NYS IPM  Weekly Field Crops Pest Report,, August 18, 2017

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 Volume 16 Number 16

View from the Field

Downy Mildew (Peronospora manshurica) on Soybeans

There continues to be reports of downy mildew on soybeans. For more information see last week’s article on this issue: http://blogs.cornell.edu/ipmwpr/#Downy_Mildew_on_Soybeans

Fall Armyworm (Spodoptera frugiperda) in Field Corn

I found a field of late planted corn with fall armyworm damage. While fall armyworm does not normally cause issues in field corn it can with late planted corn. Mike Stanyard (CCE Northwest NY Dairy and Field Crops Team) has had issues in past years with fall armyworm in some of the late planted corn.

Fall Armyworm Damage

Fall Armyworm larvae are green, brown, or black about 1/8 inch to 1.5 inches long and have a dark head capsule usually marked with a pale, but distinct, inverted “Y.” Along each side of its body is a longitudinal, black stripe, and along the middle of its back is a wider, yellowish-gray stripe with four black dots on each segment.

Fall Armyworm Larvae

Larvae are active at night, but can be seen feeding on overcast days. Larvae can be found down in the whorl. If there are sufficient numbers and damage is present, an insecticide could be justified. Treat only the affected area and a 20 to 40-foot border around the infestation. Rarely does a whole field need to be treated for armyworm.

White Mold (Sclerotinia sclerotiorum) in Soybeans

There are several more reports of white mold infections in soybeans. This might be a year that we see a lot of white mold in soybeans with the excess rain and moisture we have received. For more information see the link to the article on white mold.  White Mold Sclerotinia Stem Rot in Soybeans

 

Northern Corn Leaf Blight (Exserohilum turcicum) and Gray leaf spot (Cercospora zeae-maydis)

Some extension educators are starting to find both northern corn leaf blight and gray leaf spot. In some late planted corn these diseases may cause some issues if the hybrid is susceptible. For more information see the following article published a few week’s ago: 2017 Corn Diseases and Plant Health in a Wet Growing Season

 

Corn Leaf Aphids (Rhopalosiphum maidis)

I found a lot of corn leaf aphids in brown midrib sorghum at the Cornell Farm in Valatie this week.  Even though there were a lot of aphids they really do not damage the sorghum. One reason is that there are some many predators of them. I found many lady beetles, syrphid flies, lacewings, blister beetles and more.

Corn Leaf Aphids

Aphid appear to be blue-green or blue-grey in color. They are about 2 mm in size. They have two very small tube-like projections called cornicles rising out of the top rear area of the abdomen. Many people call them “tail pipes”. The cornicles are short and darker than the rest of the body. There is a form of the aphid that has delicate transparent wings.  The nymphs appear the same as the adult just smaller.

It is not known if corn leaf aphids can overwinter in NY. They are not very cold tolerant. The  winged form of the aphid can ride weather fronts from the south to the northern states. They have a lot of hosts including corn, sorghum, grasses and small grains. Male aphids are rare to find and female aphid give live birth to nymphs. Each generation takes about 10 days.

Weather Outlook – August 17, 2017

Jessica Spaccio

NOAA Northeast Regional Climate Center, Cornell University

Last week temperatures ranged within 2 degrees of normal. Precipitation ranged from less than a quarter inch to 2 inches for most of the state. Base 50 growing degree-days ranged from 80 to 160.

Frontal systems will bring showers and thunderstorms Thursday into Friday. Sunday & Monday will be sunny and dry. The next system moves through Tuesday evening into Wednesday.

Today temperatures will be in the upper 70’s to mid 80’s. A frontal system will bring increasing clouds and a chance for showers and thunderstorms in the afternoon into the night, with heavy rain possible overnight. Overnight lows will be in the upper 50’s to upper 60’s.

Friday temperatures will be in the mid 70’s to low 80’s, with scattered showers and thunderstorms. There is a possibility of sever storms with hail, strong winds, and locally heavy rainfall. Overnight temperatures will be in the 60’s.

Saturday’s highs will be in the mid 70’s to mid 80’s with scattered showers possible. Overnight temperatures will be in the upper 50’s to mid 60’s.

Sunday will by sunny and dry with highs in the upper 70’s to mid 80’s. Overnight temperatures will be in the upper 50’s to low 60’s.

Monday’s highs will be in the 80’s with sunny conditions. Lows will be in the low to mid 60’s.

