08/26/16

NYS IPM  Weekly Field Crops Pest Report, August 26, 2016

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Volume 15  Number 17

 

Pasture Fly IPM/Rotational Grazing/Pasture Soil Health Meeting in Essex County

Date:               September 10, 2016

Time:               2:00 pm to 4:00 pm

Location:         Gillilland Farm,

444 Mountain View Drive, Willsboro, NY

To register please email or call Anita Deming

Email: anitademing@cornell.edu

Phone: 518-962-4810 x409

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View from the Field

Spider Mites on Soybeans

Mike Stanyard (CCE Northwest NY Dairy and Field Crops Team) reports that spider mites on soybeans have been a problem for some farmers that still have drought conditions. In a few cases the farmers had to sprayed their soybean fields with a miticide. For more information see the following article:  Two-Spotted Spider Mites in Soybeans

Spider mites on soybeans-Photo by Mike Stanyard

Spider mites on soybeans-Photo by Mike Stanyard

Stalk Rots on Corn

At a field corn meeting this week we found some lodged corn that might be the start of stalk rot. The plants were lodging right at the soil surface. When you cut the stalk open as it enters the root system the pith was starting to turn light brown. See article below on stalk rots in field corn.

Gray Leaf Spot on Corn

There have been reports of gray leaf spot starting to show up in field corn in the Hudson Valley. The good thing is that many of the infections have started too late to cause yield losses. Cercospora zeae-maydis is the fungus that causes the disease.

Identification

  1. Early symptoms are yellow to tan lesions with a faint watery halo.
  2. As the lesion progresses it turns brown and rectangular in shape that exist between the distances of the veins.
  3. When fully developed the lesion can be 3 to 4 inches long and a 1/6 to 1/8 inch wide.
  4. The fungus can overwinter on corn debris left on the soil surface.
  5. Spores develop when it starts getting warm and the humidity started to rise in late spring.
  6. The spores can be transmitted by both wind and rain.
  7. In some cases gray leaf spot can limit yield up to 5 to 40 bushels of corn per acre.
Gray Leaf Spot on Corn

Gray Leaf Spot on Corn

Management of Gray Leaf Spot

  1. Select corn hybrid with at least moderated resistance to gray leaf spot.
  2. Crop rotation and tillage is an effective method to control the fungus.
  3. If you maintain no tillage or reduced tillage rotation away from corn 2 years can help control the fungus.
  4. If the corn has gray leaf spot use of a fungicide is available to the fungus.

When is it time to spray for gray leaf spot?

  1. You have to have an infection that exceeds 5% of the plant leaf area
  2. The field is with 2 weeks before or after the VT growth stage. If lesions develop later in the season economic impacts from using a fungicide will be less.
  3. Lesions should be on leaves at or above the corn ear.
  4. You can also factor the needed increase in bushels/acre to break even on an application of fungicide. See table below

 

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Source: Gary Bergstrom- Cornell University

Weather Outlook – August 25, 2016

Samantha Borisoff

NOAA Northeast Regional Climate Center, Cornell University

Last week temperatures ranged from near normal to more than 4 degrees above normal in parts of western and southeastern New York. Precipitation ranged from ¼ inch in parts of western New York to more than 4.5 inches in parts of eastern Long Island. Base 50 growing degree-days ranged from less than 80 in the Adirondacks to more than 160 in parts of southeastern New York.

A cold front sparks some showers Thursday, followed by dry, sunny conditions for the weekend.

Today expect a chance of showers and thunderstorms. Some rainfall could be heavy. Temperatures will be in the upper 70’s to upper 80’s. Overnight lows will be in the mid 60’s to mid 70’s.

Friday will feature some morning showers, mainly in the eastern half of the state. Otherwise, the day will be mostly to partly sunny with highs ranging from near 80 to near 90 degrees. Lows will be in the mid 50’s to mid 60’s for much of the state.

Saturday temperatures will be in the upper 70’s to upper 80’s, with mostly sunny skies. Overnight temperatures will be in the mid 50’s to mid 60’s for most areas.

Sunday highs will also be in the upper 70’s to upper 80’s. Expect mostly to partly sunny skies for much of the day, with a slight chance of showers late in northern and western New York. Overnight temperatures will be in the 60’s.

Monday expect partly to mostly cloudy skies with a chance showers and thunderstorms as a cold front slowly moves across the state. Highs will be in the upper 70’s to upper 80’s. Lows will be in the upper 50’s to upper 60s.

Tuesday morning there could be some lingering sprinkles in southeastern parts of the state. Otherwise, skies will be partly cloudy. Temperatures will be in the mid 70’s to mid 80’s.  Lows will be in the upper 50s to mid 60s.

Wednesday temperatures will be in the mid 70’s to mid 80’s, with mostly to partly sunny skies. Lows will be in the upper 50s to mid 60s.

The five-day precipitation amounts (Aug 25-30) will range from less than 1/10” in southeastern New York up to 1.25” in parts of central and southwestern New York.

The 8-14 day outlook (August 31-September 6) shows increased chances for above normal temperatures and above normal precipitation for the entire state.

