The corn crop in Illinois is off to a good start in many fields, and in most areas is in the V5 to V8 growth stages, just starting its rapid growth phase. On average, the crop under good conditions will add some 200 lb of dry matter per acre per day over the next 80 days or so. It will take up 3-4 lb per day of nitrogen before pollination, after which the N uptake rate will slow.…
Once again, Drs. Dave Voegtlin (retired entomologist, Illinois Natural History Survey) and Dave Hogg (Professor of Entomology, University of Wisconsin) conducted their annual spring survey of soybean aphids. From May 12-17, they looked for soybean aphids on the primary host — common buckthorn, Rhamnus cathartica. At some sampling locations, they also examined the glossy buckthorn, Frangula alnus. The overall assessment by these entomologists — there were fewer soybean aphids this spring as compared with the previous 2 years.…
Larry Bledsoe and his Purdue University entomology colleagues have a long tradition of being the first to report the annual hatch of western corn rootworm larvae. Larry indicated to me and some other entomologists that hatch began to occur on June 2 on one of the research farms near the Purdue University campus.
Provided below is a list (19 years) of western corn rootworm hatch dates (for central Illinois and central Indiana) taken from previous Pest Management and Crop Development Bulletin articles (since 1996) and based upon observations by Larry Bledsoe and other Purdue University entomologists.…
Reports of potato leafhoppers in alfalfa typically begin to increase in late May and early June. Many entomologists consider potato leafhoppers to be the most significant economic insect threat to profitable alfalfa production. Recently a team of entomologists from the University of Wisconsin, the Illinois Natural History Survey, and the USDA ARS authored a peer-reviewed pest profile of potato leafhoppers. This profile offers up-to-date information on the biology, life cycle, injury, hosts, and management options for this key pest in alfalfa.…
Integrated weed management programs offer the greatest potential for long-term, sustainable solutions to weed populations demonstrating resistance to herbicides from multiple families. Soil-residual herbicides are important components of integrated weed management programs and provide several benefits, including reducing the intensity of selection for resistance to foliar-applied herbicides. Recent survey data indicate the percentage of Illinois soybean acres treated with soil-residual herbicides has increased during the past few years.
In the vast majority of instances, soil-applied herbicides control target weed species with little to no adverse effect on the crop. …
There have been scattered reports of armyworm infestations in southern Illinois wheat with some fields receiving an insecticide treatment. I encourage producers to review the biology, life cycle, and management information in the University of Illinois fact sheet on armyworms. With respect to economic thresholds, there is some variation from state to state. Provided below are thresholds from four land grant universities for consideration. They share some common features. If an insecticide rescue treatment is warranted,…
Soybean planting is off to a mediocre start in Illinois, with 26% of the crop planted by May 11, and limited progress with the rain of this past week. Planting will resume in some places this week, but other areas remain wet and it will take some time for soils to dry out. In comparison with recent history this is not yet a serious delay, but as time passes the delay will become a bigger concern.…
Planting progress may have been slowed by the recent precipitation, but weed emergence continues despite wet field conditions. Be aware that Palmer amaranth has begun to emerge. We scouted our Palmer amaranth field location west of Kankakee on May 8 and observed emerged Palmer amaranth plants (Figure 1).
We returned to the field on May 15 to find a very robust Palmer amaranth population (Figure 2). The largest Palmer amaranth plants found on May 15 were approximately 2 inches tall with 6 to 8 true leaves.…
We invite you to attend the 2014 University of Illinois Weed Science Field Day on Wednesday, June 25th at the University of Illinois Crop Sciences Research and Education Center, located immediately south of the main campus. Coffee and refreshments will be available under the shade trees near the Seed House beginning at 8:00 a.m.
Similar to past years, we will car pool to the fields where participants can join in a guided (but informal) tour format. …
Wheat plants are now beginning to head out and flower in parts of southern Illinois. During this critical time of wheat development, wheat becomes susceptible to infection by Fusarium graminearum, the causal agent of Fusarium head blight (FHB; also known as scab) (Fig. 1). This disease can cause reduced grain yield, test weight, and quality. In addition, the fungus can produce toxins that will contaminate grain such as deoxynivalenol (DON; also known as vomitoxin).…