Tuesday will have temperatures throughout 80’s.  Lows will be in the low to mid 60’s. Showers and thunderstorms will develop overnight and continue into Wednesday with a passing cold front.

Wednesday, temperatures will be in the upper 70’s to mid 80’s with showers and thunderstorms.  Lows will be in low to mid 60’s.

The seven-day precipitation amounts will range from ½ ” to near 2”.

The 8-14 day outlook (Aug 24-30) slightly favors below-normal temperatures for western to north-central and southeast NY. The precipitation outlook slightly favors below-normal precipitation amounts for western NY to northeast NY.

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.weather.gov/erh/

US Drought Monitor

http://droughtmonitor.unl.edu/Home.aspx

CLIMOD2 (NRCC data interface):

http://climodtest.nrcc.cornell.edu

Planting Winter Small Grains? What are the Pest Issues?

Ken Wise, NYS IPM

Growing cereal grains is on the increase across New York. Many of the winter grains are about to be planted. Many producers are planting small grain cover crops this fall. Some will be planting winter wheat, winter rye, winter triticale and winter malting barley for grain and straw. Sometimes we forget that there are several diseases and insect pest issues with planting winter small grains. Here is a list of items to consider when planting.

  1. Do not plant cereal grains in the same field that had previously been a small grain. Rotation helps control many diseases like: scald, powdery mildew, Stagonospora nodorum blotch, glume blotch and more.
  2. Select a cultivar that is adapted for your region. Remember to select one that has resistant to many of the diseases in the area. The diseases you want to think wheat spindle streak mosaic virus, soil borne mosaic virus, barley yellow dwarf virus, powdery mildew, leaf & stem rust, spot blotch, net blotch and more.
  3. Follow the Hessian Fly Free Date: Make all small grains (cover crop or grain) are planted AFTER the Hessian Fly Free Date! Why? Hessian fly is a pest of small grains. The Hessian Fly Free Date is the point that Hessian fly is not active in the fall. The Hessian Fly Free Date indicates when aphids will not be active in the fields. Aphids alone are not a problem but they can transmit barley yellow dwarf disease to the plants.

  1. ALWAYS use certified seed when planting. Certified seed is free from weeds and other diseases.
  2. If planting conventional small grains it is important to use a fungicide on the seed at planting. This will help protect from soil borne fungal diseases.
  3. Good integrated crop management is also important. Soil health, fertility, tillage practices, proper seed bed preparation, planting depth make for a healthy plant that can withstand more pest pressure.

 

Western Bean Cutworm Update 8.18.17

Western bean cutworm trap catches continue to drop significantly from the peak flight recorded the week of August 14. While reports are still coming in, the average WBC / trap average this week dropped to 226 WBC moths / trap down from last week’s average of 170 WBC moths/trap.  Even though the peak moth flight has passed we are still getting a lot of moths. See summary table below for counts at specific locations.

Now that WBC moth numbers are dropping off it is time to begin monitoring fields for signs of WBC larval activity in corn ears. WBC eggs take 5 – 7 days to hatch after which the larvae head to corn ears in the next 10 days. Individual trap catches can vary, even with in a township, based on such factors as local overwintering success and attractiveness of corn stage of development. As trap accumulations approach 100 moths per traps risk of WBC infestation increases and field monitoring for egg masses and young larvae is recommended.

Monitoring WBC in corn ears can be done now and while checking ears for grain maturity. WBC larvae tend to be found towards the ear tip area moving down the ear as they feed. Larger more mature larvae may also bore through the husk or base of the ear. Note that more than 1 WBC may be present at a time compared to a solitary larva per ear more common to infestation by European corn borer, corn ear worm and fall armyworm that may also found in corn ears to time of year. See photos below for examples of WBC in corn ears. Kernel damage caused by WBC feeding can reduce yield and also leaves the ear susceptible to ear infecting fungi including those capable of producing mycotoxins.  Corn containing Cry1F and Vip3a genes have protection against WBC.  Check your seed bag label or the Handy Bt Trait Table (http://msuent.com/assets/pdf/BtTraitTable15March2017.pdf ) for more information.

