The Bulletin Archives - Page 68 of 78

Do Soybeans Need N Fertilizer?

April 16, 2014
Emerson Nafziger

There has been a great deal of interest in recent months in the idea of using nitrogen fertilizer during the growing season to increase soybean yields. This is somewhat surprising given that there has been so little evidence from published and unpublished reports showing that this practice increases yields, let alone provides a return on the cost of doing this.
Soybean plants in virtually every Illinois field produce nodules when roots are infected by Bradyrhizobium bacteria,…

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Terminating cover crops

April 16, 2014
Aaron Hager

The number of acres in Illinois seeded with various cover crops has increased during the past few seasons. Those cover crops that do not winter kill are usually controlled the following spring with herbicides. Dr. Bob Hartzler, extension weed scientist at Iowa State University, recently published an excellent article in which he describes several factors that can impact the performance of spring-applied herbicides used to terminate cover crops. We sincerely appreciate Dr. Hartzler’s willingness to allow us to reproduce his article which follows.…

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Field Evolved Western Corn Rootworm Resistance to Bt (Cry3Bb1) Confirmed in Three Additional Illinois Counties

April 3, 2014
Michael Gray

On August 24, 2012, in cooperation with Dr. Aaron Gassmann’s laboratory, Iowa State University, I confirmed the evolution of field resistance by western corn rootworms to the Cry3Bb1 protein in some problem fields located in northwestern Illinois (Henry and Whiteside Counties). During the summer of 2012, Dr. Joe Spencer, Illinois Natural History Survey, received suspected Bt-resistant western corn rootworm adults that had been collected in continuous cornfields in McDonough, Mercer, and Sangamon Counties. Eggs were obtained from these adults in the laboratory.…

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Management of Palmer amaranth in Illinois

March 27, 2014
Aaron Hager

Palmer amaranth is a weed species that must be thoughtfully and carefully managed; simply attempting to control Palmer amaranth often leads to ineffective herbicide applications, substantial crop yield loss, and increasing weed infestations. Ignored or otherwise not effectively managed, Palmer amaranth can reduce corn and soybean yield to near zero. The threat of Palmer amaranth during the 2014 growing season is very real across a large portion of Illinois.
In January 2014, the weed science program at the University of Illinois developed recommendations for management of Palmer amaranth in agronomic crops. …

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Webinar to Focus on Nitrogen

March 24, 2014
Emerson Nafziger

While dry weather is allowing N application to start in some places in Illinois, the ongoing cool temperatures continue to raise questions about N management this spring.
With help from the Council on Best Management Practices (C-BMP), we are organizing a webinar for Thursday, March 27 at 8:00 AM to address some of these issues, including fate of fall-applied N, use of inhibitors this spring, and how cool soils might affect soil N supply and plant uptake.…

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Cover Crop Field Day March 28th at the Ewing Demonstration Center

March 18, 2014
Nathan Johanning

Hearing a lot about cover crops lately but unsure if or how they will work for you? Then plan to attend the Cover Crop Field Day at the University of Illinois Extension Ewing Demonstration Center on March 28, 2014 starting at 10 AM. The field day offers the latest information on cover crops uses – from livestock grazing, soil erosion and compaction reduction, increasing soil organic matter, to increasing future nutrient availability.
Topics for the tour include:
– …

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Western Corn Rootworm Egg Survival and the Winter of 2013-14: What’s the Likely Outcome?

March 18, 2014
Michael Gray

The winter of 2013-14 will long be remembered as one of the snowiest and coldest since the late 1970s for many midwestern states. Not surprisingly, many questions have surfaced regarding the impact of these cold temperatures on the overwintering survival of western corn rootworm eggs. Research on this topic has only sparingly occurred. In my estimation, one of the best field studies on this challenging research area, was undertaken by an Iowa State University graduate student,…

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Soil Temperatures and Spring Prospects

March 18, 2014
Emerson Nafziger

We hope that we’ve seen the last of the snow by now, but both air and soil temperatures remain below average in Illinois heading into the second half of March. According to the Illinois State Water Survey (http://www.isws.illinois.edu/warm/soiltemp.asp) minimum temperatures 4 inches deep under bare soil ranged from the low 30s in northern Illinois to the mid-30s in southern Illinois the morning of March 17, and with some sunshine on that day, reached the upper 40s to low 50w in southern Illinois but did not get above the low 30s in the northern part of the state.…

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Western Corn Rootworm Management Webinar (February 20, 2014) Recorded and Available for Viewing

February 26, 2014
Michael Gray

On February 20, 2014, a webinar was presented by five land grant entomologists (see below) concerning western corn rootworm management challenges and recommendations. As we move forward this year, there remain many lingering concerns regarding the root protection performance of some Bt hybrids in light of the evolving resistance to certain traits. The live webinar was well received (over 300 participants); however, for those unable to take part in this session, you can now view the recorded session. …

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Corn Rootworm Management Webinar – February 20, 2014

February 3, 2014
Michael Gray

As we approach the 2014 growing season, many questions remain concerning how best to manage western corn rootworms in light of the on-going concerns over resistance to some Bt proteins. A corn rootworm management webinar will be available on February 20 (Thursday), 2014. The program will begin at 1 PM (CST) and conclude at 3:30 PM. The program is supported by a USDA-NIFA North Central IPM Program grant. An excellent slate of land grant entomologists will take part in this session:

Rootworm biology and behavior;

…

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