Volume 16- Number 4
View from the Field
Mike Hunter (CCE Northern New York) and Aaron Gabriel (CCE Capital District) report finding small armyworm larvae in grass hay. Mike stated that larvae were relative easy to find. We are still catching armyworm moths in pheromone traps across the state. It is time to get our and check for the armyworm larvae. In hay fields they will most like be right at the soil surface during the day. Just move back the grass and residue on the surface and look for them.
Aaron also found sawfly larvae that look similar to true armyworm. Here is a link his Facebook work page. https://www.facebook.com/aaron.gabriel.5437 . The posting was on May 25th.
Here are signs of true armyworm damage to field corn.
For more information on true armyworm see the following article. http://blogs.cornell.edu/ipmwpr/page/3/#True_Armyworm_aka_Common_armyworm
Mike Stanyard (CCE Northwest Dairy and Field Crops Team) reports finding cereal leaf beetle eggs and larvae in malting barley. Here is an article for more information on cereal leaf beetle:
Photo by Mike Stanyard (CCE Northwest Dairy and Field Crops Team)
Gary Bergstrom (Cornell University Extension Plant Pathology, Professor) stresses that fusarium head blight is a risk. See article below.
Weather Outlook – May 25, 2017
NOAA Northeast Regional Climate Center, Cornell University
Last week temperatures ranged from 2 to 6 degrees above normal. Precipitation ranged from a trace to 1 inch. Base 50 growing degree-days ranged from 40 to 100.
Low-pressure system brings cooler temps & rain Thursday into Friday, Saturday is dry before unsettled weather returns…
Today will be cooler than normal with highs in the upper 50’s to low 60’s as a low-pressure system moves in. This will also bring rain and showers to the state. Overnight lows will be range from the mid 40’s to mid 50’s.
Friday’s highs will range throughout the 60’s with lingering scattered showers, especially in eastern areas. Lows will be in the mid 40’s to mid 50’s.
Saturday will be partly sunny with highs in the 70’s. Overnight temperatures will be in the upper 40’s to mid 50’s.
Sunday, highs will again be in the 70’s, but with a chance of scattered showers. Overnight temperatures will be in the 50’s.
Monday’s highs will be in the low to mid 70’s with a chance of showers. Lows will be in the 50’s.
Tuesday will have temperatures in mid 60’s to mid 70’s with a continued chance of showers. Lows will be in the 50’s.
Wednesday, temperatures will be in the mid 60’s to mid 70’s, again with a chance of showers. Lows will be in the 50’s.
The seven-day precipitation amounts will range from ¾ “ to near 2.1”. Thursday and Friday’s rain will total ¼ “ to near 1”. Sunday and Monday’s rain will range from ¼ “ to 1.31”.
The 8-14 day outlook (June 1-7) favors near-normal temperatures and precipitation.
Fusarium head blight commentary, May 26, 2017:
Gary Bergstrom, Extension Plant Pathologist, Cornell University
Most winter malting barley fields in New York have headed out and the remainder will do so this week. Foliar sprays of Caramba or Prosaro up to seven days after head emergence may still result in significant FHB and DON suppression. Fungicide products containing strobilurins should not be applied to headed wheat or barley as they may result in increased levels of DON in grain. A heads emerged spray with these triazole fungicides also helps protect upper leaves against fungal leaf blotches, powdery mildew, and rust. Even though we have had frequent rains, the Fusarium Risk Assessment Map shows mostly low risk of Fusarium infection in New York because temperatures have been considered too low for spore production.
This is a critical week ahead for fungicide spray decisions on winter wheat. Winter wheat in New York varies from boot stage to the initiation of flowering. The triazole products Caramba and Prosaro are the most effective fungicides for suppression of FHB and DON contamination when applied at flowering (emergence of anthers on heads). A flowering application of triazole fungicide should be based on Fusarium head blight (FHB) risk as well as the risks of powdery mildew, rusts, and fungal leaf blotches in the upper canopy based on scouting of individual fields. We have observed low levels of powdery mildew and fungal leaf blotches. We confirmed the first stripe rust of the season today on winter wheat in Yates Co.! Foci were fairly large with severe rust in the lower canopy spreading to upper leaves, suggesting a number of rust reproduction cycles in these fields and possible local overwintering of the rust. There is an application window of approximately 7 days from the beginning of flowering in which reasonable FHB suppression can be expected. Check the Fusarium Risk Assessment Tool (http://www.wheatscab.psu.edu/) and your local weather forecast frequently as your winter wheat crop approaches heading and flowering.
