The 2018 small grains fungicide sheet is now available

We have published the 2018 small grain fungicide recommendation guide.  Please find a link to the guide and more information at the Illinois Field Crop Disease blog, which can be accessed by clicking here

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Positive Signs after a Slow Start to Corn Planting

Parts of Illinois received some precipitation for the third Sunday in a row (starting with Easter) on April 15, and in a few places, also for the third Sunday in a row, it came partly in the form of snow. That streak should end this weekend, and less rain and warmer temperatures are predicted to move in for the rest of April.

Some ammonia went on late last week and there was planting activity in places, but NASS reported no (meaning less than 1 percent) of the corn or soybean crop planted by April 15. It rained again over much of Illinois on April 13 to 15, and cool temperatures and slow drying of soils continue to delay the start of planting.

One concern when corn is planted into cool soils is the uptake of cold water as germination begins. When the first water moving into a dry seed is at a temperature below the mid-40s, “imbibitional chilling injury” (ICI) can result. Rain and lower air temperatures that followed planting in some fields on April 13 or 14, such injury is a possibility. We expect to see such damage more often than we actually see it, but low-moisture seed takes up (cold) water quickly, and moisture of planted seed planting might influence the amount of damage. If seed has a chance to take up warmer water before cold rain comes, such damage will probably no occur. Cold water makes membranes in the seed more brittle, and can cause cell death.

ICI damage usually shows up as abnormal seedling growth, often with “corkscrew” roots and shoots. The practical effect of this is that it lowers emergence. Unlike death of seeds from lack of oxygen, which was widespread following heavy rainfall after planting in 2017, ICI symptoms aren’t necessarily more common in low-lying parts of a field. There’s no fix for ICI – if it lowers stands enough, replanting may be necessary. But if affected seedlings are able to emerge, they may develop normally.

Almost every year in some part of Illinois, corn is planted into good soil conditions, but then it rains and turns colder, causing emergence problems. People tend to remember this as a “window” during which they should have held off planting until the forecast was more favorable. Such hindsight is usually good, but it’s rarely the case that the forecast is so accurate that waiting to plant, at least after the third week of April, turns out to be the best decision.

At the same time, as long as soil and air temperatures remain cool, the early-planting advantage will be smaller than usual this year. It takes about 115 growing degree days from planting to corn emergence. Fewer than half that many GDD have accumulated since April 1 in most of Illinois, and with daily accumulations in single digits this week (a low of 50 or less and a high of 60 degrees provides only 5 GDD), planted corn isn’t growing a lot faster than corn seed still stored in the shed.

While cool temperatures have slowed surface drying, April rainfall, with the exception of a number of counties in east central Illinois, has been at or below normal to date. That has allowed excess water to move out of surface soils, and once the weather starts to warm, the surface soil will start to dry and conditions for planting will improve quickly. We need to wait until the seedbed is in good condition, but if predictions hold, we could see planting begin by this weekend, and accelerate next week. There’s no great advantage to planting on April 30 instead of May 1, but a strong start to planting as April ends will do a lot to restore our hopes that the 2018 season will be a good one.

If we can plant either corn or soybean, next week, which crop do we start with? If two planters can run at the same time, “both” would be a good answer. If it has to be one or the other, I’d still give a small edge to corn, only because it can emerge a little more consistently than soybeans if plant into cool soils. If we don’t get heavy rainfall before emergence, though, both crops should get off to a good, albeit somewhat delayed, start.

Since my article last week in which I mentioned that some people had planted soybeans very early (mostly in mid-March) this year, I’ve received several more reports, some indicating that hundreds of acres of soybeans were planted that early. If any of those fields establish good stands, please let me know and we can record this as the miracle it would be. I also saw in the recent newsletter from the Illinois Crop Improvement Association that both warm and cold germination percentages of soybean seed are not as high this year as they were last year.

If soybean planting (and replanting) is into cool soils, it might be worthwhile to bump up seeding rates to account for the possibility of lower germination. If you know the cold score, you might consider dividing the desired plant population (say 115,000 per acre) by the cold score minus 5 points to give seeding rate; as an example, if the cold score is 85%, divide 115,000 by 0.85 – 0.05 = 0.8 to give a seeding rate of about 144,000. If a cold score isn’t available, divide by warm germination minus 10 instead. If planting into warm soils, divide by the warm germination minus 5 points to make the adjustment.


