No. 14/June 26, 2003|
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|IN THIS ISSUE:|
|Japanese Beetles Are Here!|
Reports of the emergence of Japanese beetle adults are coming in. As they emerge, they will begin seeking host plants to feed on, including corn and soybeans. Economic damage may be caused by silk clipping in corn and defoliation in soybeans.
|Just a Reminder|
Keep scouting for European corn borers. Once larvae begin boring into midribs of leaves and stalks, rescue treatments are no longer an option.
|Planting Date and Bt Economics for European Corn Borer|
A recently published paper proves clearly that planting date can significantly influence return on investment of a Bt hybrid purchased for European corn borer protection.
|Corn Rootworm Pupa and Prepupae Detected in Central Illinois Cornfield|
The finding of a pupa and prepupae in a Champaign County cornfield suggests that first sightings of adult western corn rootworms could begin very soon, earlier than is typical. Let us know when you see adult corn rootworms emerging in your area of Illinois.
|Reduced Soil Insecticide Rates for Corn Rootworms: An Old Story Revisited|
In considering control tactics for corn rootworm, note the research on the efficacy (regarding prevention of larval injury) of reduced rates of granular soil insecticides.
|Can We Relax Yet?|
The corn crop is off to a good start in most areas, though concerns remain about water supply. Soybean growth has finally taken off; the most critical stage for moisture supply is late July and early August, as pods start to fill. Most wheat growers are finding yields coming in higher than expected, though quality concerns from Fusarium scab continue.
|Potassium Deficiency in Corn|
Symptoms characteristic of potassium deficiency in corn are being reported in central and northern Illinois, especially in the western areas. Poor root system, low soil potassium, tillage, and oxygen availability can all be factors in the problem. It is too late to correct the problem this year; fields that have not been soil tested for several years should be tested this fall.
Reports are provided this issue for east-central, northern, southern, and west-central Illinois.