WBC larva in corn ear tip

Hole created WBCW

  

County Town 6/25/2017 7/2/2017 7/9/2017 7/16/2017 7/23/2017 7/30/2017 8/6/2017 8/13/2017
Cattaraugus Randolph 0 1 4 32 114 36 8 8
Cayuga Aurora 1 2 3 9 23 55 51 41
Clinton Chazy 0 0 0 1 7 24 66 32
Columbia Valatie 0 0 10 20 31 70 18 9
Cortland Scott NA NA NA 2 132 132 104 34
Delaware Davenport NA NA NA 7 67 65 49 NA
Delaware Walton NA NA NA 9 22 42 28 NA
Dutchess Amenia 0 1 5 2 23 11 3 NA
Essex Willsboro 0 0 3 6 9 30 44 38
Franklin Moira NA 0 2 1 4 53 245 252
Franklin Malone NA 0 0 0 6 19 265 921
Franklin Dickinson Center NA 0 0 0 53 4 437 305
Franklin North Lawrence NA 0 2 0 35 113 352 342
Herkimer Little Falls 0 1 1 0 3 23 121 34
Herkimer Mohawk 0 0 0 0 4 7 1 0
Jefferson Calcium NA NA 0 1 4 62 177 178
Jefferson Clayton NA NA 0 0 31 204 183 130
Jefferson Ellisburg NA NA 0 3 119 282 170 28
Jefferson Hounsfield NA NA 0 2 96 233 305 127
Jefferson Pamelia NA NA 0 1 23 173 711 556
Jefferson Philadelphia NA NA 0 1 9 104 193 97
Jefferson Plessis NA NA 3 17 47 149 153 113
Jefferson Rutland NA NA 0 0 0 80 1449 742
Lewis Croghan NA NA 0 4 68 767 695 238
Lewis Denmark NA NA 0 1 1 483 1188 572
Lewis Harrisburg NA NA 6 10 39 319 528 462
Lewis Lowville NA NA 0 5 10 191 242 332
Lewis Martinsburg 0 0 0 0 30 282 533 279
Lewis New Bremen NA NA 0 1 47 192 284 32
Lewis Turin NA NA 0 0 22 308 573 187
Livingston Avon NA 3 4 40 163 114 157 NA
Madison Munnsville NA NA 0 0 9 71 54 NA
Monroe Hamlin NA 0 6 6 192 188 386 NA
Montgomery Canajoharie 2 0 0 1 2 12 8 2
Montgomery Fort Plain 3 2 0 0 3 7 14 2
Niagara Barker NA 0 0 0 68 180 347 NA
Oneida Marcy NA 0 0 2 4 7 11 NA
Oneida munnsville NA 0 1 2 34 36 194 NA
Onondaga Tully 1 0 2 1 20 53 70 11
Ontario Hopewell 0 4 4 48 233 145 239 NA
Schuyler Valois 0 0 1 3 16 16 1 0
Seneca Weedsport NA 1 0 0 10 7 6 NA
St. Lawrence Canton NA NA 0 0 0 79 316 159
St. Lawrence Colton NA NA 0 0 1 45 40 12
St. Lawrence Morristown NA NA 0 0 0 11 101 41
St. Lawrence Madrid NA NA 0 0 1 42 258 48
St.Lawrence Huevelton NA NA 0 0 1 15 68 26
St.Lawrence Waddington NA NA 0 0 0 3 29 95
Suffolk Riverhead 0 0 1 0 0 1 0 0
Tompkins Varna 0 0 2 1 NA 8 0 0
Wanye Walworth NA NA 0 0 146 126 68 NA
Washington Easton 0 0 0 0 3 3 4 NA
7 15 60 239 1985 5682 11547 6485

For additional weekly WBC trap collection information locations see the Sweet Corn Pheromone Trap Network Report http://sweetcorn.nysipm.cornell.edu/ .

A Nebraska entomology prediction model has tied western bean cutworm moth emergence to accumulated degree days using a base temperature of 50 F and a starting date of May 1st.

The moth emergence model is: Degree-day accumulations in relation to percent moth emergence (begin May 1, base 50°F).

 

Accumulated Degree-Days % Moth Emergence
1319 25%
1422 50%
1536 75%

NYS Degree Days

Clipboard Checklist

Keith Waldron, NYS IPM

 General

*Walk fields to check general field condition, weed, vertebrate and other issues

*Watch for crop maturity, stand assessments, weed escapes, nutrient deficiencies, lodging issues

*Update crop records and field history

 

 Alfalfa:

*Evaluate established legume stands for approximate days until harvest
*Monitor potato leafhopper, foliar, systemic and crown rot diseases.
*Monitor new seedings for potato leafhopper, pythium blight, phytopthora root rot.

