WEATHER
Corn Growing Degree Days (GDD)
GDD average May 1 to today = 270 to 320 across northeast Iowa. It takes corn about 90 to 120 GDD from planting to initial emergence, and about 80 GDD per leaf stage up to V-10 stage.
Plantings and replants May 10-13 show 150 to 115 GDD respectively. Corn should be up.
You can click on the following link to input your planting date for estimated GDD: http://mesonet.agron.iastate.edu/GIS/apps/coop/gsplot.phtml?var=gdd50&year=2012&smonth=5&sday=1&emonth=5&eday=20
Looking for Rain
Everyone is looking for some rain, especially to aid crop emergence. But if you are wondering what regions have received the least precipitation this spring, here’s a current map with the departure from normal: http://mesonet.agron.iastate.edu/data/summary/year/diff.png
CORN & SOYBEANS
Corn Replant
Corn replants are probably complete by now, from the poor emergence of corn planted April 24-27. It appears that around 20,000 acres was replanted in the last week. The worst of this was a band running SW to NE through Floyd and Howard Counties, catching parts of Mitchell, Chickasaw, and Winneshiek Counties. This band received more rain in April than other areas in northeast Iowa (6-8 inches over the last 30 days, see attachment), and some of it rather untimely relative to corn planted April 24-27. ISU Extension has stand assessment information in Table 1 in the May 1, 2012 article at: /CropNews/2012/0501elmore.htm Right now 20,000 plants per acre would be considered a keeper. Current replants should still use full season corn. As we get closer to May 25, we would consider using a shorter day corn. For soybeans, we stay with full season varieties until mid-June.
Scout Emerging Corn & Soybean Fields
With crop emergence comes time for a scouting pass. Check to see that planting operations were accomplished as planned, or is there need to make adjustments for next season. Measure plant population, uniformity of planting depth and plant spacing. Also, scout insects like Black Cutworm, and ID weeds to target with the POST herbicide program.
Plant Population: Count emerged plants in 1/1,000th acre of a row to estimate plants per acre. The length of row to use is different for different row widths. Go to Table 4 on Page 4 for the length of row to use: /Publications/PM1885.pdf
Planting Depth: For corn, check for uniformity of depth. The recommended seeding depth is about 1.75 inches. Planting depth should never be shallower than 1.5 inches. For soybeans, about 1¼ inch depth is a good target.
Plant Spacing: Look for lack of uniformity. Too many standard deviations from normal may results in lower yields. The following article from the University of Wisconsin does a nice job of explaining what a standard deviation is (starting on the bottom of page 2), and also summarizes their research on factors influencing uniformity of corn stands. Go to: http://www.soils.wisc.edu/extension/wcmc/proceedings/5B.rankin.pdf If you want to calculate the standard deviation of part of your corn stand, enter into the following web page the inch-spacings of 20 or so corn plants in a row, then click on “calculate”. http://www.easycalculation.com/statistics/standard-deviation.php Do the same for as many areas of the field that you care to.
Seedling Health: While you check seeding depth, you can also evaluate seedling health. The May 16, 2012 ICM News article by Alison Robertson, ISU Extension Plant Pathologist, discusses this topic. Go to: /CropNews/2012/0516robertson.htm A review of common soybean seedling diseases is at: http://www.ipm.iastate.edu/ipm/icm/2001/5-21-2001/soyseeddis.html Alison Robertson, ISU Plant Pathologist, is interested collecting seedling disease plant samples corn and soybean fields. If you have such a field, please give me a call and I will relay the information to Dr. Robertson.
ALFALFA
First Crop Harvest & Regrowth & Insects
Harvest is well underway. Lately, I have seen more alfalfa weevil in these fields. The harvest process is effective at killing many of these weevils, but sometimes there are enough survivors to feed on the new developing regrowth following harvest. The rule of thumb is that if the field does not green up in 4 to 5 days following harvest, take a close look at the base of the plant and look for weevil. If found, treat the field. See photos and more details at: http://www.ipm.iastate.edu/ipm/icm/node/70 While you are out there, take the sweep net and check for potato leafhopper (PLH). Thresholds are provided in Table 1 at: /CropNews/2009/0615hodgson.htm Early regrowth is the most susceptible to damage. With 4 inches of regrowth, if you take 10 sweeps and catch just 2 PLH, treat the field.
