May 29, 2015

NYS IPM Weekly Field Crops Pest Report

May 29, 2015: Volume 14  Number 5

 View from the Field

There are many reports this last week of frost damage to emerging corn with temperatures as low as 24 degrees recorded in northern NY. While many young corn fields had symptoms of above ground foliar damage the growing point was fortunately below the soil surface and the corn is expected to recover. The following photo provided by Mike Hunter shows how corn can recover following frost injury to foliage when the growing point is below the ground surface.


There were also a scattering of reports of emerging soybeans with frost damage. Many times soybeans can come back from a frost.

There are reports that hay harvest is behind schedule in many areas. In some cases the grasses are headed out and NDF are not optimum.

Kevin Ganoe (CCE Central NY Dairy and Field Crops Team) suspects that a field of alfalfa has verticillium wilt. Verticillium wilt can be a serious disease, limiting yield and stand life. An early symptom includes a characteristic V-shaped yellow foliar discoloration similar to potato leafhopper (PLH) injury. As the disease progresses, leaflets wilt, turn yellow or pink, and often curl or twist. Stems of infected plants can remain green for long periods of time. Taproots appear healthy and sound, but in cross section appear to have a dark ring indicating damage to the water-conducting tissues, causing wilt symptoms. Verticillium wilt symptoms may be more obvious in the second cutting of alfalfa.

Kevin also reports finding anthracnose in alfalfa.  Anthracnose is a disease that occurs in warm and wet weather.  Stems of infected plants wilt and the stem tips bend over to form a Shepherds crook. Diamond-shaped lesions can appear on the lower parts of the stem about 1-3 inches above the soil line. Anthracnose may advance from infected stems into the crown tissue. The infected crowns appear bluish-black near the base of stems. Plants can appear straw colored and are scattered throughout the field

Mike Stanyard (CCE NW Dairy and Field Crops Team) reports the first black cutworms found in New York. Mike reports that some alfalfa is getting hit hard my alfalfa weevil. Mike also states that many growers are gearing up to spray fungicides to protect from fusarium head blight on wheat and malting barley, With the rains predicted over the next week will increase the risk of this disease. Jon Buckeley reports true armyworm moths were caught this week in pheromone traps in Western NY. We can usually expect some activity of this migratory insect in NY every year. There were no reports of true armyworm damage in New York this week. However, growers are advised to be on the watch for this insect and another migratory pest – black cutworm.

Mike Hunter (CCE Jefferson and Lewis Counties) reports finding alfalfa sclerotinia crown and stem rot. Sclerotinia crown and stem rot usually occurs during cool, moist weather in early spring and late summer. Infected stems become soft and water soaked, the infected plant appears yellow and weak. A characteristic white fluffy mass of mycelium (fungus body) grows over the plants or on the soil surface, infecting new plants as it grows. Seedlings are very vulnerable to this disease. As plants become weak and die, the fungus forms small (1/8 to 1/4 inch), hard black sclerotia (pellet-like balls) on or in the stem or crown tissue. This disease is often associated with fall seedings, seedings into old pastures, or no-till seedings into previous legume sod.

Mike also reports finding fireflies. Fireflies and corn rootworm require a similar number of degree days for their development. When you see fireflies it is likely corn rootworm eggs are hatching in fields.

Paul Cerosaletti (CCE Delaware County) reported finding tiger moth larvae in a cut flower operation. The larvae were feeding on the cut flowers and focused more on Zinnias than other flowers.


Photo provided by Paul Cerosaletti

Weather Outlook – May 28, 2015

Jessica Spaccio (Rennells)

NOAA Northeast Regional Climate Center, Cornell University

Last week temperatures started off below normal with areas of frost and ended above normal; overall the week was 4 degrees below normal to within 2 degrees of normal. Precipitation ranged from zero to 0.4.  Base 50 growing degree-days ranged from 30 to 60. Rain! Some on Thursday, more with a cold front on Sat/Sat night. Today will start mostly cloudy as showers continue to move across the state, a few thunderstorms are possible.  Temperatures will range in the 70’s with low 80’s possible along southern and eastern NY.  Overnight temperatures will be throughout the 50’s. Friday will be mostly sunny and dry with highs in the low to mid 80’s.  Low temperatures will be throughout the 60’s. Saturday will be partly sunny with highs in the mid to upper 80’s for most areas, lower 80’s for southeast NY.  Scattered showers will be possible during the day with showers and thunderstorms likely Saturday night as a strong cold front moves through.  Overnight temperatures will be in the upper 40’s to low 50’s, southeast NY will see low 60’s. Sunday will have lingering scattered showers in the southern areas and much cooler temperatures in the mid 60’s.  Overnight temperatures will be in the upper 40’s to low 50’s; northern NY will see low 40’s.

Maps of 8-14 day outlooks

National Weather Service watch/warnings map

NRCC Drought Page which features the US Drought Monitor map (updated every Thursday)

Pest or Non-Pest in Early Season Corn

Ken Wise, NYS IPM

 While walking corn fields this week I found several early season issues: some pest related and others non-pest problems. The first field I walked was a no-till corn into corn residue. The corn residue was pretty heavy in places of the field. There were skips and small plants among the majority of healthy corn plants. In some cases seed was left on the surface where the planter could not penetrate the previous season’s the corn residue.