N Rate Calculator Updated

Last month (March 2018) we used data from 2017 N rate response trials to update the N rate calculator that provides best-estimate N rate guidelines for different regions and previous crops (corn or soybean) in Illinois. The updating process, which is currently being done by spring each year in Illinois, involves adding the new data and taking out some of the older data.

Many people understand the idea of using data from previous research to try to predict how a management factor will work the next time (in this case, in fields in 2018) – after all, that’s what applied research is all about. But responses to N are highly variable across even nearby fields within a year, and that can make it difficult to place a lot of confidence in the results as a predictor of what will happen the next year. Which N response curve from last year would we expect to do the best job of telling us how much N to use this year?

Let’s use the data from Illinois trials in which corn followed soybean in 2017 to illustrate this. These data (shown in Figure 1) represent a large amount of work; many of these trials were done on farmer fields, organized and conducted by Dan Schaefer of the Illinois Fertilizer & Chemical Association, and some are done within our N research projects at University of Illinois sites. Both IFCA’s and my research projects are supported by the fertilizer checkoff, administered by the Illinois Nutrient Research & Education Council.

Figure 1. Nitrogen rate responses of corn following soybean in 51 on-farm trials in Illinois in 2017. Yellow triangles show the calculated optimum N rate (EONR) and yield at that rate for that trial, and the green circles show the MRTN rate and the yield at that N rate.

In order to show actual corn yields at different N rates, Figure 1 has straight lines connecting the yields, each of which is an average over three or four reps at each N rate. To work with the data, we have the computer calculate a “best-fit” line for each set of data, and the equation for this line produces a smooth curve. That equation is also used to calculate what N rate is required to maximize yield, and what that yield is. We can’t possibly hope to set N rates so that one of them is the “best” rate – we have to produce the shape of the response defined by the actual data points, then work with that.

Each set of N response data shown in Figure 1 has two symbols associated with it. One is a yellow triangle that marks the N rate – and yield at that rate – where the last pound of N produced just enough additional yield to pay for that pound of N. We call this rate the “economic optimum N rate” or EONR. As a default, we often set the cost of 10 pounds of N as equal to the price of one bushel of corn – for example, N might be $0.40 per pound and corn $4.00 per bushel. In that case the EONR is the N rate at which the last pound of N produces a tenth of a bushel of yield. Above that N rate, the cost of added N is not covered by the additional yield; below that rate, each pound of N adds more yield than it takes to cover its cost. In both cases, the return to N is less than it is at the EONR.

Each set of response data also has a green circle (like the EONR triangles, many of these are not exactly on the line because the lines aren’t the fitted curves) that gives the “maximum return to N” (MRTN) N rate calculated by the N rate calculator (the 2017 version, which ran using data through 2016), and the yield at that N rate for that response curve. There are three vertical arrays of the green circles, each corresponding to the Illinois region in which the trials were conducted; MRTN values produced by the N rate calculator decrease from the north (those on the left) to central (middle set of circles) to southern (circles on the right) regions of Illinois for corn following soybean. The green circle shows how well using the MRTN rate would have done in that field in 2017 compared to what we now know (because we had an N rate trial there) was the actual best rate (the EONR, shown by the yellow triangle) in that field in 2017.

At first glance, the fact that the EONR values (yellow triangles) on Figure 1 are so spread out, and that most of them are not very close to the green circle on the same curve, looks like the MRTN rate failed to predict the best N rate for that field in 2017. Of the 51 sites, the actual EONR is to the right of the green circle – that is, the MRTN rate wasn’t high enough  – at 21 sites. At the other 30 sites, the MRTN rate was higher than the actual EONR – the yellow triangles are to the left of the green circles. Across all 51 trials, the average MRTN was 172 pounds N per acre, and the average EONR was about 168 pounds N per acre – the difference was only 4 pounds of N. The average yield at the MRTN rate was 226 bushels per acre, and at the EONR was 229 bushels per acre, or 3 bushels more. Using N and corn prices of $0.35 per pound and $3.50 per bushel, using the EONR (which, of course, we couldn’t have known before the season) in each field would have returned about $12.50 per acre more than using the MRTN rate in each field. The two sites with the highest EONR values (those farthest right in Figure 1) by themselves added almost 4 pounds to the average EONR value and almost $3 to the higher return from using the EONR. Though we seldom see such high EONR values, we leave them in the database because they represent possible (future) outcomes, and we can’t justify leaving them out.

