contain more than one larva. Larvae could enter through the silk channel at the ear tip or bore through the husk or ear shank.

Accumulated western bean cutworm moths per location as of 8.24.12

Excessive bird activity and damage could indicate insect larvae are in the ears. Damage can open ears to risk of ear molds.

More WBC monitoring information is available at:

Western Bean Cutworm identification card – including larval stages.

Cornell Sweet Corn Monitoring Network

Penn State Pest Watch (Includes WBC data from NY, New England and other state)

Ontario WBC Trap Network

Cornell Field Crop Extension Homepage: “field crops.org” “blog” section.

Western Bean Cutworm – Corn scouting videos:

Ontario

Wisconsin

The NY WBC trapping program will continue through the end of August.

 

Clipboard Checklist
Keith Waldron, NYS IPM              

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 any patches of herbicide resistant weeds, weed escapes

Corn:

  • Monitor fields for plant vigor, growth stage, late season pest issues (European corn borer, foliar diseases, nutritional deficiencies, vertebrate damage)
  • Monitor for weeds, note presence of “who”, “how many” and “where”
  • Monitor reproductive stage corn fields for foliar diseases, stalk standability issues, corn ear damage (insect pests and diseases)
  • Prepare storage areas to accept upcoming silage harvest

Alfalfa & Hay:

  • Monitor alfalfa seedings for weeds, insects & diseases.
  • Check regrowth of established alfalfa stands for potato leafhopper, weed and disease 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, natural enemies, defoliating insects, spider mites, bean leaf beetles and weed escapes

Dairy Livestock Barn Fly Management:

  • Sanitation, sanitation, sanitation – clean animal resting areas, feed throughs, 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
  • Continue fly monitoring: install “3X5” index card fly speck monitoring cards throughout barn
  • Install/refresh/replenish as needed: fly tapes, insecticide baits, natural enemies (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), face flies (10 per animal face), stable flies (10 per 4 legs). See IPM’s Livestock page.
  • Consider installing biting fly traps to reduce horse, deer and stable fly populations.

Storage:

  • Check temperature, moisture, pest status of recent bin stored 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, tillage implements, 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 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.

 

Contact Information
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

 

 

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