Weekly Field Crops Pest Report 2008
View from the field
Eastern NYS-Ken Wise
You know you live in the Northeast when you have to wear a hat so your balding head does not sunburn one week and the next to cover it from the falling snow! Even though it was cold and snowing at SUNY Cobleskill this week I found alfalfa weevil adults in Julie Hansen’s alfalfa trials. There were not many weevils but the fact it was so cold might mean there were more in the lower canopy. I did not find alfalfa weevil eggs in alfalfa stems but the fact it was cold, blowing and snowing I did not look too closely. (More on alfalfa weevil see the article below.) The alfalfa was 10 to 12 inches tall and looked very good. I did not even see signs of a disease called “spring black stem” as I normally do each year.
Other CCE educators in
Western NYS and the
Keith Waldron reported that clover root curculio and alfalfa weevil adults are present in alfalfa in the
Weather Outlook May 1, 2008
High pressure will move off the east coast on Thursday (today) and a slow moving warm front will essentially stall though northern
Beyond this period there are discrepancies in the different forecast models, however it is unlikely that temperatures will return to above normal levels.
Growing degree day accumulation (base 50 F) since 3/15 has been between 100-150 across upstate.
Will early-planted corn be vulnerable to Seed Decay and Seedling Diseases?
There was a lot of discussion last week as to whether farmers were jumping the gun by getting corn planted on a time frame that seemed extra early. The ground was dry and air temperatures were well above average, so soils were warming. Weather conditions were conducive for early corn planting in many areas of the state at least for a portion of a farm's corn acreage.
One major risk is that early planted corn seed will likely sit in cold soils for awhile before seeds germinate, giving them extra time to be vulnerable to seed decay and seedling rots, in spite of improved seed genetics and traits.
Factors that contribute to both seed decay and seedling blights may include cold (<65oF), wet soils. These unfavorable conditions can lead to slow emergence and slow growth of seedlings. Plant or seed injury from fertilizer burn, incorrect herbicide application, or soil crusting can add to plant stress at the vulnerable seedling stage.
Fortunately, planting high quality corn seed is common practice, and fungicide seed treatments are a normal part of the spring routine for many producers. These practices help prevent many outbreaks of seed decay and seedling blight.
Alfalfa Weevil and Growing Degree Days in NYS
Adult alfalfa weevils are now moving back into established alfalfa fields. Remember alfalfa weevil populations can build up over the life of the alfalfa stand. The longer an alfalfa field is in production the higher the risk of alfalfa weevil damage. Adult weevils that enter fields in the spring are light brown and 3/16" long. They have a band of darker brown down the center of their back and a long snout.
If you keep track of growing degree days you can predict when certain stages of alfalfa weevil development occur. Remember that alfalfa weevil’s base temperature for determining its growth stages by growing degree days is 48 degrees F. You should start scouting and sampling fields at about 350 growing degree days. For more information on alfalfa weevil, view the Alfalfa weevil management guide.
Growing degree Days for peak (50%) Occurrence of Alfalfa Weevil growth stage:
Stage or Event Accumulated growing degree days*
Eggs hatch 280
Instar 1 315
Instar 2 395
Instar 3 470
Instar 4 550
Adult Emergence 815
* 48F base temperature
CURRENT Accumulated Growing degree days (48F Base)
March 1 - April 28th , 2008
Batavia: 218 184
Clifton Park: 338 299
Prattsburg: 167 141
Using NEWA to Determine Growing Degree Days
Our insect pests of field crops depend on accumulations of heat units, or degree days, for their growth and development, given their “cold-blooded” nature. Researchers have extensively studied the biology of some of our key pests in relation to heat accumulation from the environment, and thus we are able to monitor and predict the timing of development of damaging stages. One example of such a pest is the alfalfa weevil.