Focusing on the yellow triangles in Figure 1 makes clear what we discovered some years ago – that there is no correlation between EONR and the yield at the EONR across a set of N response trials. In fact, a trendline drawn through the EONR values slopes down slightly, meaning that across this set of trials, higher yields needed a little less N than lower yields. The only explanation for this that makes sense is that moisture and temperature conditions that resulted in high yields also increased the amount of N provided by mineralization of sol organic matter, and may also have increased the ability of the roots to get access to that N. At the extremes, in one trial the yield was 278 bushels at 101 pounds of N, and in another the yield was 203 bushels at 226 pounds of fertilizer N. We estimate that corn needs to take up about one pound of N for each bushel it yields. If so, fertilizer provided only 101/278 = 36 percent of the N needed in the first trial, but 226/203 = 111% of the N needed in the second trial.

Even though on average the MRTN performed well in 2017, it clearly did not do so in every trial field, or even in most of these fields. This points out a fundamental difficulty that dogs every attempt to predict “best” N rates for a field or for different parts of a field: nothing we have been able to measure predicts with any accuracy how much N from fertilizer a given field will need at the start of a given season. With yield goal as a basis for N need pretty much sidelined by the finding that higher yields don’t need more N than lower yields, and with both yields and N responses highly influenced by (unpredictable) weather, what can we use to predict how much fertilizer N a field will need?

One such possibility is a way to predict how much N will come from mineralization of soil organic N, which by subtraction could help estimate how much fertilizer might be needed in a field. Another is a way to estimate how much N is lost due to unfavorably wet weather before the plant has a chance to take it up. These attempts have so far not been very successful; we still don’t have a way to know, in May or June, whether the crop in a field needs 120 pounds of N or twice that much to produce the yield it will produce this season. Our best guess today is the MRTN, perhaps tweaked up or down depending on circumstances. Each MRTN value has a range of about 15 pounds of N on either side over which we expect return to N to be very close (within $1 per acre) of the return at the MRTN.

Updating the N rate calculator with recent data and dropping out some older data doesn’t change its output by very much in Illinois, because we have so much data already there: there are 267 N responses for corn following soybean in the database for central Illinois alone. The update this spring added about 3 pounds of N to most MRTN values using current N and corn prices. At $500 per ton of ammonia and with corn at $3.85, the MRTN for corn following soybean in central Illinois is 183 pounds per acre. That rate is expected to produce 99% of maximum yield; by definition, the optimum N rate never produces maximum yield because the last N has to pay for itself, and only if N were free would that be at the rate needed to produce maximum yield. The range over which the return to N would be expected to be within one dollar per acre of the maximum is 168 to 200 pounds of N per acre.

Other numbers produced by the calculator include the cost of N at the MRTN ($54.90/acre), the amount of material needed (223 pounds of ammonia), and the net return to N at the MRTN ($314.62 per acre.) Note that the calculator subtracts the yield without N from each N response – the return to N is only the yield added by fertilizer N times the corn price minus the MRTN N rate times the price of N. With the N cost of $54.90 per acre and the gross return of $314.62 + $54.90 = $369.52, we can calculate that this amount of N increased yield by $369.50/acre ÷ $3.80/bushel = 97 bushels per acre. The “true” nitrogen use efficiency (NUE) is the MRTN divided by the amount of yield added by N, or in this case 183 lb. N/acre ÷ 97 bushels/acre = 1.9 pounds of N for each bushel added from using N fertilizer. We often just divide N rate by yield for a field because we can’t know what the yield was without N, so when yields are high and N rates reasonable, we typically have NUE values of only 0.7 or 0.8 lb. N per bushel. That’s helpful in that it helps us see that we don’t need such high N rates to get high yields. But it includes the N supplied by the soil, not just that added as fertilizer.

Stripe Rust in S. Illinois

I received notice of stripe rust in S. Illinois today.  Stripe rust is an important disease affecting wheat.  Please find an article on this disease and management by clicking here.  

If you locate stripe rust in your field please tweet a picture to me (@ILplantdoc) or email ( with the wheat variety, growth stage, and approximate percent of field infected.  This information will be useful to IL wheat producers this year and in upcoming seasons.

An example of a stripe rust in wheat. Photo N. Kleczewski 2016

Early-Season Management of Soybean

If the old saying that rain on Easter means that it will rain on the next seven Sundays applies to snow, we’re in trouble – it snowed across a wide swath of Illinois on Easter Sunday (April 1) and also on April 8.