The September outlook shows no indication for above or below normal temperatures or precipitation.

The September/October/November outlook shows increased chances for above normal temperatures. There is no indication for precipitation.

The Drought Monitor: While the state did receive some rain during the past week, there was not enough precipitation to make much of a dent in drought conditions. The Drought Monitor released on August 25 shows similar conditions to last week, with 45% of the state in a drought and 41% of the state abnormally dry.

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

 base 50 since mar1

Stalk Rots in Field Corn?

Ken Wise, NYS IPM

 Stalk rots are normally a complex of different diseases and factors working in the corn plants. Many times stalk rots occur when you have multiple stresses on the corn plants at the same time over the course of the growing season. This could be the combination of environmental factors, soil nutrition, diseases, insect pests, available moisture and more. When a plant is stressed in more ways than one it is more vulnerable to diseases like stalk rots. There are many different fungi and bacteria that can cause stalk rots. Many of these diseases can survive on past corn crop residue or even in the soil. Stalk rots normally enter the plant through the roots but can enter other ways like insect pests boring into the stalk leaving an open hole for pathogens to enter the plant through wind or rain. Stalk rot causes premature death of the corn plant by attacking water conducting tissues of the roots and lower stalks. As it progresses the fungi moves up the pith of the plant. The cells in the pith of the plant are thinner and much easier for the disease to attack than from the outside. This limits the plant from moving water and nutrients. The rot will weaken the stalks and plants can start to lodge. While each species of stalk rots have specific symptoms they do have a few that are in common.

  1. Leaves may be wilted or roll and start to turn brown.
  2. An entire field may appear to be killed by a frost because the disease does not allow water and nutrients to move through the plant
  3. Lesions will appear on lower nodes and/or on entire stalk
  4. Stalks become soft (healthy stalks are firm). With advance stages of rot the stalk can be easily crushed with your fore finger and thumb.
  5. Stalks can lodge with a weather event.

 

The following are specific types of stalk rots found in NYS:

Common Name/Species Symptoms Link to photos
Anthracnose stalk rot/ Colletotrichum graminicola Symptoms often show after tasselling as vertical, tan to reddish brown, water-soaked lesions (streaks) in the stalk rind. Lesions become large and dark brown to shiny black. If you see anthracnose leaf blight, check for anthracnose stalk rot—both diseases share the same causal agent.

Anthracnose stalk rot

 

Diplodia stalk rot/ Stenocarpella maydis Symptoms appear as numerous black pycnidia (a saclike spore case) in the lower internodes of the stalk. The cases are black dots size of a pinhead or smaller. Look for a white mold on the stalks when weather is wet Diplodia stalk rot
Fusarium stalk rot/ Fusarium spp. This disease normally starts just after pollination, with symptoms appearing later in the season. When you cut open the stalk, the pith shows as a whitish to pink (salmon) color. Look also for distinctive brown streaks on the lower internodes.

Fusarium stalk rot

 

Gibberella stalk rot/ Gibberella zeae This disease shows first as leaves fade to a grayish-green. Stalks turn dark green to tan near their bases. The pith softens, turning reddish or pink Gibberella stalk rot
Pythium stalk rot/ Pythium aphanidermatum This disease 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.

Pythium stalk rot

 

 

There are management practices you can do to limit corn stalk rots in your fields.

  1. Plant hybrids that are resistant to the diseases. Remember that corn can be resistant but never immune.
  2. Use of crop rotation is a good way to limit the diseases from infecting the corn. Many of these diseases survive on corn residue. By planting corn in the same field each year you increase the risk of getting an infection.
  3. Use proper plant populations. If a field is planted at too high of a population the corn will compete for nutrients and water. This adds more stress to the plant and an increased risk of getting an infection.
  4. Maintain good soil fertility and pH. By maintaining good soil fertility and pH helps keep corn plants healthy and reduces stress on the plants.
  5. Proper cultivation. If you cultivate, it is important not to damage the roots or the plants. If they are damaged it increase the pathways for disease to infect the plants.
  6. Tillage can help reduce the available disease in the field by burying residue. While tillage can help it is not a guarantee control. Plus the need to reduce erosion and save on soil moisture maybe more important.

Western Bean Cutworm Update 8.26.16

Western bean cutworm trap catches continue trickle in this week with more reports of empty traps. While reports are still coming in, the average WBC / trap average this week dropped to 6.5 WBC moths / trap down from the 7/31/16 average of 101 WBC moths/trap.  See summary table below for counts at specific locations. See last week’s WPR for more information on sampling for WBC larvae.

