Archive for category: Uncategorized

We have begun our early season wheat disease assessments at the winter wheat variety trials in Wisconsin. Our approach for disease assessments follows the recommendations we made in the March 26, 2009 Wisconsin Crop Manager article, entitled, “Do I Need to Spray a Foliar Fungicide in Wheat in 2009?” These assessments are also a part of the thesis research for Karen Lackermann, Plant Pathology, to improve the decision management system for controlling wheat diseases in Wisconsin.

At Janesville and Lancaster, wheat growth and development currently ranges from Feekes 4-5 (pseudostem erection; Zadoks 30) to Feekes 6 (1st detectable node; Zadoks 31). In our assessments at those two locations, we have found symptoms of the Septoria leaf blotch complex, leaf rust, and stripe rust. The level of disease is relatively low and specifically, we have only noted symptoms in the lower canopy and nothing on the newest emerged leaf. At this range of growth stages, we do not recommend the use of foliar fungicides for Septoria or the rust diseases. Scouting over the next two weeks, however, will help to determine if these diseases are increasing in the canopy. Furthermore, the use of the thresholds we outlined in our Wisconsin Crop Manager article can help determine the need for a foliar fungicide as we move into flag leaf emergence.    

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.

Chris Boerboom

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.

Drawing Courtesey of Dennis Murphy

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

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.