Hill and Furrow Current topics about crop production in Western Illinois, including field crops research at the NWIARDC in Monmouth. Sun, 15 May 2005 13:02:08 -0500 http://web.extension.illinois.edu/nwiardc/eb270/rss.xml Scouting shouldn't end until after harvest http://web.extension.illinois.edu/nwiardc/eb270/entry_12682/ Wed, 30 Aug 2017 14:43:00 +0000 http://web.extension.illinois.edu/nwiardc/eb270/entry_12682/ Scouting is a season-long commitment, beginning before planting (measuring soil temperature and assessing condition), continues after planting (assessing plant stands and then scouting for disease, insect and weed pressure) only ending after the crop has been harvested.

Late season scouting of corn can include monitoring kernels for maturity (black layer) and moisture content and checking plants for ear molds and stalk strength.

Checking stalk strength.

Stalk rots can reduce yields. Stalk rots can decrease harvestable yield - literally leaving some ears on the ground. Corn plants are top-heavy and stalk rots increase the chance that plants will fall over (lodge) due to a combination of gravity and weather.

Conditions that favor stalk rots. Mid-season environmental conditions that favor kernel-set followed by conditions that favor plant stress increase the risk of stalk rot disease. Kernels place a very high demand on the plant for sugars. Stress reduces the rate of photosynthesis, thereby reducing the amount of sugars that the plant is able to produce. If unable to keep up with kernel sugar demand, the plant can rob sugars from other plant parts, including stalks. Many different stresses can reduce the rate of photosynthesis in the crop: too much or too little moisture; nutrient imbalances; leaf injury (ex.: hail, insects, diseases); high plant populations; and even long-periods of cloudy weather. Low stalk sugar content can increase susceptibility to stalk rot pathogens. Many of the fungi that cause common stalk rots in Illinois survive in corn residue and continuous corn and conservation tillage can increase the risk of stalk rot.

Scouting for lodging potential. Scouting for stalk rots is essential to minimize harvest losses. Begin scouting fields now or just before physiological maturity (black layer) when grain moisture is between 30 and 40 percent. Walk each field in a zigzag pattern, checking random plants from multiple areas of each field. To check a plant for stalk strength, either pinch it or push it. For the pinch test, pinch stalks toward the bottom, below the lowest node, checking for firmness. For the push test, at waist height push the plant 30 degrees from vertical to see if it returns to an upright position and the stalk remains intact (Figure). With either test, there is a significant lodging potential if 10 to 15 percent of the plants fail your particular test.

Harvesting first those fields with the greatest lodging potential reduces the chances of having to harvest lodged corn. Remember to drive slowly and harvest against the grain in lodged corn.

The next corn crop. Hybrids vary in their susceptibility to common stalk rots. Look into purchasing seed with good 'stalk rot', 'lodging', or 'standability' ratings.

Checking for ear molds.

While some of the fungi that cause ear molds can cause symptoms on husk leaves, not all do and so it is important to peel back these leaves and look at ears from multiple locations throughout each field.

Yield loss due to ear molds. Yield can be lost through smaller kernel size and lower test weights. This, along with moldy or damaged kernels, fine materials and mycotoxin contamination can result in discounts at the grain elevator.

Properly identifying ear molds is important. University plant pathologists recently produced a nice color documents that can help in identifying ear rot symptoms and offers information regarding risk of mycotoxin contamination and management recommendations.

Drying and Storing Moldy Grain. With on-farm storage, many crop producers have the option to hold onto their grain to market it at a later time. Storing diseased grain separately and for only short periods of time is recommended to reduce the chance of additional losses. Those ear molds associated with mycotoxin contamination can add additional complications to the drying and storage processes.

Agricultural engineers from Iowa State University have produced several tools that can help those interested in learning more about just how long air drying may take with a given fan and grain bin size and the crop moisture and air temperatures outside. For those that have the ability to add heat to the drying process, these experts have also produced tools that can help in factoring all of the costs associated with drying with or without heat.

