Issue No. 18/July 27, 2007
Soybean Aphids at Economic Levels in Some Illinois Soybean Fields
Some northern Illinois soybean fields are now harboring levels of soybean aphids near the economic threshold. Fields throughout Illinois should be scouted soon and frequently.
Correction Made to Degree-Day Calculator for Western Bean Cutworms
The biofix date for begin accumulating degree-days for western bean cutworm should be May 1.
Remain Vigilant for Herbicide-Resistant Weeds
Reports of poor control of waterhemp with glyphosate and PPO inhibitors are now frequent in Illinois, and similar reports are being received about giant ragweed and common lambsquarters.
Similar Symptoms on Soybean: Phyllosticta Leaf Spot Vs. Frogeye Leaf Spot
It is important to distinguish, using magnification, between the similar symptoms of Phyllosticta leaf spot and frogeye leaf spot fungal diseases.
Soybean Rust Recently Found in Arkansas
The expansion of states in which soybean rust has been found in 2007 amplifies the importance of scouting fields in Illinois.
Are Corn and Soybean Crops As Good As They Look?
Recent reports of second corn ears arising from main ears, of new silks emerging among brown silks, and of lower stalk weakness make it advisable to get into corn fields for a closer look. In soybeans, the rapid development of the canopy once rain arrived may affect podding.
Reports are provided this issue for northern and southern Illinois.