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.
Japanese beetles are still numerous and showing up in places they haven't been seen before. There have been some reports of significant silk clipping, but pollination is pretty much complete. Several reports of corn leaf aphids have been received, but again, pollination is almost over. Small numbers of spider mites and soybean aphids can be found almost anywhere.
Western corn rootworm activity in soybean fields really started this week. Traps put out last week in a field in Macon County yielded just under five beetles per trap per day.
The main concern across northern Illinois is the dry condition and its effect on corn pollination. Since late June, some areas have received less than l/2 inch of rain, while other areas have received more than 3 inches. If rain is not received within the next week, pollination on the lighter soils definitely will be affected. To date, corn on higher organic matter soils have not exhibited consistent moisture stress.
Stan Eden, Ogle County Extension educator, reported high numbers of corn leaf aphids interfering with corn pollination in some sandy fields. Dave Feltes, IPM Extension educator, reported economic populations of potato leafhoppers in alfalfa fields throughout northwest Illinois. If the dry conditions persist, producers are encouraged to scout soybeans and monitor spider mite populations. Dave Feltes reported that insecticide treatment for spider mites has occurred in Iowa, across the river from Whiteside and Carroll counties.
Numerous instances of cupped, puckered soybeans due to postemergence herbicide applications have been reported and observed.
A number of things have not changed in the past week. The weather is hot and soil moisture is variable across the region. Most of southern Illinois is abnormally dry; however, there are locations with adequate plus topsoil moisture.
Crop condition is as variable as soil moisture. Corn is R2R4. Regular crop beans are setting pods and double crops are V3-V4. Crops that are not under moisture stress look very good.
Disease and insect problems have been minimal. There has been one unconfirmed report of soybean SDS. Prairie vole populations have remained high and have damaged double-cropped beans. Southwestern corn borer flights continue to be monitored. Ron Hines, DSAC, reports that SWCB moth numbers appear to be greater in irrigated or moist locations.
The Brownstown Agronomy Field Day is July 26, 2001, starting at 3:00 p.m. Two tours are available.
Much-needed rain fell in most areas of the region Tuesday night and Wednesday morning. Amounts in excess of an inch were commonly reported.
Before the rain, some cornfields were showing signs of moisture stress, especially the latest-planted fields. Yellowing of lower leaves because of nutrient deficiencies or drought was also apparent in some fields. Several fields have been treated for aphids. Western corn rootworm larvae and beetles can be found in the northern part of the region.
Spider mite damage started to appear in some soybean fields, and some of those fields were treated with an insecticide. No other pest problems have been reported in soybean.
Potato leafhopper is a major problem in alfalfa. One observer stated, "They are the worst they have been in years. All alfalfa fields have been or will be sprayed."