Here are resources related to these topics produced by Iowa State University Agricultural Economists and Engineers:

Grain Storage - Quality Management​:
Dryeration
Aeration
Fan Performance

Grain Storage – Economics:
Grain Drying Economics
Grain Storage Economics

Palmer at harvest. While one would hope to have an idea about whether a field is infested with Palmer amaranth, some producers may be taken by surprise at harvest time. It is important to make preparations for encountering Palmer during harvest to avoid spreading seed of this aggressive weed species throughout the field.

Here are some suggestions.

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Making informed foliar fungicide decisions = scout before tasseling time http://web.extension.illinois.edu/nwiardc/eb270/entry_12670/ Thu, 06 Jul 2017 08:00:00 +0000 http://web.extension.illinois.edu/nwiardc/eb270/entry_12670/ Foliar fungicides in corn - a historical perspective. From the early 1970's through the mid-2000's, when prices averaged close to $2 per bushel and corn was considered a lower value crop, producers worked to minimize all but the most essential inputs. Between 2010 and 2012, when corn prices reached historic highs, producers may have considered additional inputs. While many production costs remain high, corn prices have since fallen and are projected to average below $3.75 per bushel for the 2017 crop marketing year. All input decisions become more urgent during these leaner years – to be profitable, each input must increase yield enough to at least pay for itself.

Foliar fungicides - making an informed decision. Making an informed decision about whether to apply a foliar fungicide can be difficult and involves gathering information about each aspect of the disease triangle: the pathogen, the plant and the environment. Most of the foliage-infecting fungi responsible for economic yield loss in Illinois corn are favored by wet and humid weather and survive in residue from previously-infected crops. Consequently, disease risk is higher when planting into a field with a lot of corn residue or a history of disease. On the plant side, seed companies typically provide a numeric rating of the level of genetic disease resistance in each hybrid and foliar fungicides are generally not recommended on resistant hybrids. In addition to monitoring weather conditions, scouting fields for disease provides valuable information about the fungal disease pressure in any given field.

Scouting for disease is an essential component to making an informed decision regarding a foliar fungicide.

A "profitable" fungicide application = breaking even. A profitable fungicide application is one that increases yield enough to at least pay for itself, and includes the costs of both fungicide active ingredient(s) and application. For those that need to hire this service out, the per-acre cost may range between approximately $31 and $46, and largely depends on whether fungicides are still under patent-protection. A break-even yield response, therefore, varies based upon both application costs and grain prices. In order to break-even under these fungicide and corn prices, a foliar fungicide would need to increase yield by more than 8 and up to 12 bushels per acre or more.

Between 2008 and 2014, in multiple locations throughout the state, former University of Illinois Extension Plant Pathologist Dr. Carl Bradley and his team conducted 45 different replicated corn foliar fungicide trials. The data collected in these 45 location-year environments can provide indications as to when foliar fungicides are most likely to be profitable.

In these experiments, fungicides were applied between VT and R1 growth stages and disease severity and yield data were collected from both fungicide-treated and un-treated control plots. In 28 of the environments, disease pressure was considered to be low, with less than 10 percent final disease severity in the untreated control plots. The remaining 17 environments had moderate to high disease pressure, with final disease severity 10 percent or higher on untreated plants.

Regardless of the yield response needed to break even with a foliar fungicide, the chance of doing so was higher in moderate to high disease pressure environments.

Fungicides in the absence of disease and pesticide resistance. While in some instances foliar fungicides can increase yield in the absence of disease, these physiological responses are both difficult to predict and inconsistent. Of additional concern, with each fungicide application, a selection pressure is exerted on pathogen populations. Those individuals that are insensitive to the fungicide can survive to reproduce, while those that are sensitive will die without producing offspring. This is how, over time and repeated cycles of selection, pathogen populations can shift from fungicide-sensitive to resistant. Reserving fungicides for those instances that are warranted from a disease management standpoint will serve to prolong their effectiveness.

