Verify Wheat Growth Stage Before Applying Growth Regulator Herbicides

Poor wheat stands caused by late planting, decreased tillering, and winterkill have many growers contemplating herbicides in 2009. Make sure you properly growth stage your wheat before applying dicamba or 2,4-D. The mid September and early October planted wheat crop is at or nearing the Feekes 4-5 or Zadoks 30 growth stage (pseudostem erection or hollow stem) (Image 1.). After this stage and when wheat has a visible joint (Feekes 6), wheat can be very sensitive to dicamba and 2,4-D herbicides. Last year we had several reports of 80 bushel wheat dropping to 20 bushel wheat when dicamba was applied at Feekes 6. After jointing there are several other herbicides that can be safely used. Please refer to Pest Management in WI Field Crops Bulletin A3646 for these options.

Image 1. Feekes 4-5 or Zadoks 30 growth stage in wheat

Chris Boerboom

A New Feature - Weather Updates from Winter Wheat Variety Trials

During the winter period, we were able to purchase four new weather stations for use at the winter wheat variety trial locations. To help provide information from those weather stations to growers, we will posting on a near-weekly basis graphs for temperature, relative humidity, and rainfall. We hope you find these useful.

PERIOD: 26 APRIL TO 2 MAY 2009


Location: Arlington



Location: Chilton



Location: Janesville



Location: Lancaster

Small Grain Aphids Have Arrived, but at Extremely Low Numbers

I scouted our winter wheat planting date by barley yellow dwarf virus trial this morning at Lancaster WI. Our earliest planting date (September 17th 2008) survived the winter very well and is nearing the Zadoks 30 (pseudostem erection) growth stage. Crop development of the later planting dates (September 30th and October 13th) are significantly behind the earliest date, Zadoks 13, 22 and 12, respectively. Across all of our plots I found only one Oat Bird Cherry aphid. The established spring threshold for this pest is 50 aphids per linear foot of row.

Oat Bird Cherry Aphid

Drawing Courtesey of Dennis Murphy

Wheat Fusarium Head Blight Prediction Center - 2009

The Wheat Fusarium Head Blight Prediction Center and forecast tool is now active for 2009. The site can be accessed at http://www.wheatscab.psu.edu/. I will again be writing state commentary for this site and will update growers on wheat growth stages in relation to our observations of wheat diseases. We will have an active wheat program for 2009, with our disease assessments commencing at Zadoks 30 (Feekes 4-5, or jointing) and continuing through our head blight assessments at approximately soft dough. We recently wrote for the Wisconsin Crop Manager an updated article on making foliar fungicide decisions based on current knowledge of disease thresholds for diseases like rust, powdery mildew, and Septoria leaf blotch. That is available here.

WSMB Offers Free Soybean Cyst Nematode Testing

Shawn Conley, Paul Esker, and John Gaska

The UW-Madison Agronomy Department, in cooperation with the Wisconsin Soybean Marketing Board, is again offering free soybean cyst nematode (SCN) soil testing for Wisconsin growers. This program is intended for growers to sample several of their fields in order to identify if SCN is present and at what levels. Growers will be responsible for collecting soil from fields suspected to have SCN and then sending the sample to the SCN testing laboratory for analysis. They will receive a lab report back with the SCN egg count and a brochure to help plan future rotations and other cultural practices to lower SCN infestation if they exist.

We have a limited number of these free kits available and will furnish them on a first come - first served basis at up to four per farm. Crop consultants, advisors, and crop input retailers are encouraged to request kits for their client’s farms. Each kit has a bag and a prepaid mailer for one soil sample, which should represent about 10-15 acres. Both the postage and lab fees are prepaid. Anytime before, during, or right after the growing season are great times to collect soil samples for routine soil fertility analysis and for SCN monitoring.

Soil sample test kits are available now and can be requested from Colleen Smith at clsmith8@wisc.edu or at 608-262-7702.