We had enough dry weather in March to allow some ammonia to go on early, but there has been little opportunity for field work over the last six weeks. Rainfall over the past month has been below normal for the northern third of Illinois and above-normal in the southern half of the state, especially along I-70. Even though it’s not sopping wet in many areas, below-normal temperatures in recent weeks means very slow drying of soils. While we know that conditions can change quickly – even as I write this the forecast has improved for the rest of this week – it’s clear that the spring of 2018 is not going to be one that allows a very early start for field operations.

Soybean following soybean

With soybean acreage in Illinois expected to increase some and corn acreage to fall this year, some soybeans in 2018 will follow soybeans. As I’ve written before, there is no particular concern in planting soybeans after soybeans, except perhaps to avoid doing this if soybean cyst nematode egg counts are high. We have no reason to expect that SCN counts are unusually high, but if this will be the third year of soybean in the same field or if there was any hint of SCN damage in the 2017 crop, it might be worth taking a count yet this spring. SCN-resistant varieties are a must in any case.

The yield penalty for soybeans that follow soybeans instead of corn varies some by site and year, but most of our research shows this penalty to be modest, usually less than 10%. Averaged over three trial sites and two years (2016 and 2017), soybean following: 1) continuous corn yielded 76.9 bushels per acre; 2) two years of corn yielded 71.4 bushels; 3) one year of corn yielded 69.2 bushels, and; one year of soybean yielded 68.0 bushels per acre. In 2017 we had soybean following two years of soybean, and averaged over three sites, these yielded about 2.5 bushels less than those following one year of soybean.

In two long-running studies in western Illinois, tillage has had either no effect on yield of soybean following soybean, or has decreased yield. If the soybean stubble was not tilled last fall, it would probably be better to plant soybeans without tillage this spring. We did see a slow start to no-till soybeans under the cool, wet conditions of 2015, and at the Monmouth site that year, no-till soybeans following soybeans yielded 5 bushels less than tilled. This differences was even larger in soybean following corn that year. Soybean following corn tends to yield a little more when tilled than with no-till, in fact, though the difference averaged over years is not enough to pay for tillage operations.

Other than normal scouting for disease and weed management, though, there are few other management considerations specific to growing soybeans after soybeans.

Cover crop management

Cereal rye planted into corn stalks last fall has made much less growth than normal, especially in comparison to 2017, when February temperature averaged nearly 10 degrees warmer than in 2018 and the cover crop grew for a couple of months before April. The slow growth this year will continue as long as soil temperatures remain in the upper 30s to low 40s as they are now. But rye is a cool-season crop, and will start to grow rapidly once it warms up.

Conditions have not been good to kill the cover crop with herbicide, so slow growth may be preferable to rapid growth for now. But a choice will need to be made in the coming weeks about how long to let the rye grow before spraying to kill it. We want enough growth to produce the benefits for which we planted the cover crop, but we also need to manage it so it doesn’t interfere with soybean establishment. If soybean seed can be placed into soil well, this shouldn’t be a big concern. But as long as the weather and soils stay cool, soils will dry slowly, especially once the rye is killed and is no longer taking up water. Lower amounts of residue due to slow growth will help some, but soybean seed placement and crop emergence could still be a challenge, especially if soils continue to dry slowly or the weather turns wetter. Clearing residue off the row will help, if that’s an option.

Planting date

In the spring of 2017, soil conditions and temperatures were so favorable early that some people planted a “test” area of soybeans in February to see how they’d do. They did well – soybean are quite tolerant of frost as long as they haven’t emerged yet or have emerged and their “neck” has straightened out to bring leaves and cotyledons to the horizontal. So the period in mid-March with temperatures in the 20s last year didn’t kill the crop, and some of these soybeans yielded as much as those planted in late April.

This year, soils in some areas were dry enough to plant by mid-March, and some people again planted soybean then. [Some corn got planted as well, but that no longer attracts the attention that super-early soybean planting does.] Conditions since have been much less favorable than they were a year ago, and this has kept the early-planted crop from emerging, at least in most fields. Only about 30 growing degree days (base 50) have accumulated over the past month at Champaign – that’s maybe a fourth of the number of GDD needed for the crop to emerge. It will be surprising if soybean seed that has been in cold, wet soils for the past month is still viable, but we won’t know for sure until soils warm up. For the curious, digging up seeds and putting them in a damp paper towel in a warm room for a few days will show whether they’re still alive. Even if they’re alive there’s no guarantee that they’ll be able to emerge and become healthy plants.