Additional resources

Fungicide Efficacy for Control of Corn Diseases

Corn Foliar Diseases: Identification and Management Field Guide

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They're baaaack! Scouting tips and thresholds for Japanese beetles. http://web.extension.illinois.edu/nwiardc/eb270/entry_12667/ Mon, 26 Jun 2017 12:46:00 +0000 http://web.extension.illinois.edu/nwiardc/eb270/entry_12667/ When applying post emergence herbicides in several of the Northwestern Research Center's soybean fields over the last week or so, research specialist Marty Johnson noticed large clusters of Japanese beetles feeding on volunteer corn plants. When one beetle lands to feed it tends to attract a lot of friends and mates (Figures).

Japanese beetle ID. Japanese beetles are oval shaped and have an iridescent metallic sheen. They have a green head and thorax and copper colored outer wings with a green stripe down the center. There are also five white 'racing stripes' along each side of the beetle under the wings towards the posterior end, and two on the rear end. These are actually small white tufts of hair called setae (Figures). There are several Japanese beetle look-alikes, but the Japanese beetle can be distinguished by these white tufts of hair.

Japanese beetle behavior. Feeding damage on soybean and corn was also observed (Figures). This damage can be alarming, particularly if individual leaves are in tatters. Often-times the beetles tend congregate on field edges, and so damage occurs on the edge of the field. Scouting more than just the outside edge of the field should help to inform your decision on whether to consider an insecticide spray. Just sampling the outer edges of the field may over-estimate beetle density throughout the field.

Management recommendations: Soybean. Ms. Kelly Estes and Dr. Mike Gray of the University of Illinois have summarized information about the Japanese beetle on field crops in a fact sheet on the U of I's IPM website. For soybean, treatment recommendations depend upon the growth stage of the plants. Thresholds for treatment are 30% defoliation before bloom and 20% defoliation between bloom and pod-fill.

It may be difficult to train the eye to estimate defoliation, but a photo from Dr. Marlin Rice of Iowa State University, may help with visualizing the differences among the different levels of defoliation. One way to help train the eye is to imagine taking all of the holes in the leaf/leaflet and condensing them into one area. You can then more easily estimate how much is gone by relating this 'image' to the total leaf area. This is something that takes practice.

Corn. Corn recommendations are a little bit more cut and dried. Consider using an insecticide if during silking you have 1) three or more beetles per ear and 2) silks are clipped shorter than ½ inch and 3) pollination is less than 50% completed.

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Center Field Day - July 26, 8 AM http://web.extension.illinois.edu/nwiardc/eb270/entry_12573/ Fri, 23 Jun 2017 16:02:00 +0000 http://web.extension.illinois.edu/nwiardc/eb270/entry_12573/ Join personnel from the Northwestern Illinois Ag Research and Demonstration Center for their 36th annual field day on July 26.

Buses will leave the research center (321 201th Ave, Monmouth) at 8 AM sharp and travel to different stops where researchers will discuss their research at the center.

Presentation titles and presenters include:

  • Lessons from 35+ Years of Research at the Northwestern Illinois Ag Research Center, Emerson Nafziger—Extension Specialist, Crop Production—University of Illinois
  • Reducing Tile Drainage Nitrate Loss: Chippin' Away with Woodchip Bioreactors, Laura Christianson—Extension Specialist, Water Quality—University of Illinois
  • 2017: Insect Headlines in Western Illinois, Kelly Estes—Coordinator, Illinois Cooperative Agricultural Pest Survey Program—Illinois Natural History Survey
  • Important Soybean Diseases in Illinois, Roger Bowen—Visiting Research Scientist, Dept. of Crop Sciences—University of Illinois, USDA-ARS

Refreshments will be served and CCAs can earn up to 2 CEUs.

Additional questions should be directed to Research Agronomist Greg Steckel: gsteckel@illinois.edu, (309) 734-7459.

If you need a reasonable accommodation to participate in this program please contact Greg no later than 4 PM on July 5.

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Changes coming to Hill and Furrow http://web.extension.illinois.edu/nwiardc/eb270/entry_12666/ Wed, 21 Jun 2017 12:33:00 +0000 http://web.extension.illinois.edu/nwiardc/eb270/entry_12666/ Since the Hill and Furrow blog began in April 2012, a conscious effort has been made to keep its author (me) in the shadows so as to not distract from article content.