For more information on SCN testing and management practices to help reduce the losses from this pest, please contact: Shawn Conley: spconley@wisc.edu; 608-262-7975

Summary - 2009 Winter Wheat Workshops

The first ever Winter Wheat Workshops were recently completed in Wisconsin. We wanted to take this opportunity to thank all of the participants who attended the workshops. We also want to thank our industry sponsors (Partners in Production and Syngenta), as well as Jim Stute (UW-Extension Rock County), Mike Rankin (UW-Extension Fond du Lac County), and Mike Ballweg (UW-Extension Sheboygan County) for being host sites. Based on feedback from participants, we do plan to offer workshops again in 2010 and we will keep you posted on dates and times at a later date. Also, based on requests from participants, we are making available here copies of the slides from the talks (posted in PDF format).

Understanding Wheat Growth and Development and Wheat N Management Decisions

Disease Diagnostics and Foliar Fungicides

Should You or Shouldn't You - Bin Run Seed?

Insect Diagnostics

For further information regarding agronomic, entomological, or plant pathological information pertaining to wheat, please consult our respective websites:

"CoolBean.Info": http://coolbean.info

"Field Crop Pathology": http://www.uwex.edu/ces/croppathology

"Field and Forage Crop Entomology": http://www.entomology.wisc.edu/cullenlab

A Snap Shot of Argentina Agriculture

Shawn Conley and Paul Esker

Paul and I had the opportunity to spend the last week in the Pampas region of Argentina with fellow scientists Seth Naeve (Minnesota), Palle Pedersen and Jason DeBruin (Iowa), and Chad Lee and Jason Sarver (Kentucky). During this time we had an opportunity to meet with several growers, agricultural agencies, ag service organizations, seed companies, farm managers, and university researchers. The following article is not meant to be a thorough analysis of Argentinean agriculture, but a compilation of our observations.

(Image from Paul Esker)

In some ways Argentina is not that different from production in the Midwest. The cost to purchase or rent highly productive land is similar to what is paid in the U.S. Many of the growers we spoke with emphasized the use of rotations, sustainability, and managing the land for their children’s children. They also spoke of low profit margins and stability of their market given high input prices and dropping commodity prices.

It was described to us by many that the typical Argentinean producer owns ~20% of the land they operate and leases 80%. Most growers do not live on the land that they operate. They live in the city and own very little equipment, therefore, grower’s contract out almost all of their operations (planting, spraying, harvest, etc.). It was interesting to note that two separate individuals asked if U.S. farmers really live on their land like in the movies.

Argentinean growers are very proud of their movement into no-till production systems and know what year they made the transition for every farm they run.

(Image from Seth Naeve)

Given their latitude (approximately from about Indianapolis to Mexico City as a frame of reference) crops are relatively insensitive to planting date. They manage their rotations, plantings of soybean maturity groups, and corn hybrids around annual rainfall patterns. The three most common rotations we experienced were corn, full season soybean, and wheat double crop soybean. Most growers we spoke with would like to be on a 1/3, 1/3, 1/3 rotation. They feel this provides them with a stable rotation that maximizes productivity and hedges against risk. However given the estimated return per acre for corn it is little wonder why we saw the number of soybean acres planted as we did.

The most common estimate for new soybean seed planted annually was ~20%. The remaining acreage of RR soybeans planted is bin-run. The reason most cited for relying on bin-run seed is the “retentions” that growers pay on soybean. To our understanding this is a flat fee of 35% on all soybeans sold. To our understanding, these “retentions” support social programs in Argentina. Additionally, growers also pay sales taxes.


For the regions we visited the full season soybean was a late 3 maturity group whereas the double crop was an early to mid 4. Corn was typically a 110 to 120d relative maturity. To the best of our knowledge, wheat production is a hard red spring wheat with a growth habit similar to that of winter wheat.

(Image from Chad Lee)

It was quite interesting to note that all of the growers we spoke with do not see U.S. farmers as a competitor per se, rather they indicated that they strive to emulate U.S. production systems. Based on all of our conversations, the number one question that we received had to do with what U.S. growers were going to do next year: hold soybean acres or plant more corn.

Overall, we would strongly encourage any grower to take the opportunity to visit Argentina for themselves. We guarantee that the trip will be worth it.

Lastly, we very much would like to thank our host, Lucas Borras, plant physiologist with the University of Rosario for his tireless efforts in developing this program, serving as interpreter and host.