Small Grains:
*Monitor grain fields for growth stage, disease and lodging issues, grain maturity, harvest timing
*Record diseases present, location and types of weed escapes

* Prepare for planting winter small grains after the Hessian Fly Free Date.

 

Corn:

*Monitor for mid-season corn pests including European corn borer, corn rootworm, western bean cutworm, slugs, foliar diseases such as northern corn leaf blight and gray leaf spot, weed issues, nutrient deficiencies, vertebrate damage.

 

 Soybeans:

*Monitor for growth stage, soybean aphid, defoliators, foliar diseases, white mold, weed issues, vertebrate damage

 

 Pastures:

*Check water sources, mend fences as needed.
*Check crop growth, clip pastures between grazing as needed
*Monitor for invasive species, plants harmful to livestock
*Review/Plan rotations

 

Storage:

* Check stored grain bins for temperature, moisture and signs of mold and insects. Aerate, core, transfer grain or treat as necessary

* Clean and disinfect empty storage bins in preparation for grain harvest
*
Check forage allocation and anticipate feed program adjustments as forages from previous year are used up
*Mow around storage bins and facility to minimize pest hiding places

 

Dairy Cattle Barn Fly Management:

*Monitor animals and barn area for house fly, stable fly and other pest management needs including presence of rodents and birds.
*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 throughout barn
*Use, replenish, replace fly management materials: sticky fly tapes/ribbons, insecticide baits, natural enemies (parasitoids), fly population monitoring (3 x 5) spot cards
*Consider purchase and release of Muscidifurax raptor and/or M. raptorellus natural enemies of house and stable fly pupae.

 

Dairy Cattle on Pasture:

*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 per animal side, 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 exercise yard.
*Check pasture for forage quality / quantity, rotate as appropriate
*Check pasture for vegetation poisonous to livestock
*Consider use of pasture fly traps to help reduce deer, horse and stable fly populations

 

 

 

 

 

Clipboard Checklist

Keith Waldron, NYS IPM

 General

*Walk fields to check general field condition, weed, vertebrate and other issues

*Watch for crop maturity, stand assessments, weed escapes, nutrient deficiencies, lodging issues

 Alfalfa:

*Evaluate established legume stands for approximate days until harvest
*Monitor potato leafhopper, foliar, systemic and crown rot diseases.
*Monitor new seedings for potato leafhopper, pythium blight, phytopthora root rot.

Small Grains:
*Monitor grain fields for growth stage, disease and lodging issues, grain maturity, harvest timing
*Record diseases present, location and types of weed escapes

 Corn:

*Monitor for mid-season corn pests including European corn borer, corn rootworm, western bean cutworm, slugs, foliar diseases such as northern corn leaf blight and gray leaf spot, weed issues, nutrient deficiencies, vertebrate damage.

 

 Soybeans:

*Monitor for soybean aphid, defoliators, foliar diseases, white mold, weed issues, vertebrate damage

 

 Pastures:

*Check water sources, mend fences as needed.
*Check crop growth, clip pastures between grazing as needed
*Monitor for invasive species, plants harmful to livestock
*Review/Plan rotations

 

Storage:

* Check stored grain bins for temperature, moisture and signs of mold and insects. Aerate, core, transfer grain or treat as necessary

* Clean and disinfect empty storage bins in preparation for grain harvest
*
Check forage allocation and anticipate feed program adjustments as forages from previous year are used up
*Mow around storage bins and facility to minimize pest hiding places

 

Dairy Cattle Barn Fly Management:

*Monitor animals and barn area for house fly, stable fly and other pest management needs including presence of rodents and birds.
*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 throughout barn
*Use, replenish, replace fly management materials: sticky fly tapes/ribbons, insecticide baits, natural enemies (parasitoids), fly population monitoring (3 x 5) spot cards
*Consider purchase and release of Muscidifurax raptor and/or M. raptorellus natural enemies of house and stable fly pupae.

 

Dairy Cattle on Pasture:

*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 per animal side, 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 exercise yard.
*Check pasture for forage quality / quantity, rotate as appropriate
*Check pasture for vegetation poisonous to livestock
*Consider use of pasture fly traps to help reduce deer, horse and stable fly populations