Barn Flies? – Early Season Efforts Will Pay Off!
Keith Waldron NYS IPM
Barn Flies? Given the right conditions barns and other livestock facilities can offer great habitats to develop house and stable fly populations. The good news is that early intervention can help minimize 90% or so of the potential fly problem. A little management time each week will pay big dividends as the season progresses. The two most common fly species found in barn areas are the house fly and stable fly. Both fly species prefer to lay their eggs in moist, not wet, moist decaying organic matter such as spilled feed, moist hay, wet grain, and straw bedding. These areas are great habitats for maggots to develop leading to populations of these nuisance flies.
Keeping potential fly breeding habitat dry will minimize their attractiveness and suitability for house and stable fly populations find refuge and increase. House and stable flies are cold-blooded meaning their activity is greatly affected by temperature. Cooler temperatures slow down fly population development. For example, when temperatures average 68 F the house fly can grow from egg to adult in 18-21 days. At higher temperatures, say 86 F, development speeds up considerably, taking only 9 – 11 days to go from egg to an adult fly. Take home message? If fly breeding conditions are favorable and it get’s warmer, the fly situation on farms can change quickly and dramatically. Here are a few tips to help avoid fly population surprises and potential problems.
Keep it dry. Check water sources for leakage, if water buckets are used with animals, such as in calf pens or holding areas, empty water buckets outside. Our weather has been dry lately but after rains, check rain gutters and outside water diversions for effectiveness. Clean feed spills around outside feeding rings and feed troughs. Left undisturbed these areas can be ideal stable and house fly breeding areas
Sanitation, Sanitation, Sanitation! Staying ahead of fly populations begins with cultural practices that eliminate conditions favorable to fly breeding. House flies and stable flies both breed in areas where moist undisturbed organic matter such as spilled feed and manure-soiled bedding are present. Another favorable breeding spot is a location that remains relatively undisturbed and offers protection from foot and hoof traffic. Frequent clean out of these favorable breeding habitats and other activities that enhance dry conditions in animal areas will make the local environment inhospitable to successful buildup of fly populations. Removing fly breeding habitat frequently, daily if possible, or at least once or twice a week at a minimum. With dry conditions and sound sanitation as the foundation for fly management, additional tactics can be brought to bear.
Choice of animal bedding material. Studies have shown moist undisturbed straw is a very good medium for production of house and stable flies. Where possible avoid straw for animal bedding during the summer fly season. Substituting sand, gravel, wood chips/shavings, sawdust or other materials for straw bedding has been shown to significantly reduce house and stable fly maggot populations when compared to straw bedding under the same conditions. Also note: The more animal bedding can stay dry, i.e. better drainage and frequent changing, the less hospitable it is for a fly population to develop.
Protect Natural Enemies. A variety of biological control agents occur naturally in the typical dairy barn. These include various predators of house and stable fly eggs, larvae and adults. When sanitation, is used effectively, natural enemies can more easily keep up with remaining fly populations and can be quite effective at reducing their numbers. The key is to employ sound sanitation, early and as often as practical, as the first line of defense for mitigating fly populations. Common fly predators include predaceous mites, rove and Carcinops beetles, parasitoid wasps, and fly diseases. Fly parasitoids, small wasps that attack fly pupae, are quite effective at reducing fly populations. These tiny wasps do not attack animals or humans. The fly parasitoids can, however, take up to three times longer to develop than the house fly. For this reason their populations can use a “jump start” early in the season to reach the numbers needed to head off house fly problems. Those wishing to use parasitoids to enhance their biological control efforts should begin parasitoid releases early in the season – mid to late May is recommended. There is still time to begin releasing the wasps in barns and calf housing areas. Parasitoids should be released close to their prey, i.e. in and around potential fly breeding habitats. Cornell research has shown the dairy fly parasitoids (Muscidifurax raptor and Musicifurax raptorellus) to be the most effective fly predators for use in dairy facilities in New York. Reducing the number of adult (breeding) flies helps minimize the potential for fly population buildup.
Sticky Situations. Two additional fly management tactics to curb fly numbers include use of sticky ribbons, tapes, fly string on a reel and insecticide baits. Sticky ribbons (including the wide roll types) and tapes on a reel offer an effective non-toxic means to capture adult flies. Place sticky tapes in areas not at risk from high winds, turbulent air and dusty conditions. Insecticide: sugar bait stations can also be deployed to capture and kill adult flies. Each female house fly can produce up to 600 eggs. Each stable fly female produces up to 400 eggs. Reducing the breeding fly population can pay big dividends!