INSECTS
Alfalfa Weevil & Potato Leafhopper
Discussed above under “ALFALFA”
Armyworm – No Reports Yet
No reports yet, but it’s now time to be cautious. Now the much of the winter rye is harvested or killed off, if armyworm were are in these fields, scout as the next planted crop emerges, and take a trip around the edge of the field to see if there is any evidence of armyworm moving to a neighboring field. A 1-page color illustrated tip sheet on Armyworm is available at: /winneshiek/sites/www.extension.iastate.edu/files/winneshiek/First%20Generation%20True%20Armyworm.pdf
Bean Leaf Beetle – First Beans Up
The first soybeans emerged are of the greatest attraction to over-wintering Bean Leaf Beetle (BLB). If the seed was not treated with an insecticide seed treatment, the emerged plants should be scouted. A scouted population of about 2 beetles per seedling plant (VC-V1) would suggest to apply an insecticide. For pest ID and signs of feeding damage, see the following two links: http://www.ipm.iastate.edu/ipm/icm/2006/5-22/beanleafbeetle.html & http://www.ent.iastate.edu/imagegal/coleoptera/beanlb/dscn1254.html
Black Cutworm – Few Reports of Activity
Still very few reports on Black cutworm in corn. Continue scouting until corn reaches V5 stage. The following article includes a link to an Excel spreadsheet for threshold calculations: /CropNews/2012/0425sissonjessehodgson.htm In most cases, threshold will be about 1 to 2% plants cut. A color illustrated tip sheet on scouting for Black cutworm is available at: /winneshiek/sites/www.extension.iastate.edu/files/winneshiek/Scouting%20Tips%20for%20Black%20Cutworm.pdf
Common Stalk Borer – Migrating from Field Borders
Those of you that lose corn plants in the first few rows along grassy field borders may have Common Stalk Borer problems. Go to the following web site for photos of the problem: http://www.ipm.iastate.edu/ipm/icm/2007/6-4/stalkborer.html
For in-field issues. Apply insecticide with "in-field" herbicide program if perennial grasses (quackgrass, wirestem) and ragweed are extensive. If larva are in these weeds when the weeds are killed in spring with postemergence herbicide, the larva are forced to move out of the weed and into something else such as emerged corn.
For field borders. Migration from grassy field borders into the first few rows of corn has begun. A key scouting tip is to look at grass heading-out in the field borders that have pre-maturely dead seed heads. The “dead-heads” indicate Stalk borer presence. A color illustrated scouting tip sheet is available at: /winneshiek/sites/www.extension.iastate.edu/files/winneshiek/CommonStalkBorerScoutingTips5-12-12.pdf
Issue No. 6, Article 7/May 10, 2012
Hop Vine Borer – At Corn Emergence
There are a few fields, or rather spots within fields, in northeast Iowa that have a known history of Hop Vine Borer problems. This insect tends to stay in the same areas of a field year after year. If you have identified this as a pest in a part of a field in the past, the recommendation is to apply a pyrethroid insecticide at initial corn emergence (spike stage). For a photo of Hop Vine Borer larva, go to: http://www.ent.iastate.edu/imagegal/lepidoptera/hvborer/3936.79hopvineb.html For a photo of a trouble spot in a field, go to: http://www.ent.iastate.edu/imagegal/plantpath/corn/hvborer/3936.80hvbdam.html In a field the above ground plant injury looks like wilted or dead plants since this insect tunnels up from below the soil line into the crown of corn plants.
Potato Leafhopper (PLH)
Once first crop alfalfa is harvested, its time scout for PLH. Scouting and threshold information is provided at: /CropNews/2009/0615hodgson.htm Having and using a sweep net (15-inch diameter net) is an excellent investment. If PLH are present, they are easy to kill. The lowest labeled rates work very well on this pest.
OATS
Leaf Diseases
A number of oat fields have shown leaf disease symptoms, many cases since the April frosts. Barley Yellow Dwarf Virus (BYDV) is very common. A bacterial disease called Hallo Blight is less common but found in some fields. I have one unconfirmed report of Rust, and I think I also found some Anthracnose leaf blight. BYDV can be quite serious and is usually managed with resistant varieties. Hallo Blight is usually not that serious with plants likely to grow out of the problem with warmer and drier weather. A review of oats leaf diseases with photos is available at: http://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/prm7780#halo Better photos of Rust and Halo Blight are at: http://www.aces.edu/dept/grain/OatDIS.php Someone asked me if it pays to apply fungicide on these oats. I do not have that data. However, if considering this, here’s a few things to consider. A fungicide will not be effective on BYDV or Halo Blight. Did you seed alfalfa with the oats? If so, then I believe you would be limited to only Headline as a choice since it also carries a label for alfalfa. If the underseeding was alfalfa-grass, then Headline cannot be used. It is not labeled for grass hay.