6/26 7/3 7/10 7/17 7/24 7/31 8/7 8/14 8/21
                 
Traps Reporting 30 54 64 67 67 67 66 56 55
WBC Total 1 17 90 777 3601 6785 4308 996 356
Avg WBC / Trap 0.0 0.3 1.4 11.6 53.7 101.3 65.3 17.8 6.5
“0” WBC 29 40 36 12 4 6 5 8 17
> 0 WBC 1 14 28 55 63 61 61 48 38
% Traps Catching 3.3% 25.9% 43.8% 82.1% 94.0% 91.0% 92.4% 85.7% 69.1%
Season Totals 1 18 108 885 4541 11393 15701 16697 15701

 

County Town 6/26 7/3 7/10 7/17 7/24 7/31 8/7 8/14 8/21
Cattaraugus Randolph 0 0 11 19 55 67 NA NA NA
Cattaraugus South Dayton     1 34 69 56 NA NA NA
Cayuga Aurora 0 0 1 12 14 23 7 3 3
Clinton Chazy 0 0 1 2 4 12 12 3 2
Columbia Valatie 0 1 7 4 2 9 10 10 0
Delaware Davenport 0 0 1 0 26 2 3 3 1
Delaware Walton 0 0 0 0 16 9 2 0 0
Dutchess Amenia 0 0 0 0 4 7 1 0 0
Dutchess Amenia 1 0 4 4 8 6 7 1 0
Essex Willsboro 0 3 4 3 3 0 3 1 1
Franklin Chateaugay     0 2 0 44 133 89 36
Franklin Malone     0 1 9 467 911 206 43
Franklin Dickinson  Center     0 1 54 261 354 69 13
Franklin Moira     0 6 101 167 193 39 11
Genesee Stafford 0 0 1 10 77 60 32 8 5
Jefferson Calcium   0 0 12 141 106 83 29 14
Jefferson Chaumont   0 2 49 28 48 6 6 0
Jefferson Clayton   0 0 21 328 410 29 19 5
Jefferson Ellisburg   0 2 62 115 281 49 6 2
Jefferson Hounsfield   1 0 46 434 346 56 20 25
Jefferson Pamelia   0 2 20 141 217 86 9 9
Jefferson Philadelphia   0 9 19 156 190 158 21 10
Jefferson Plessis   0 0 21 38 44 23 7 9
Jefferson Rodman   1 2 4 69 82 18 8 14
Jefferson Rutland   1 0 2 19 362 97 54 18
Jefferson Watertown   0 3 20 86 252 113 37 42
Lewis Croghan-h   0 0 4 74 128 39 8 2
Lewis Croghan-p   0 0 3 42 133 18 12 2
Lewis Denmark   0 0 0 38 211 43 11 7
Lewis Harrisburg   1 0 4 37 115 55 21 2
Lewis Lowville   0 0 0 8 118 32 8 3
Lewis Lowville   0 1 3 111 78 59 15 19
Lewis Martinsburg   0 0 2 32 222 365 20 6
Lewis New Bremen   0 0 2 53 61 21 5 2
Lewis Turin   0 1 1 47 94 37 6 4
Livingston S Caledonia 0 1 2 13 59 41 7 6 0
Livingston SW Caledonia 0 0 3 10 69 64 15 5 0
Livingston Groveland 0 0 0 0 31 102 79 34 9
Madison Munnsville   0 0 4 7 24 29 NA 0
Monroe Riga 0 1 24 148 215 193 45 24 2
Monroe Hamlin   0 1 6 61 123 70 7 NA
Niagara Barker 0 0 0 12 70 99 224 16 NA
Oneida Clinton 0 0 0 1 0 0 0 0 0
Onondaga Tully 0 0 0 7 23 33 14 0 0
Ontario Geneva 0 0 0 9 34 71 31 0 2
Schuyler Valois 0 0 2 18 23 0 6 2 0
Seneca Seneca Falls   0 0 1 17 33 17 4 NA
Seneca Weedsport 0 0 0 0 0 0 0 0 0
St. Lawrence South Colton     1 2 15 50 55 5 2
St. Lawrence North Lawrence     0 6 132 316 121 55 12
St. Lawrence Chase Mills       4 9 31 14 0 0
St. Lawrence Madrid     0 0 123 261 111 4 0
St.Lawrence Huevelton     1 4 12 32 24 12 0
St.Lawrence Hammond       0 9 82 21 21 3
St.Lawrence Edwards     0 0 8 62 35 30 2
Steuben Howard       2 0 2 15 NA NA
Steuben Howard Hill 0 1 1 0 5 65 0 NA NA
Steuben Avoca 0 1 0 10 14 107 35 NA NA
Steuben Cohocton Hill 0 0 0 1 8 2 15 NA NA
Steuben Cohocton  0 2 0 1 4 7 0 NA NA
Steuben North Cohcoton 0 0 4 4 6 95 39 NA NA
Steuben Wayland 0 0 0 5 7 20 10 NA NA
Steuben Dansville 0 1 0 0 2 29 46 NA NA
Suffolk Riverhead 0 0 0 3 1 0 0 0 0
Tompkins Varna 0 1 2 7 17 0 12 7 3
Washington Easton 0 1 1 17 17 54 34 4 0
Wyoming Attica 0 0 6 59 144 144 98 6 4
Wyoming Wyoming   0 0 49 75 22 31 NA 7
    1 17 90 777 3656 6852 4308 996 356

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%

 base 50 since may1

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