Issue No. 19, Article 5/August 13, 2010
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 majority of the northern region has received 1 to 1.5 inches of rain or more since August 3, with a report of 3.8 inches at the Northern Illinois Agronomy Research Center near DeKalb. According to the Illinois State Water Survey WARM database, from April 20 to August 10, 2,104 growing degree days have accumulated at Freeport and 2,020 at DeKalb. Accumulated GDDs are above the 11-year average by 236 at Freeport and 136 at DeKalb. The recent hot and humid conditions are not ideal for the crops, but soil moisture has been adequate in most areas.
A few observations of sudden death syndrome and white mold in soybeans have been reported, but the conditions are not widespread at this time. Some producers continue to treat for potato leafhoppers in alfalfa.
Continued high nighttime temperatures and lack of rainfall are beginning to take their toll on potential corn yield, with kernel abortion at the ear tips being the most obvious symptom. Even so, the crop appears to be holding up well throughout most of the region. Given relatively early planting dates and high temperatures throughout most of the summer, harvest will begin much sooner than we've experienced the past two years.
Soybean development, other than double-crop fields, is at R5 (pod fill), and flowering is nearly complete. Few foliar diseases are apparent so far, though some SDS can be found along the northern edge of the region. Spider mite damage can be observed along field edges in drier areas, especially where waterways and roadside grasses have been mowed.
Growers are beginning to ask about seed wheat availability and quality, indicating a renewed interest in the crop for this fall.
Rainfall up to 3 inches caused some localized flooding the evening of August 10, but most areas received little or no rain. High winds associated with the storm caused some minor lodging of corn. April-planted corn has dented and the milk line is 1/3 to 1/2 down the kernel. With temperatures forecasted to remain above normal, black line won't be too far into the future. Diplodia ear rot can be seen to varying degrees in some fields. Many fields also have quite a few ear tips nosed back. Apparently the lack of a good root system coupled with the hot temperatures, disease pressure, and cloudy days have caused a little higher level of kernel abortion.
Soybean development ranges from vegetative to R5. SDS has been seen in some April- and May-planted fields. Other diseases present include frogeye leaf spot, septoria, and bacterial diseases.