WEEDS
Nitrogen, Herbicides and Emerging Corn – Repeated from May 7 Crop Notes
Corn has emerged in most fields. For nitrogen and/or herbicide applications on emerged corn, consider: Liquid UAN can be applied over small emerged corn up to around 60-90 lb N/A without causing yield loss, although some burning will occur. However, many herbicide labels do not allow herbicides to be applied using UAN as a carrier after the corn has emerged because of the risk of injury. Be sure to check labels. The following article gives more details on applying UAN and herbicides after corn emergence: http://www.ipm.iastate.edu/ipm/icm/2007/4-23/uan.html
EVENTS
May 23, Pasture Walk Grazing Event, near Giard
1:00 PM start. For details on this event, go to the Pasture-Walk Grazing Schedule for Northeast IA at: /dairyteam/sites/www.extension.iastate.edu/files/dairyteam/PW%202012%20IA%20final%20version.pdf
June 6, Pasture Walk Grazing Event north of Jesup
6:00 PM start. For details on this event, go to the Pasture-Walk Grazing Schedule for Northeast IA at: /dairyteam/sites/www.extension.iastate.edu/files/dairyteam/PW%202012%20IA%20final%20version.pdf
June 6-8, World Pork Expo, Des Moines
Iowa State Fairgrounds. For information, go to: https://www.worldpork.org/ Includes PQA PLUS® and TQA® certification sessions on June 6 at no charge, but you must preregister for these. Space is limited. To preregister, contact Tyler Bettin at IPPA at 800-372-7675 or tbettin@iowapork.org
June 13-14, 4-State Dairy Nutrition & Management Conference, Dubuque
At the Grand River Center. Download a brochure at: http://www.wiagribusiness.org/programs/2012_4state_dairy_nutrition_mgmt_conference.pdf
June 14, Corn on Corn No-Till Field Day, Waverly
11 AM to 2 PM at the Mark Mueller Farm, 1146-220th St., Waverly. For more information, contact the Bremer County Extension office, Ron Lenth or Tammy Curley at 319-882-4275.
Advanced Swine Reproduction Seminar – June 14th
June 14, Advanced Swine Reproduction Seminar, Waverly Civic Center, Waverly
10:00 AM to 3:30 PM, sponsored by ISU Extension, Iowa Pork Industry Center and Iowa Pork Producers Association. Seminar topics include: 1) Dr. Tim Safranski, Swine Specialist, University of Missouri, Management practices and environment of farrowing room which can improve survivability and herd productivity. 2) Dr. Tim Safranski, keys to reach superior reproductive performance. 3) Dr. Rodney Baker, DVM, ISU Vet Diagnostic & Production Animal Med, key factors that influence reproductive health and share management tips with awareness of new technologies that can improve reproductive success. 4) Mark Storlie, ISU Extension Swine Specialist, will review gestation housing consideration for pen group housing vs individual sow house. Two producers will share their observations and experiences. 5) Mark Storlie will also present “Managing gilt development programs for lifetime performance”. There is a registration fee of $30 which includes lunch and materials. The meal will not be guaranteed for those not pre-registered. To register, contact Mark Storlie at the Fayette County Extension office 563-425-3331 or email: mstorlie@iastate.edu
June 15, Ag Professional Tour, ISU Northeast Research Farm, Nashua
9:30 to Noon. Discuss current relevant crop production issues, showcase research trials on the farm, and offer insights into crop management for the 2 months. This program is oriented towards Ag providers, but all are welcome. There is a $10 registration fee. 2.5 CCA credits are offered for an additional $10.
June 19-27, Evaluating Your Estate Plan, 7 locations across Iowa
The Evaluating Your Estate Plan workshop answers estate planning questions and helps prepare for future farm transitions and estate planning. Questions like: Who needs to be involved? What information do I need to gather? When is it the right time to start? Where do I start? How do I decide what to do? Presenters for the workshop have vast experience in ag law and estate planning. The one-day workshop will cover the language of estate planning, gift, estate and inheritance taxes, calculating retirement costs, and many other areas vital to creating a good estate plan. For more information, and the dates and locations of the 7 workshops across Iowa, go to: /article/workshop-offers-estate-plan-options-farm-families
June 21, ISU Southeast Research Farm Field Day, Crawfordsville
Free noon lunch. Program starts at 12:45 pm. This is the 25th Anniversary Celebration of the farm. For more information go to: /Pages/eccrops/meetserc.html
June 23, Breakfast on the Dairy, Dairy Center, Calmar
8:30 AM to Noon at the Northeast Iowa Dairy Foundation, Calmar. This is the 3rd annual Breakfast on the Farm. We'll serve up a great wholesome breakfast and provide guided tram tours of the nationally-recognized Dairy Center. The kids can meet some calves, plus families can visit several exhibits. Come see how Iowa's Dairy Center is growing! The menu includes Dad's Belgian Waffles and sausage along with dairy products produced and processed in NE Iowa. Country View Dairy (Dave Rapson family) is generously supplying yogurt and WW Homestead Dairy is helping to provide cheese curds. Be at the breakfast by 10 AM to see DJs from KOEL and WQPC face off in a cow milking contest. For more information, contact Jennifer Bentley at 563-382-2949 or jbentley@iastate.edu
June 26, ISU Northern Research Farm Field Day, Kanawha
9:00 AM for coffee, program starts at 9:30 AM. Emphasis on corn and soybean management including pests, fertility, and tillage issues.
June 28, ISU Northeast Research Farm Field Day, Nashua
1:00 to 4:00 PM. Details to follow soon. 3 CCA credits available.
Iowa State University Extension and Outreach programs are available to all without regard to race, color, age, religion, national origin, sexual orientation, gender identity, genetic information, sex, marital status, disability, or status as a U.S. veteran. Inquiries can be directed to the Director of Equal Opportunity and Compliance, 3280 Beardshear Hall, (515) 294-7612. Cooperative Extension Service, Iowa State University of Science and Technology, and the United States Department of Agriculture cooperating.