For more information on IPM for barn fly management see: IPM for Livestock (http://www.nysipm.cornell.edu/livestock/), Integrated Management of Flies in and around Dairy and Livestock Barns (https://www.youtube.com/playlist?list=PLC307D9A62CA393C8) and Integrated Pest Management Guide for Organic Dairies (http://hdl.handle.net/1813/42899)
Early Season Foliar Diseases of Small Grains
Ken Wise, NYS IPM
Spring is the time to look for certain foliar diseases you may encounter on your winter wheat. These are powdery mildew, stagonospora nodorum blotch, and wheat rusts. You normally start to see this in late April or May. It is best to get out and scout your fields now! Here is what you will want to look for:
Powdery mildew forms a white to gray, fungal coating on the above-ground parts of the wheat plant. Lower leaves are usually the most severely infected because of the high humidity in the lower canopy. As disease lesions age small black fruiting bodies (cleistothecia) develop with in white infected areas. Powdery mildew is favored by wet and humid days with moderate temperatures of 600 F or above. Powdery mildew is disseminated by airborne spores.
Stagonospora Nodorum Blotch
Symptoms usually appear within two or three weeks of head emergence. Leaf lesions begin as very dark brown flecks or spots, sometimes with a yellow halo. These small irregular lesions expand into oval light brown lesions with dark brown centers. On wheat heads the lesions begin as either grayish or brownish spots on the chaff, usually on the upper third of the glume. As lesions enlarge, they become dark brown and the centers turn grayish-white in color as tiny brown or black dots (pycnidia) develop within them. Splashing rain or thunderstorms can move spores from field surface to the plant. Wheat seed can be infected from spores when it is harvested. This disease may also be in the wheat residue on the surface of the field.
Rust lesions are small, circular, and vivid orange in color. They may occur on stems, but are most common on the upper surface of leaves. Leaf rust can develop very rapidly so it should be treated as soon as possible. Leaf rust is favored by warm and humid weather with thunderstorms in June. Leaf rust is disseminated on winds which carry the airborne spores great distances. Temperatures between 600 and 800 F are optimal for disease development.
Monitoring the fields
Scout and assess upper three leaves for symptoms and signs of these three diseases in early to mid-May through June, before flag leaf emergence. If disease (any amount) is observed on approximately 50 percent of main tillers that averaged across the field, a fungicide should be considered now.
Table 1: Management Options
Management Practice Powdery Mildew Stagonospora Nodorum Blotch Leaf Rust
Certified Seed — 2 —
Timely Planting — — 2
Fungicide Seed Treatment 1 3 —
Host Plant Resistance 2 — —
Rotation 2 1 —
Fungicide Application 1 2 2
-Control Measures and Their Effectiveness (1=high to 3=slight)
Source: Purdue University Field Crops IPM Handbook
If a field is over threshold for one of these three foliar diseases the next step is to go through an analysis of whether a fungicide application is an economic option. Please follow the steps listed below to determine if a field might need an application of fungicide.
Guidelines for Wheat Fungicide Decisions
(Taken from Cornell Guide for Integrated Field Crop Management)
Does the crop have a reasonable yield potential?
Assess the crop in early May (stem elongation stages) for adequate stand (density of approximately 30 strong stems per foot of row for 7-inch rows on good soils) and plant vigor. If the stand is sparse or plants are not vigorous or show widespread symptoms, fungicide application should not be considered further.
____ Yes ___ No
Have foliar diseases been observed before flag (last) leaf emergence?
Assess upper three leaves for symptoms and signs of powdery mildew, leaf spots, or leaf rust in early to mid-May, before flag leaf emergence. If disease (any amount) is observed on approximately 50 percent of main tillers, averaged across the field, a spray should be considered now. This threshold is exceeded in less than 50 percent of location/year situations in New York, so there is a significant risk of making an unnecessary fungicide application.
____ Yes ___ No
Have foliar diseases been observed during head emergence?
Assess upper two leaves for foliar diseases in late May to early June; if disease (any amount) is observed on approximately 50 percent of main tillers, a spray should be considered now. Fungicide applications made after early June may control some diseases but are unlikely to produce significant yield benefits.
___ Yes ___ No
Are climatic predictions conducive for further disease development?
