No. 04/April 19, 2002|
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|IN THIS ISSUE:|
|Captures of Black Cutworm Moths Increase Dramatically|
The weather front that brought significant rains into Illinois during the weekend of April 12-14 also brought in a horde of black cutworm adults. Many people reported dramatic increases in their captures of black cutworm males in pheromone traps.
Higher numbers of black cutworm moths captured in pheromone traps do not always result in subsequent heavy infestations of black cutworm larvae. However, the arrival of the moths in Illinois before much of the corn has been planted should place people on alert for potential problems when corn begins to emerge.
|Add Warrior to the List of Products for Cutworm Control|
Table 2 in last week's Bulletin, preventive insecticides registered for control of black cutworms in corn, should have included Warrior. The oversight occurred because the language regarding cutworm control appears under "General Directions for Use" rather than in the spray recommendations for corn.
|Identifying Cutworm Larvae Accurately Will Become Important Soon|
Although most of the attention on cutworms focuses on the black cutworm, a few other species of cutworms also can be found in cornfields. It's important to be able to distinguish among the species you find so that accurate control decisions (including a decision not to apply an insecticide) can be made. This article includes information about the following cutworm species:
|Captures of a Few Armyworm Moths Deserve Attention|
The armyworm outbreak of 2001 is still a fairly vivid memory for some people, so captures of armyworm adults in traps this spring deserve some attention. We have always known that armyworm moths fly into Illinois at the same time that black cutworms arrive, but this time we should be more vigilant to watch for their arrival.
|EPA Has Approved the Use of Higher Rates of Fortress Insecticide|
The U.S. Environmental Protection Agency approved the use of higher rates of Fortress 2.5G and 5G insecticides for control of insect pests of corn.
|Alfalfa Weevils Are Active Throughout Southern and Central Illinois|
Although we have received little information about alfalfa weevil activity in southern Illinois, entomologists in Indiana, Kentucky, and Missouri are reporting that some fields in their states are heavily infested.
Based on degree-day projections, alfalfa weevils will be active in northern Illinois by the end of the month. Alfalfa growers in parts of southern Illinois will be well on their way to getting through "alfalfa weevil season." Keep in mind that the record warm temperatures we have experienced will accelerate alfalfa weevil development.
|Recognizing Corn Nematode Problems|
This article includes a description of corn nematode damage and suggestions for control.
|Be Aware of Aphanomyces Root Rot of Alfalfa Caused by Different Races of Aphanomyces in Illinois|
Aphanomyces root rot of alfalfa can be severe, and alfalfa growers should be aware of it. We have no reason to suspect it is a new disease of alfalfa, but it is likely that it has been one of the diseases causing serious damage to seedlings, as well as reduced yields in established stands, for many years.
This article includes a description of its symptoms and information about control.
Soil-applied herbicides remain an important part of weed control programs in corn and, to a lesser extent, soybean production systems. This article describes the factors that influence the effectiveness of soil-applied herbicides, regardless of when or how a herbicide is applied to the soil.
|Thinking About Planting Conditions|
It takes only about 2 days of temperatures in the 80s to get people planting. Without doubt, only 2 days of high temperatures do a lot to bring soil temperatures up. And along with this temperature increase comes a large increase in the rate of drying. That's especially true when the wind blows. Surface soil moisture has dropped rapidly.
In general, we should be making a seedbed that leaves the planter to do what it was designed to do--break clods next to the seed furrow, firm the soil around the seed such that seed-soil contact is good, and to place seed at uniform depth. Modern planters have been engineered to do this. We need to do any tillage with this in mind: leave something for the planter to do. Otherwise, we can easily end up with seed in less than ideal conditions to foster rapid emergence.
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.
This week's issue includes reports from northern, southern, and west-central Illinois.