Heavy corn residue

 Seed on surface

Seed on the surface under the residue 


As you can see the residue made it difficult for the seeder to get the seed into the soil and left it on the surface. Not too far away was a plant smaller than most of the corn. When the corn residue was pulled away you can see that the corn had germinated on the soil surface.

 Seed Germ surface

Corn Germination on Surface

Make sure the no-till seeder is set correctly for planting into heavy corn residue. I came across 3 identical holes side by side across a leaf.

 bill bug

Maize Bill Bug Damage


This damage is caused by maize billbug. This small (2/5-3/5 inch), nocturnal, reddish brown to black weevil has the characteristic weevil beak-like snout. This minor insect pest (maize billbug) drills through the main stem of the plant. Corn, grasses and sedges are preferred billbug foods. When the plant grows and the leaf unrolls it leaves 2 or 3 holes side by side. Bill bug populations can be associated with high yellow nutsedge infestations. Maize billbug rarely causes economic damage to the corn crop. Watch for potential damage to the corn growing point. Photo of billbug  speaking of yellow nutsedge there was a pocket of it across the field.


Yellow Nutsedge in Corn

 The next pest issue found was deer damage along the edge of the field.

 Deer Damage on Corn

Deer Damage in Corn

 In a field that corn was no-tilled into soybean residue showed a lot of soil crusting and a few problems with corn. The following shows how hard it is for corn seed to emerge from crusted soil.

Soil Crusting

Crusted Soil


 corn custing probelm

Seedling that could not emerge because of soil crusting

 In the same field I found a few plants with seedling blight or damping off. Sometimes the seed may germinate and grow but will die as the plant emerges from the soil. Seeding blights are caused by many of the same fungi that cause seed decay. Seedling blight symptoms include discolored seedling coleoptiles and roots. Seedlings may have a wet, rotted appearance before they reach the soil surface. Above ground symptoms of blight may include seedlings that turn yellow, wilt and die. The use of seed applied fungicides can help control this problem.

Damping off

Damping off in corn


Growing Degree Day ( Base 50, Alfalfa Weevil, Black cutworm)

Ken Wise-NYS IPM

Station Location

Alfalfa Weevil

(Base 48)

March 1

GDDs (Base 50 F) March 1

Black Cutworm

April 15

Ceres 377 311 300
Chazy 402 330 317
Geneva 460 385 382
Highland 582 497 467
Ithaca 411 347 331
Massena 392 321 317
Ripley 462 395 370
Watertown 344 283 275
Wayland 421 352 338

NEWA Growing Degree Days


GDD48_May27                               GDD50_May27

Alfalfa Weevil Degree Days              Base 50 Degree Days

 Clipboard Checklist

Keith Waldron, NYS IPM


*Note and record location of wet/droughty areas on field maps or aerial photo for future tiling considerations and crop decisions, check for areas of soil erosion

*Post-emergence stand counts, weed evaluation

*Watch for early season weeds: winter annuals, chickweed, henbit, field penny cress, shepherd’s purse, giant and common ragweed, purple deadnettle, lambsquarters, redroot pigweed, velvet leaf, Pennsylvania smartweed, common sunflower, quackgrass, foxtail


*Monitor for alfalfa weevil, weevil damage

*Monitor new seedings for Pythium blight and Phytopthora Root Rot.

*Monitor for Alfalfa Snout Beetle (In Oswego, Jefferson, Cayuga, Wayne, Lewis, St. Lawrence, Clinton, Essex, and Franklin counties)

Small Grains:

*Check stands for soilborne virus diseases, Wheat spindle streak mosaic and Soilborne wheat mosaic, check for signs of powdery mildew or other maladies, cereal leaf beetle, weed escapes, goose damage

*Monitor growth stage of development, potential risk of head diseases


*Post-emergence stand counts, weed evaluations, black cutworm, seed corn maggot, wireworm, seedling blights, emergence diseases


*Post-emergence stand counts, weed evaluations, seed corn maggot, seedling blights, emergence diseases


*Check and mend fences as needed.

*Check crop growth, maturity, timing for harvest

*Monitor fields for invasive species, plants harmful to livestock

*Review/Plan rotation system

Dairy Confinement Areas:

*Clean potential house and stable fly breeding habitat: inside barn sanitation: clean / remove spoiled bedding, spilled feed, check water sources for leaks; outside animal exercise / loafing areas / alleyways / feed troughs, feed rings, etc. clean areas of undisturbed moist organic matter such as spilled feed and silage, feed debris around feed troughs and feed rings

*Install sticky tapes, ribbons, monitoring spot cards

*Consider use of insecticide bait stations as needed

*Monitor for stable flies

*Mow around facilities to minimize rodent and other pest habitat

Dairy on pasture:

*Begin monitoring cattle for stable flies, horn flies, face flies