Issue No. 15/July 2, 2004
Training Session to Focus on Managing Summer Insects
"Managing the Insects of Summer" will be presented the morning of Tuesday, July 13, at the Crops Training Center in Shabbona (DeKalb County). Cost is $25; reservations are due by July 6.
Corn Rootworms Are Causing Serious Damage in Some Areas
Reports of severe damage by corn rootworm larvae feeding on corn roots include fields where a rootworm-control product was used at planting time. A research trial on the relationship of planting time and product efficacy is being conducted. The two rating scales available for assessing rootworm larval damage are presented. The effect of adult rootworms on pollination is addressed, and insecticides for control of adults are listed.
More on Japanese Beetles
Reports of Japanese beetles are increasing, but severe infestations have not been widespread. We cannot stress enough the importance of scouting throughout the entire field when determining the presence of Japanese beetles in corn.
European Corn Borer in Northern Illinois
Isolated reports have been received about small corn borer infestations in Illinois. Once corn borers begin to tunnel in the cornstalk, rescue treatments are no longer viable.
Diligent Scouting for Soybean Aphids Keeps Us Apprised of Developments Throughout the Midwest
Last year's outbreak of soybean aphids has many on the watch for a repeat. Resist the temptation to apply an insecticide before it is warranted. Determine pest density by scouting thoroughly; if density is below the threshold, keep scouting to see whether numbers are increasing or decreasing. Only increasing numbers are threatening.
Wheat Scab and Testing for Mycotoxins
Details are provided on tolerance levels for the mycotoxin DON (vomitoxin) in grain along with contact information for two testing laboratories.
Disease Update for Field Crops in Illinois
Commentary is given on common rust, gray leaf spot, anthracnose leaf blight, and crazy top in corn and on Septoria brown spot and root rots in soybean.
Soybean Leaf Cupping
Why does soybean leaf cupping, which has been common for several years, occur? Several theories are detailed, but in truth each case may be somewhat unique.
Adequate soil moisture throughout the state points to the likelihood of successful corn pollination, with relatively high potential kernel number. Early pollination is good, but it would be preferable to have grain filling end in September rather than August. In many fields flowers on soybean have appeared several weeks earlier than usual, which happens rarely enough that it is difficult to predict the consequences.
Reports are provided this issue for southern and west-central Illinois.