October 1, 2007

 

WINTER WHEAT

 

The high wheat prices are causing some to consider trying winter wheat for the first time. I’ve found that most growers who make winter wheat a profitable crop are good at marketing the straw. Maybe this isn’t as critical with today’s prices.  For maximum yields the wheat should be seeded by October 1, although mid-October seedings can be successful. Make sure you can market the wheat. Soft red winter wheat is more suitable for eastern Iowa and easier to market. Select a variety with good winter hardiness and disease resistance. The wheat variety trial results for 2007 for Crawfordsville, Nashua, and Ames is at http://www.croptesting.iastate.edu/smallgrains/data/data.html. Yields averaged 60 bu/A this past year in the trials, but averaged 95 bu/A in 2006, one of the best ever for wheat. Wheat seed is in short supply this fall because of the increase in interest. Phosphorus is important for a good wheat crop and applications of 50 pounds/acre of nitrogen in March are typical. Fungicides are occasionally needed for maximum yields. Check herbicide labels for crop rotation restrictions, especially if seeding on corn ground. For more information, see Lance Gibson’s article at http://www.agron.iastate.edu/faculty/lgibson/Wheat.htm.

FALL STALK NITRATE TEST FOR CORN

A useful tool to help fine tune nitrogen management in corn is to use the fall stalk nitrate test. The ideal time to take the stalk samples is 1-3 weeks after black layer. Many corn fields may be beyond this window now, but later work done by Fred Blackmer indicated that sample can be taken later as well with similar results. An easy way to take the samples is right after harvest. An 8-inch segment of stalk with the leaf sheaths removed needs to be taken 6 inches above the soil. If the head is set to cut the stalks about 14 inches above the ground, the upper 8 inches of what’s left in the field can be cut off to be sent to the lab. It is recommended to send 15 stalk samples for each area being sampled. I’ve found the test to be especially useful on manured fields to identify where excess nitrogen was used or to make sure there was sufficient N. In areas where there were excess rain and nitrogen losses, the test can confirm the lack of N. Instructions for the test can be found at http://www.extension.iastate.edu/Publications/PM1584.pdf. If you choose to use the ISU lab, the form can be found at http://www.agron.iastate.edu/soiltesting/CSN.pdf.

 

Corn Fungicides and Yield

 

Iowa State University has corn fungicide trials at several locations in Iowa in 2007, but we are looking for additional information to supplement our data.  If you (or your customer(s)) applied fungicides to corn, left an untreated check strip, and have yield mapping capability, you can help by providing a yield map of the field, indicating where the fungicide was and was not applied, and completing a brief form and then sending the form with the map to me.  No data will be used in a manner where the individual producer can be identified.  The form can be downloaded from http://www.extension.iastate.edu/Pages/eccrops/07cornfungicideform.rtf.  The form is actually for replicated trials, so if you have only one treated and one untreated part of the field, just put that information in the area for rep 1 and leave the other reps blank.  You can send the maps and forms to me electronically at vschmitt@iastate.edu or through the United States Postal Service and I’ll pass them on.

 

 

Scattered Dark Kernels on an Ear of Corn

 

I have received a few inquiries regarding scattered dark kernels on ears of corn.  At first glace, it looks like a mold (fusarium); the pattern on the ear is correct for fusarium but fusarium is lighter in color.  The observed dark kernels are genetic and occur when some hybrids receive pollen from another hybrid that has Reid Iodent somewhere in its parentage.  In 2004, A. Forrest Troyer, University of Illinois, reported, “Reid Yellow Dent is 51% of the documented U.S. hybrid corn background (Iodent Reid, 13%; …).”  See http://crop.scijournals.org/cgi/content/full/44/2/370.

To see a picture of fusarium, go to http://www.ent.iastate.edu/imagegal/plantpath/corn/fusarium/0796.105and108.html.

 

To see a picture of the Reid Iodent cross pollination phenomenon, go to http://www.pioneer.co.nz/maize_management/pollination_to_maturity_ears_or_kernels_malformed.htm, which is a Pioneer (New Zealand) site.  Look at “Smokey Kernels.”  These are a little darker than what I’ve seen, but it’s the same thing.  The dark color does not indicate any lessening of quality of the grain.

 

 

CORN AND SOYBEAN YIELD TRIAL DATA

 

The 2007 Iowa State University Corn and Soybean Yield Trial data is beginning to show up at http://www.croptesting.iastate.edu/.  As the raw data is accumulated at each location, it is being posted at this web site in spreadsheet format.  Once harvest is complete, the data will be consolidated and analyzed and those results will also be posted at this web site.