Issue No. 21, Article 8/August 14, 2009
Extension center educators, unit educators, and unit assistants in northern, west-central, east-central, and southern Illinois prepare regional reports to provide more localized insight into pest situations and crop conditions in Illinois. The reports will keep you up to date on situations in field and forage crops as they develop throughout the season. The regions have been defined broadly to include the agricultural statistics districts as designated by the Illinois Agricultural Statistics Service, with slight modifications:
- North (Northwest and Northeast districts, plus Stark and Marshall counties)
- West-central (West and West Southwest districts, and Peoria, Woodford, Tazewell, Mason, Menard, and Logan counties from the Central district)
- East-central (East and East Southeast districts [except Marion, Clay, Richland, and Lawrence counties], McLean, DeWitt, and Macon counties from the Central district)
- South (Southwest and Southeast districts, and Marion, Clay, Richland, and Lawrence counties from the East Southeast district)
We hope these reports will provide additional benefits for staying current as the season progresses.
A large portion of the region received 1 to 2 inches of precipitation last week. Western bean cutworm moth trap catches have declined this week compared to the previous two. There has been some fungicide application on corn the last several weeks, but it appears that fewer acres are being treated than last year. According to the Illinois State Water Survey WARM database, at Freeport and DeKalb from May 10 to August 11 accumulated corn growing degree-days are more than 200 below the 11-year average.
Jim Morrison, crop systems extension educator, reported that a soybean field at R4 (full pod) in Jo Daviess County averaged 20 soybean aphids per plant and a Boone County soybean field at V8 averaged 30 aphids per plant. However, no winged aphids were observed.
Corn pollination is all but over, with the exception of a field or two of late planted/replanted corn. The most mature corn is dent stage. There are very few concerns with pollination, with the exception of wet areas of fields where maturity has been delayed. Those who have taken advantage of air flights to review corn stands report erratic growth and development, which one would expect considering the wet season.
Soybeans range in maturity from late vegetative to R5, depending on plant date. Some symptoms of SDS can be seen on a few fields of early-planted soybean. Some low-level soybean aphid populations exist as well. Loretta Ortiz Ribbing found some white mold at the WIU research center this week.