Lost in the attention given to the survival of soybeans planted very early is the question about such early planting – provided the crop survives – affects soybean yield. Given how rare it is that soybeans can be planted by or before mid-March, we have not done trials on this. We mostly have anecdotes, and those may be skewed towards those times when the crop survived. We have seen a few cases, especially in the very dry spring of 2012, when planting in early April was followed by stressful (cool or dry) conditions that limited plant height and yield compared to soybeans planted later. Even if soil conditions allow a March-planted crop to emerge, there is virtually no chance that it will yield more than a crop planted in the same field in late April, and some chance (if it survives) that it will yield less.

Overall, our data across 26 soybean planting date trials show that soybeans produce full yield if planted anytime between the second week of April and the end of April. The rate of yield loss with planting delay accelerates into May, reaching about 2/10ths of a bushel per day by the end of the first week of May, a quarter of a bushel per day by mid-May, a third of a bushel by the end of May, and 4/10ths of a bushel per day by June 10. These are lower loss rates than we often see presented elsewhere, most of which are based on a limited number of trials. That doesn’t mean we shouldn’t try to plant as early as we can to get full yields, but it does show what most farmers know from experience – that high soybean yields depend more on what happens during the season than on when the crop gets planted, although planting by mid-May increases the chance that the crop will be able to respond to favorable conditions later. A corollary to that observation is that planting soybean into poor soil conditions just to get them planted early can decrease the ability of the crop to respond to favorable conditions later, and thereby end up costing yield.

Seeding rate

While 100,000 or even fewer plants per acre will maximize yield in many cases, our research shows that this is not always enough plants. Trying to minimize the seeding rate can end up costing yield and losing money, especially in those cases when emergence and stand establishment are lowered by conditions at or after planting. While responses to plant stand do vary across trials, we have found that 115,000 to 120,000 plants (not seeds) per acre are often needed to produce the highest dollar return on the seed investment. If we plant good seed into good conditions we can expect 85% stand establishment, in which case we should plant about 140,000 seeds per acre, which for most seed companies today is one unit of seed.


Despite that fact that most trials in Corn Belt states in recent years – including our trials in Illinois – have shown little or no yield increase from applications of 45 to 90 pounds of N (100 to 200 pounds of urea) during the growing season, this practice continues to draw a lot of interest. In a set of trials we just finished, applying 45 or 100 pounds of N at planting time produced large increases in yield two years in a row on an irrigated loam soil near the Illinois River at Chillicothe, Illinois. Planting-time N had no effect on yield in most other trials in heavier, higher-organic-matter soils. We did find yield increases in a number of trials when we applied the same amount of N four different times, from planting through early podfilling. While repeated use of N may help explain some “contest” yields, the yield increase from four applications was not enough to pay even half the cost of these applications. Putting that much N on also means a lot of N left in the soil at the end of the season, so more N loss through tile.

With so many voices today claiming that N application on soybean “can” increase yield and others saying that it still won’t increase profits, what should producers do? In an ideal world, 500 Illinois farmers would put out a set of N strips (next to strips without N) in a field or two each year, and results would be brought together to produce data-backed expectations of how profitable this practice is on different soil types and across years. One of the reasons that’s difficult today is that so many soybean fields are harvested on an angle to the rows, making yield data collection difficult or impossible. There is also no one to organize such work and little noticeable interest by those who might fund such a project. “Trying” N by applying it to a field or two is sometimes suggested by those who feel that this is a profitable practice. This approach, of course, provides no information on whether or not applying N did anything.

For those interested in a “lite” N trial on soybean

Both times that we’ve seen a large yield increase from N on soybeans were on lighter-textured soil with N applied at planting. Applying N at planting typically makes leaves and cotyledons of small plants darker green in color compared to plants without N. In cases where N ends up increasing yield, this darker green color persists into vegetative stages, and plants tend to show increased growth and more green through most of the rest of the season. Where planting-time N doesn’t increase yield, the difference in green color between plants with N and those without N disappears as the plants make vegetative growth, and as their roots get more access to N from the soil and from N fixation in nodules. By the time plants are 6 to 8 inches tall, the effects of planting–time N are often no longer visible.