In past years, we have provided growing degree day accumulation tables for a few locations around
NEWA is NYS IPM’s network for environment and weather awareness. It is a network of electronic weather instruments associated pest forecast models, and radar weather forecasts. Weather and pest data is relevant for farmers across commodities, from field crops to fruit to vegetables. Data available include hourly rainfall, temperature, leaf wetness, relative humidity, and soil temperature readings. All of this information, as well as degree day accumulations are available from almost 50 on-farm locations around NYS, primarily in western NY, the Finger Lakes region, and the
Access to the NEWA home page
Be sure to bookmark this location and check back as often as you need.
Alfalfa Snout Beetles Begin Spring Emergence
Alfalfa Snout Beetle emergence time....
One indication that spring is here is the sighting of newly emerged alfalfa snout beetle populations. Elson Shields (Cornell Entomology) and Joe Lawrence (
Alfalfa snout beetles (ASB) are root-feeding weevils found only in nine northern
ASB adults are mottled gray, humpbacked, 1/2 inch long, do not fly, and are all females. Adult alfalfa snout beetles leave fields void of alfalfa this time of year en mass (by the tens of thousands) in search of new alfalfa fields to lay their eggs. Once they find a suitable location, ASB adults feed on alfalfa foliage and lay eggs that hatch into root feeding larvae. While adult feeding can trim the tops of alfalfa and other hosts, the vast majority of plant death comes from direct root loss caused by ASB larvae feeding.
Alfalfa snout beetle larvae are legless, white, and 1/2 inch long. ASB larvae are found shallow in the soil when very small but move deep in the soil during mid July to late August (18-24 inches). In September the large larvae move back up to the top 8 " and do most of the tap root severing in September and October. After development is completed, they then move deep in the soil to overwinter. Larvae move deep in the soil in the fall after feeding (18-24") and remain there for the next 18 months. Midway through the summer they pupate but remain deep in the soil until the following spring.
ASB damage in the spring looks similar to winter killed alfalfa with plants failing to "green up".Areas of dead alfalfa may also indicate presence of brown rot rot. (See last week's WPR for more information on this disease).
Alfalfa Snout Beetles in your neighborhood? In addition to alfalfa, other host plants for ASB include: red clover, dock, wild carrot, quackgrass, and white clover. ASB control is best achieved with a three year rotation of alfalfa with a row crop. Non hosts, i.e. good crops to have in rotation to minimize ASB losses include: corn, wheat, oats, soybeans, and potatoes. Insecticides are not recommended to control ASB.
More information about ASB, including highlights on two on-going Cornell ASB management research efforts can be found at: http://www.nnyagdev.org/ipm.htm
Soybean Rust Update
Rust continues to be found in the southern
Coordination of soybean rust sentinel plots in
National Soybean Rust Website
*Assess crop for adequate stand and plant vigor
Alfalfa & Hay:
*Monitor alfalfa seedings for weeds, insects & diseases.
*Check established alfalfa stands for over wintering injury, frost heaving, alfalfa weevil, weed and disease problems.
*North country counties: Monitor alfalfa for Alfalfa Snout Beetle (In Oswego, Jefferson, Cayuga, Wayne, Lewis, St. Lawrence, Clinton, Essex, and Franklin counties)
*Timothy stands: check fields for symptoms of cereal rust mite
*Check and mend fences as needed.
*Check crop growth
*Review/Plan rotation system
*Check forage allocation and anticipate feed program adjustments as forages are used up from previous year
*Plan where forages should be stored for optimum allocation for feeding
*Keep areas around storage bins and silos clean and mowed
*Note any repairs needed for corn planter, seeding equipment, alfalfa harvesting equipment, and tillage implements as they are cleaned and lubricated.
*Service corn planter as needed.
Calibrate manure spreaders - maintain records on amount spread per field
PESTICIDE EMERGENCY NUMBERS
Emergency responder information on pesticide spills and accidents
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
Small Grains Field Day
June 5, 2008
Cornell Research Farm at
Julie Dennis: IPM Area Educator, Livestock and Field Crops,
Keith Waldron: NYS Livestock and Field Crops IPM Coordinator
Phone: (315) 787 - 2432
Fax: (315) 787-2360
Phone: (518) 434-1690
Fax: (518) 426-3316