Powdery mildew development is reduced dramatically once the average daily temperature rises above 70˚F; this disease often disappears by June. Severe leaf spot development is favored by extended periods of wet weather; it may be insignificant if dry weather persists in May and June. Listen for regional advisories on the threat from leaf rust; rust inoculum often builds up in areas to the south and west of New York and is deposited here by thunderstorms in June or July. In addition to disease observations, use long-range local weather forecasts in making your spray decision.
What is your short to medium term weather conditions?
Have I selected fungicides appropriate for the disease spectrum and have I read the label carefully?
Be sure that the materials you spray will be effective against the range of diseases found in your field; e.g., some products effective against powdery mildew are ineffective against leaf spots or vice versa. Cornell University Guide for Integrated Crop Management: https://demo.cuguidelines.net/.
Is the spray decision consistent with my perception of risk?
A simple formula for evaluating the relative economics of a fungicide spray is: Relative Profit = (Grain Yield Increase x Grain Price) – (Cost of Fungicide + Application Costs). If ground spray rigs are used, the yield lost to wheel traffic should also be factored in. Each of these variables influences the relative economics of fungicide application as illustrated in the Cornell University Guide for Cornell University Guide for Integrated Crop Management: https://demo.cuguidelines.net/.
Relative Profit = (Grain Yield Increase _____ x Grain Price _____) – (Cost of Fungicide _____ + Application Costs ________)
Black Cutworm Moth Captures
True Armyworm Moth Captures
Field Crops Insect Pest Degree Days
Growing degree Days for peak (50%) Occurrence of Alfalfa Weevil growth stage:
(Note: for alfalfa weevil predictions use Base Temp of 48F)
Seed Corn Maggot Peak Flight and Fly Maggot Free Degree Days
|Base Temp = 390 F||Peak 1st Generation||Seed corn maggot fly free degree days||Peak 2nd Generation||Seed Corn maggot fly free degree days||Peak 3rd Generation||Seed Corn Maggot fly Free degree days|
Source: Insect IPM for Organic Field Crops: Seed Corn Maggot by Katelin Holm and Eileen Cullen
Black Cutworm Degree Days
Degree Days Stage Feeding Activity
0 Moth Capture Egg Laying
90 Eggs Hatch
91-311 1st to 3rd Instar Leaf Feeding
312-364 4th Instar Cutting Begins
365-430 5th Instar Cutting Begins
431-640 6th Instar Cutting Slows
641-989 Pupa No feeding
Source: University of Minnesota Black Cutworm Trapping Network
2017 New York Field Crop Pest Degree Day Accumulations for selected locations
GDDs (Base 50 F)
Seed Corn Maggot (base 39)
Black Cutworm (Base 50)
Base 50 F degree days
Alfalfa Weevil Base 48 F degree days
Maps provided by Jessica Spaccio at the NE Climate Center
Keith Waldron, NYS IPM
*Pre- and post-plant weed evaluation, timing cultivation and/or post-emergent weed management
*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
*Evaluate established legume stands for harvest.
*Monitor for alfalfa weevil, crown or foliar diseases
*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)
*Monitor winter grain fields for growth stage, disease presence or risk, weed issues (such as winter annuals, corn chamomile and chickweed), growth stage, number of tillers
* Evaluate stands for risk of fungal diseases (See above Dr. Bergstrom’s article above)
*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
*Plant corn as conditions allow
*Pre- and post-plant weed evaluation, timing cultivation and/or pre- and post-plant weed management
*Emergence: assess stand, population count, bird and early season insect issues e.g. black cutworm, wireworm, white grubs.
*Plant soybeans as conditions allow
*Pre- and post-plant weed evaluation, timing cultivation and/or post emergence weed management
*Emergence: assess stand, population count
*Check and mend fences as needed.
*Check crop growth
*Monitor fields for invasive species, plants harmful to livestock
*Review/Plan rotation system
*Remove / clean soil and crop debris from equipment
*Arrange for custom weed control or check your own application or cultivator equipment for repairs.
*Carry appropriate / necessary NYS DEC and EPA required documents: (pesticide applicators license, pesticide labels, MSDS sheets, etc.) with application equipment
-planting equipment – maintain records on planting rate per field
-manure spreaders – maintain records on amount spread per field
-pesticide application equipment – Check nozzles, pumps, etc., recalibrate pesticide application equipment before use.
* Check stored grain bins for temperature, moisture and signs of mold and insects. Aerate, core, transfer grain or treat as necessary
*Check forage allocation and anticipate feed program adjustments as forages from previous year are used up
*Plan where forages should be stored for optimum allocation next feeding season