Based on what we’ve seen, I’m suggesting a low-cost alternative to large-scale application of N as a way to see where and how often N might have the potential increase soybean yields. Here’s the outline:

  1. After planting and before emergence, choose a uniform spot at least 20 feet away from endrows or edge of the field, and put flags in the corners of an area 15 feet x 15 feet square. We expect to see N effects more often on soils that are lighter in texture and lower in organic matter, so place this accordingly, in two or three fields or parts of fields with contrasting soil types if that’s an option. If possible record GPS coordinates for each site.
  2. Weigh out enough N fertilizer – urea or lawn fertilizer (without herbicide) – to provide 50 pounds of N per acre on the 225 square feet you flagged out. Calculate this by dividing the number 25.83 by the percentage of N in the product (urea may be 46-0-0, or 46% N; lawn fertilizer might be something like 27-0-4, or 27% N) to give the amount of product needed. As an example, if using urea (46% N), you would need 25.83/46 = 0.56 lb. of product. Multiply this by 16 to get number of ounces, or by 453.6 to give number of grams, if you have a gram scale. If you have a measuring cup but not a scale, urea weighs roughly 3/4ths as much as the same volume of water, so a cup (8 fluid ounces) of urea weighs about 6 ounces.
  3. Apply the fertilizer carefully, by hand or using a hand spin-spreader, uniformly over the soil inside the square.
  4. The “data” to be taken can, for most people, just be a photograph with the image split between the area with N and an area (outside the square) without N. I suggest taking a photo at about the V2 stage (two full trifoliolate leaves present), and another one about a month later, at perhaps V6-V7, when plants may be a foot tall or so. Find the side of the square that gives the best contrast under existing light conditions. Feel free to supplement the photo by noting what you can see (or not see) by eye.
  5. If the second photo shows no difference in greenness of plant size between those that received N and those that didn’t, the experiment could end there, with the conclusion that N probably made no lasting difference on growth, and so is unlikely to increase yield. If the plants with N are still greener and/or larger than those without N, that would be a signal to come back once or twice more, to see if the differences persists to the podfilling stages in mid- to late August, and again before leaves drop.
  6. If plants inside the treated square are visibly different than those outside, and there’s enough ambition and curiosity, you could harvest 15 or 20 randomly-selected plants inside the treated area and outside the treated area, and take a photo with the two sets of plants next to one another to show any visual effects on height or pod number. Those interested could count the number of pods, or even thresh the plants (in burlap bags works best) and weigh seed to estimate yield. Calculating yield would require an estimate of number of plants per foot of row. Yield estimated this way are highly variable, so they may not line up with what we thought we’d see based on plant size and appearance.

I’d be happy to look at photos from such comparisons; if there’s enough interest I could also develop a small reporting form to make a record for each trial. I’ll also be glad to send a layout for anyone interested in doing a strip trial with and without N. I can be contacted by email (link below, on my name) or my cellphone number is (217) 369-1997.


Last call for soybean information

I wrote a short article here about a month ago asking for everyone’s cooperation on a project in which we (Corn Belt states) are gathering field-level information on soybean fields to feed into a study, funded (with soybean checkoff dollars) by the North Central Soybean Research Program, looking at weather, soil, and management effects soybean yield over the Corn Belt.

While we got some response to that article, we have so far gathered information on less than half the fields in Illinois that we, as the largest soybean-producing state, are assigned to get from the 2017 growing season. After distributing hundreds of the forms and describing the project at meetings around Illinois over the past month, this is both disappointing and perplexing. I’m asking for everyone’s help to get more of this information collected in the final push over the next couple of weeks.

As we have done for the last year, we are offering a $50 gift card for those who fill out and return forms. Our focus is on the 2017 season, but we will accept information from 2016 as well. We don’t ask for detailed information – only the location of each field, field yield (just a number, no map), and some production information such as planting date, seeding rate, etc. We’d like information on up to four fields from each of the past two seasons from each producer, but information from only 2017 can also be provided. The gift card request form mentions that we’d like information from at least six fields over the two years, but we’ll be happy to provide gift cards for information on three or four fields, and only from 2017.

If you can help us in this effort, please download the PDF forms at – there are four pages, one an example with a little explanation, one is the gift card request form, and there is one page each for 2016 and 2017, with space on each for information from up to four fields. I can send also forms by mail of email if anyone needs that.

Forms can be filled on the computer or printed and filled out by hand, then scanned and returned as email attachments, or sent by mail. The mailing address is on the gift card request form.

