Destructive diseases of soybean – sudden death syndrome and white mold – observed in the state

Signs and symptoms of a few soybean diseases have begun to show up in the last few weeks in some areas of the state.  Two of these diseases, sudden death syndrome (SDS) and Sclerotinia stem rot (a.k.a. white mold) certainly are going to cause economic losses in some growers’ fields this year.

Symptoms of SDS that currently are being observed are interveinal chlorosis and necrosis of the leaves (veins remain green while the tissues between the veins turn yellow and then brown).  These symptoms look exactly like the foliar symptoms caused by a different disease, brown stem rot.  Brown stem rot, however, will cause internal browning of the pith in soybean stems, while SDS does not affect soybean stems.  On SDS-affected plants, the leaves will fall off eventually, while the petioles will remain attached to the stems and branches.  In some cases, a bluish-white mass of spores of the SDS fungus (Fusarium virguliforme) may be observed on the roots.  Although the foliar symptoms of SDS are now being observed, infection by the SDS fungus occurred during the seedling stage, not long after planting.  The symptoms that are now being observed are the effect of toxins that the SDS pathogen produces that are phytotoxic.  Cool and wet weather after planting and the recent rainfall received in parts of the state were favorable for infection and disease development, and are the reasons why SDS incidence is high in some areas this year.  The primary method of managing SDS is to choose the most resistant soybean varieties available.  Some evidence has shown that high soybean cyst nematode (SCN) egg populations may also increase the likelihood of severe SDS; therefore, managing SCN populations through resistant varieties and crop rotation may also reduce the risk of SDS.  Unfortunately, there currently are no fungicide products registered that are effective in managing SDS, but an experimental fungicide seed treatment known as “ILeVO” that is currently making its way through the EPA registration process has shown efficacy against SDS in University of Illinois field trials.

Symptoms of sudden death syndrome of soybean (Photo by C. Bradley).

 

A bluish-white mass of spores of the SDS fungus (Fusarium virguliforme) on a soybean root (Photo by C. Bradley).

 

White mold can be observed in fields located in the northern half of Illinois this year.  The appearance of this disease also is weather-related.  Areas in the northern half of the state, that were cooler and wetter than normal after soybean plants began to flower, are the areas that are affected the most severely.  Unfortunately, once white mold signs and symptoms are detected in the field, fungicide applications generally will be futile, as the damage has already been done.  Management of white mold was discussed in an earlier article of the Bulletin this year (http://bulletin.ipm.illinois.edu/?p=2412).  Growers with severe levels of white mold may encounter some discounts at the elevator this year for high levels of foreign matter.  Some sclerotia (dark survival structures produced by the white mold fungus – Sclerotinia sclerotiorum) that are formed on plants may similar in size to the seed, and will make their way to the hopper and eventually the elevator, where discounts may be received.

 

Soybean plants dying prematurely because of white mold in a field in Champaign County (Photo by K. Ames).

 

White mycelia of the white mold fungus (Sclerotinia sclerotiorum) on a soybean plant (Photo by C. Bradley).


2014 Ewing Demonstration Center Fall Field Day

2014 Ewing Demonstration Center Fall Field Day

The University of Illinois Extension will host its annual Ewing Demonstration Center Fall Field Day on Thursday, September 11, 2014 at 9 a.m.  The Ewing Demonstration Center at is located at 16132 N. Ewing Rd; Ewing IL 62836, on the north edge of the village of Ewing, north of the Ewing Grade School on north Ewing Road.  Watch for signs.

The ongoing research plots this year consist of a soybean cover crops trial, LibertyLink soybean variety trial, insecticide/fungicide trial on soybeans, corn population study, drought tolerant corn hybrid evaluation, and new this year a pumpkin variety trial.

 

The topics to be discussed at Field Day include:

Fusarium Head Blight (Scab) and Vomitoxin Management in Wheat

  • Carl Bradley, Extension Specialist, Plant Pathology, University of Illinois Extension

Sky High Crop Scouting; Unmanned Aerial Drones

  • Dennis Bowman, Extension Educator, University of Illinois Extension

Alternative Forages and Harvesting Methods

  • Teresa Steckler, Extension Educator, Commercial Ag, University of Illinois Extension

Palmer Amaranth: Coming (Soon) to a Field Near You

  • Robert Bellm, Extension Educator, Commercial Ag, University of Illinois Extension

Cover Crops and Weed Management

  • Nathan Johanning, Extension Educator, Small Farms Local Foods, University of Illinois Extension

Refreshments will be provided by Franklin County Farm Bureau.

