October 1, 2007
The high wheat
prices are causing some to consider trying winter wheat for the first time. Ive
found that most growers who make winter wheat a profitable crop are good at marketing the
straw. Maybe this isnt as critical with todays 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
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 whats 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. Ive 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
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,
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 (
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.
If you have any questions, please feel free to contact the Iowa State University Extension Office.
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