The last date we can receive forms is March 31 – we will need to send in what we have no later than April 2 (April 1 is Easter Sunday.) So if you’re mailing completed forms, please send them by March 28 so they’ll arrive here on time. We may not be able to use (or provide gift cards for) any forms postmarked after April 1.

I’d really appreciate everyone’s help to reach our goal this last time. We need information from fields all over Illinois. Students, vo-ag classes, farmers, company agronomists, sales people – all can help with this effort. If you know anyone who might be interested, please pass this request on.

Thanks to all who have helped on this project, and in advance to those who will respond to this appeal.

One More Call for Soybean Production Information

A number of times over the past 30 months I’ve asked Illinois soybean producers for help in gathering field-level information on soybean fields to feed into a study, led by the University of Nebraska and funded by the North Central Soybean Research Program, looking at weather, soil, and management effects soybean yield over the Corn Belt.

The last growing season from which we are collecting information is 2017, so this is probably the last time I’ll ask. As we have done for the last year, we are offering a $50 gift card for those who fill out and return forms from 2016 and 2017.

We are not asking for detailed information – only the location of each field, yield level, and a little production information such as planting date, seeding rate, etc. We’d like information on four fields from each of the past two season from each producer if possible.

If you can help us in this effort, please download the PDF forms at – there are four pages, one an example with a little explanation, one is the gift card request form, and there is one page each for 2016 and 2017, with space on each for information from four fields. If it’s easier, you can email me and I’ll email the forms . We can send also forms by mail if anyone needs that.

Forms can be filled on the computer or printed and filled out by hand, then scanned and returned as email attachments or sent by mail.

We have fallen short of the number of fields in this project each of the first three years, and I’d really appreciate everyone’s help to get to reach goal this time. We’d like information from fields all over Illinois. Students (who might have special interest in the gift card), vo-ag classes, farmers, company agronomists, sales people – all can help with this effort.

Thanks in advance for your help on this. Let me know if you have questions.

2018 Crop Management Conferences Registration Open

Registration is open for the 2018 Crop Management Conferences. These regional conferences provide a forum for discussion and interaction between participants and university researchers. We are looking forward to introducing new specialists from the University of Illinois, and have adjoining state specialists joining us at Mt. Vernon and Malta. We will also be offering dicamba training at the conclusion of each conference.

Certified Crop Advisers can earn up to 8 hours of continuing education credit. Advance registration, no later than one week before each conference, is $100 per person. Late and on-site registration is $120. Dates and locations along with a link to location-specific agendas and online registration are listed below.

January 24 – Mt. Vernon – DoubleTree by Hilton

January 31 – Springfield – Brookens Auditorium – UIS

February 7 – Champaign – I-Hotel

February 21 – Malta – Kishwaukee College


2018 topics include:

  • Insect Management in Corn and Soybeans – Dr.  Nick Seiter, University of Illinois,  Department of Crop Sciences
  • How Do We Measure Success with Dicamba in 2018?  – Dr. Aaron Hager, University of Illinois, Department of Crop Sciences  (Mt. Vernon , Springfield, Champaign)
  • New Things Floating Around in the World of Weed Management – Dr. William Johnson, Purdue, Department of Botany and Plant Pathology (Malta)
  • Crop Economics in a Continuing and New Normal Price Environment – Dr. Gary Schnitkey, University of Illinois, Department of Agriculture and Consumer Economics
  • Chippin’ Away at Nitrate Loss with Woodchip Bioreactors – Dr. Laura Christianson, University of Illinois, Department of Crop Sciences
  • Introductions and Updates in Field Crop Diseases – Dr. Nathan Kleczewski, University of Illinois, Department of Crop Sciences (Springfield, Champaign, Malta)
  • Managing Winter Wheat for Profitable Yields – Dr. Carrie Knott, University of Kentucky, Department of Plant and Soil Sciences (Mt. Vernon)
  • Designing Crops of the Future for Maximum Efficiency and Productivity – Dr. Anthony Studer, University of Illinois, Department of Crop Sciences  (Mt. Vernon, Springfield, Champaign)
  • Identification and Management of the Yield Gap in Soybean – Dr. Shawn Conley, University of Wisconsin, Department of Agronomy (Malta)
  • Explaining the 2017 Growing Season – Dr.  Emerson Nafziger, University of Illinois,  Department of Crop Sciences

In early October 2017, the EPA approved revised labels for Xtendimax, FeXapan, and Engenia. In addition to being classified as restricted use pesticides, the labels now require applicators to attend an annual dicamba or group 4 herbicide-specific training prior to using the products. At 4 pm at each Crop Management location, a 60-minute “Dicamba Training for Illinois” provided by industry educators will be available. This training will meet the new educational requirements.

