Northern Illinois Agronomy Research Center

Department of Crop Sciences---University of Illinois

COLLEGE of AGRICULTURAL, CONSUMER AND ENVIRONMENTAL SCIENCES

SEPTEMBER 2002 Newsletter Issue 19:5 Lyle Paul - Agronomist David Lindgren - Farm Foreman 14509 University Rd. Shabbona, Il 60550 Phone/Fax 815/824-2029 e-mail lylepaul@illinois.edu

/research/rdc/dekalb

2002 Weather Data:

2002 Precipitation (Inches)

2002 Growing Degree Days (Base 50)

Harvest:
Harvest has started in northern Illinois. An early corn harvest report from an area that was affected severely by drought was a yield of about 50 bushels/acre.

The soybean breeding crew from Urbana was going to harvest some of the soybean plots in the breeding research area on September 18, but the roughly 1/3" of rainfall received the previous overnight made them change their plans. As of the 24th, they were able to make a trip up and were harvesting 10-11% moisture soybeans. The yield levels are not very high with 50 bushels per acre or less catching most of the plots in the field. However, there were a couple of plots with yields of about 65 bushels per acre.

Soybeans Aphids:
Soybean aphid numbers this summer at the Research Center never reached the levels for good research work. There was an area in Stephenson County where the Entomology group was able to an aphid control study. We have not heard the results of that study at this point.

Corn Rootworm Insecticide Efficacy Trials:
The preliminary root rating results from all of the rootworm insecticide efficacy trials were published in the September 6 edition of the Pest Management & Crop Development Bulletin. The trail at the NIARC again has the dubious distinction of having the worst roots and the poorest control of the three sites which also included Monmouth and Urbana. On the Iowa State root rating scale of 1-6 with a rating of 1 given to plants with roots having no visible injury symptoms and 6 given to plants with 3 or more nodes of roots destroyed, the untreated checks at NIARC were 4.65. They could probably had a higher score, but to get a rating of 6, the plants needed three nodes of roots in the first place that could be destroyed. Some of the plants were falling over and dying at the time of the root digging. The economic damage is considered a root rating of 3 to 4 depending on the hybrid and the conditions of the year

General observations were that at DeKalb with the severe growing conditions and high levels of rootworm pressure, the levels of control was not very good. The control with the liquid treatments, Regent and Capture, were "troublesome" as the root ratings with those products were about the same as those of the untreated checks. Complete results will be discussed in more detail at the meeting and information before the next growing season. A complete table and discussion of the preliminary results are at the website http://www.ag.uiuc.edu/cespubs/pest/. Be sure to retrieve the September 6 edition.

Wheat Seeding:
The "ideal" seeding date (also the fly-free date) for wheat in this area has past. This date for the Research Center is September 19-21. Since no soybeans were harvested at that point, the only way to seed wheat by that date is to plant after another crop such as oats, peas or seed corn. According to the Agronomy Handbook, "seeding within the first 10 days after that date will result in little yield reduction. During the next 10-20 days, yields decline at the rate of a bushel or so a day. The yield loss accelerates to as much as 2 bushels per day from 20-30 days after the fly-free day. At one month after the fly-free date, yield potential is probably 60-70% of normal."

With the extended warm weather last fall, the yield reductions due to delayed planting at all timings were less than would have been expected. With soybean harvest being after the "ideal date" last fall also, the starting date of the study was about 8-10 days after the fly-free date. The following chart shows the results. Even being 46 days after the "ideal date" , the yield reductions from the starting point were only 20 to 30%.

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