However as Friday, June 23 will be my last day at University of Illinois Extension, major changes will be coming to the Hill and Furrow.

I'd like to thank the blog's loyal subscribers and encourage you to not unsubscribe just yet, as there are a couple of more articles that have been scheduled to post throughout the 2017 growing season and my replacement is likely to start posting after he/she is hired.

Writing articles for this blog has been a labor of love and I will truly miss it, the Northwestern Illinois Ag R&D Center and the center's staff: Research Specialist Marty Johnson and Research Agronomist Greg Steckel.

Incidentally, the research center's 36th annual field day will be held on Wednesday, July 26 with buses leaving the center at 8 AM sharp. Click here for further information regarding the day's topics and speakers.

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Keep an eye out for bacterial leaf streak in corn http://web.extension.illinois.edu/nwiardc/eb270/entry_12663/ Tue, 20 Jun 2017 18:13:00 +0000 http://web.extension.illinois.edu/nwiardc/eb270/entry_12663/ Last growing season (2016) a new corn disease called bacterial leaf streak (BLS) was confirmed in Illinois for the first time in DeKalb County. Symptoms of BLS include narrow yellow, tan, brown or orange lesions with wavy margins that occur between and along leaf veins (Figure).

While symptoms of this disease were observed in Nebraska as early as 2014, it took scientists several years to identify the pathogen that caused the symptoms. In 2016 the disease was found in nine states and the cause of BLS was identified - a bacterial pathogen called Xanthomonas vasicola. Field-, seed-, pop- and sweetcorn are all susceptible to this bacterial pathogen.

As symptoms of BLS can be observed as early as the seventh leaf growth stage, now is the time to become familiar with how to identify this disease in the field. Proper identification is of particular importance as similar to other bacterial diseases like Stewart's wilt and Goss's wilt, foliar fungicides are ineffective. Foliar fungicides can provide protection against infection by fungal and not bacterial pathogens.

A nice digital fact sheet was produced by University plant pathologists detailing what is currently known about identification and management of BLS. It is available for viewing and for download at the Crop Protection Network website.

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Following Crop Development in a Corn Planting Date Trial http://web.extension.illinois.edu/nwiardc/eb270/entry_12569/ Thu, 18 May 2017 14:26:00 +0000 http://web.extension.illinois.edu/nwiardc/eb270/entry_12569/ You might have always wondered whether there was some way to estimate when your corn crop is likely to reach the silking and black layer growth stages. Well you might just be in luck if you gather the following information about a particular corn hybrid (when it was planted, where it was planted, its estimated days to maturity) and use any internet browser to visit Useful 2 Useable' s free corn degree day decision support tool.

I spent some quality time this morning scouting for cutworm injury in fields at the Northwestern IL Ag R&D Center. One field was planted to a 108 day hybrid in a corn planting date x fungicide trial. After counting leaf collars and taking a couple of pictures, I was able to plug in the location data (Monmouth) and days to maturity (108) into the decision support tool to estimate when silking and black layer growth stages are likely to occur (Figures and Table). I could also compare the beginning of 2017 to 2016 and years in which growth was a little bit more accelerated than normal (2012) and a little bit slower than normal (2013). This comparison showed that growing degree day accumulation for the April 11 planted corn is similar to 2012 (380) and ahead of both 2013 and 2016 (Figure).

Table. Planting dates and days after planting, accumulated growing degree days and growth stage on May 18 along with projected silking a maturity dates for corn in a planting date x fungicide trial at the Northwestern Illinois Ag R&D Center in Monmouth

On May 18

Projected ______ date

Planting Date

Days after planting

Accumulated GDD

Growth stage

Silking

Maturity

April 11

37

372

V4

July 9

Sept 3

April 24

24

227

V3

July 15

Sept 11

May 9

9

132

V1

July 19

Sept 17

As this decision support tool costs nothing but time it might be worthwhile to check it out on the next rainy day.

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