Precautions for Dicamba Use in Xtend Soybeans

The extension weed science programs at The Ohio State University, Purdue University, and the University of Illinois recently collaborated to produce suggestions and precautions for use of dicamba in dicamba-resistant soybean.  The United States Environmental Protection Agency issued amendments to the Xtendimax, Engenia, and FeXapan labels last October, and this new extension weed science publication offers additional suggestions to help further reduce off-target dicamba movement.  Dicamba Precautions

Timing Fall Nitrogen

The substantial rain that fell over central and northern Illinois between October 5 and 15 mostly soaked into the soil that was dried out by crop water use, and harvest has moved back to full speed in most areas. With harvest, thoughts turn to application of fall ammonia in central and northern Illinois. Almost everyone is on board with waiting until soil temperatures are at or below 50 degrees before applying ammonia. Cool soil (along with use of nitrification inhibitor) lowers the rate of nitrification, so helps preserve N in the ammonium form. Nitrogen present in the soil as ammonium is safe from loss.

Once air and soil temperatures start to decline in October, it’s natural to anticipate that soil temperatures will reach 50 soon, so some are inclined to start to apply before soil temperatures reach 50 degrees. But if we apply when soil is at 60 degrees and soil temperatures fail to drop quickly, or if they rise again after application, nitrification will continue and will persist as long as soils stay warmer. In fact, nitrification does not stop dead at 50 degrees; as a biological process, its rate drops off as temperature falls, but temperatures need to near freezing for nitrification to stop completely.

So we need to wait to apply fall ammonia not only until soil temperatures are 50 or less, but until we have reasonable confidence that they’ll stay there. In Illinois, we normally consider November 1 to be the date at which we can be reasonably sure that soil temperatures won’t rise again until the next spring. That’s not a sure thing, however – in both of the past two years, soil temperatures have gone above 50 at least once between November and February. But most years it’s a reasonable starting date to balance keeping N safe with getting fall application done.

Minimum air temperatures have fallen into the 40s this past week, which has people wondering if it might be OK to go ahead and start applying now. Minimum soil temperatures 4 inches deep under bare soil (from the Illinois Water Survey have dropped to the upper 40s to low 50s over much of the state each day between October 16 and 18 this week. The problem with using only the minimum soil temperature is that it doesn’t represent the actual soil temperature in the ammonia application zone. As Figure 1 shows, minimum soil temperatures (on clear days) are typically five degrees or so less than average soil temperatures for the day. So even though we may need a jacket on cool mornings this week, ammonia applied now is not going to be in soils with temperatures less than 50 degrees for some days or weeks.

Figure 1. Soil temperature at 4 inches under bare soil at three Illinois Climate Network sites on October 17, 2017. Source: Illinois State Water Survey.

Figure 1. Soil temperature at 4 inches under bare soil at three Illinois Climate Network sites on October 17, 2017. Source: Illinois State Water Survey.

Air temperatures are forecast to stay in the 70s the rest of this week, to fall into the 50s (with lows in the mid to upper 30s) next week, then to rise again (with dry weather) for some period after that. We’re already past the average first frost date for central and northern Illinois, and even with more seasonal temperatures coming the last week of October, it doesn’t look like ammonia applied now will be as safe from nitrification and possible loss as will ammonia applied in November.

If the soil is in condition to apply ammonia, soil temperatures are in the upper 40s, and the 10-day forecast doesn’t show above-normal temperatures settling in, the last few days of October might offer an opportunity to start applying ammonia. But what if early November is warmer than normal, and soil temperatures remain above 50? Delaying application, of course, moves us closer to having safer soil temperatures.

Average Illinois fall temperatures have been trending slowly upward for some decades now, and as we have seen the last few years, waiting until November 1 does not assure low soil temperatures as consistently as it did in the past. So if a stretch of warm weather is still in the forecast at the end of October, it might make sense to wait a little longer. Otherwise, patience in waiting another 10 days will likely be rewarded, even if – as is often be the case when doing the right thing – the reward isn’t very visible.