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.
The heat is really pushing the corn along. Some fields have developed a ragged uneven appearance, because plants that have suffered root pruning from grape colaspis and grubs are falling behind. Rootworm larvae activity is adding to the problem. Japanese beetles are pupating and starting to emerge.
Soybeans are starting to develop rapidly as well. Postemergence spraying has been the major activity in soybeans.
Wheat harvest has started to the south but is still probably a week away in the north. Potato leafhoppers are currently very active in alfalfa fields.
The main activity this past week focused on soybean postemergence herbicide application. Also, cultivation and herbicide application were occurring in some of the later-planted corn.
Rainfall early in the week of June 15 ranged from 0.2 to 2.0 inches throughout the region. Rainfall would be wel-come throughout the region, as some corn on the lighter soils has begun to show heat stress with this week's hot temperatures. Generally, from May 1 to June 22, most of the region is behind by 160 to 200 growing degree-days from the long-term average, according to the Illinois Agricultural Statistics Service's recent crop report.
To date, this season we have received few reports of insect problems, including European corn borers. We did re-ceive a report of possible frost injury on corn from last Friday evening's cool temperatures.
An entire week of dry weather has growers scrambling to plant full-season soybean, replant soybean previously drowned out, harvest wheat, and plant double-cropped soybean.
Wheat harvest is progressing at a rapid rate, with yields better than expected considering the level of scab infection present. Reports of yields averaging from 60 to 80-plus bushels per acre are common, with test weights ranging from 58 to 63 pounds per bushel. We have also received reports of some wheat being rejected at the elevator due to the presence of DON (vomi-toxin) as a result of scab infection.
Numerous reports are also coming in regarding alfalfa leaf spot diseases. Common leaf spot, Leptosphaerulina leaf spot, and Stemphylium leaf spot may all be part of the disease complex being seen. These diseases can become serious when weather conditions remain wet and warm for an extended period. An additional factor this year was the harvest delay and lodging of the first cutting. The lodging resulted in many long stems being left after first cutting, providing fungal inoculum to infect the second cutting. Unfortunately, there are no effective fungicide treatments for these leaf spot diseases. The most effective preventive measure is to harvest plants as close to the ground as possible to reduce inoculum levels.
Reports of potato leafhopper attacking alfalfa also have escalated in the past couple of days. Growers should monitor stands closely after the second cutting.
Also right on schedule, Japanese beetle adults have emerged in the area. We have received no reports of problems from adult feeding yet, but early-planted cornfields approaching pollination will need to be monitored for silk clipping.
No rainfall has been received in the region for at least 10 days in most areas, and it has been as much as 2 weeks since some areas have received any precipitation. On Tuesday, temperatures reached the mid-90s for the first time this summer, and later-planted corn has begun to demonstrate signs of crop response to the high temperatures.
Most of the corn is V6-V11, with some of the earliest-planted fields as far along as V15. Soybean growth stages range from the first trifoliate to the sixth trifoliate, with a good portion of fields having canopied within the last week.
Alfalfa regrowth in harvested fields looks very good, and only a few reports of treatments being made for potato leafhopper have been received. Some fields being grown for high-quality hay have been cut for the second time. Pasture condition has begun to deteriorate the past few weeks, and many graziers have made the comment that pasture growth has been less than expected this year.
Field activities consisted mainly of postemergence herbicide applications on soybeans, mowing, baling hay, some sidedressing of nitrogen on late-planted corn, and prepping combines for wheat harvest, which is expected to begin within the next week in the southern portions of the region.