The field day is free and open to anyone interested.  A light lunch will be provided and registration is recommended by September 8, 2014 for an accurate meal count.

For additional information or to register, contact Marc Lamczyk at University of Illinois Extension Office in Franklin County at 618-439-3178 or lamczyk@illinois.edu.

 


Did We Miss the Boat on Corn Plant Population in 2014?

One of the speakers at the UI Agronomy Day at Urbana this past week was quoted as saying that corn producers had not planted enough plants this year to take advantage of the good growing conditions. The assertion was that 45,000 plants would have been more appropriate than 32,000 plants. Most produces are planting more than 32,000 now on more productive fields. But few are pushing populations into the mid-40,000 range, at least on a lot of acres. Did we all miss the boat by planting “only” 35,000 or 36,000 seeds this year?

Fortunately, we have a lot of data to help answer this question. Since 2011, we have been running trials at a dozen sites around Illinois in which we plant 6 to 8 hybrids at a range of populations, including planting rates of 34,000 and 42,000. Plant counts show that actual stands are very close to planted populations. Counting each hybrid at each site each year as a comparison, we have accumulated 277 comparisons of 34,000 and 42,000 plants over the past three years.

Figure 1 shows all of these data, graphed to compare the yield change when going from 34,000 to 42,000 plants against the average yield at the two populations. On average the difference in yield between these two populations was only about a tenth of a bushel, and there was no indication that the response got larger as yield level increased; in fact, the line drawn through the points shows slightly lower yield differences as yield level increased.

 

Figure 1. Corn yield difference between 34,000 to 42,000 plants per acre in 277 comparisons in Illinois trials, 2011-2013.

At yield levels less than 150 bushels per acre, 42,000 plants yielded 9 bushels more than 34,000 plants, with a range of -62 to +48 bushels. At yields above 250 bushels per acre, 42,000 plants yielded a half bushel less than 34,000 plants, and the range was -24 to +24 bushels. This reinforces what many of us know – that low-yielding conditions tend to make yield less consistent, with more differences due to factors like hybrid stress tolerance water-holding capacity within fields.

These data give no support to the idea that a corn crop planted at populations in the mid-30,000 range is incapable of taking full advantage of high-yielding conditions. The data also confirm that risks of having populations too high for the conditions increases when we don’t have conditions for high yields.

Because we don’t know what conditions will be at the beginning of the season – the 2012 season started off great and would have been a “good” season to raise populations at planting – it makes no sense to push populations above 40,000 in hopes that we’ll get the weather to make this pay off. In fact, the response of yield to population tends to be fairly flat over the range of the lower to the upper 30,000s, regardless of yield level or conditions.


A Good Crop Takes Shape

The “walls” of dark green corn as the crop begins its push to fill grain and make yield is always an inspiring sight, and the 2014 crop is the best I’ve seen at stage of development. It’s been almost this good in June several times, but not at the end of July. The crop condition rating has been stuck at about 80% good to excellent, and this remarkable uniformity is apparent in travels around northern and western Illinois in recent weeks.

The same is true for the soybean crop, though the condition rating isn’t quite as high, and there are areas where the crop doesn’t look great.

Without many serious problems to look at, this is a good time to consider whether this crop will turn out to be as good as it looks, and what threats might linger as we move into the 6 weeks over which yield will be made:

  • Nitrogen: Despite a lot of rainfall in May and June (into early July in some places), the deep green color of the corn crop in most fields tells us that the crop is well-provided with nitrogen. While water moving through the soil has undoubtedly moved some of the nitrate deeper, the fact that adequate N has clearly been taken up has to be a consequence of having a healthy root system that is active deep enough to take up what N is there. Plots without N in rate trials are very deficient, probably due to both downward movement of N and root systems that are feeble due to poor N nutrition and growth of the crop. But the crop is green all the way to the lower leaves in fields with normal N rates, and so we don’t anticipate that the 2014 crop will require more than normal amounts of N. Recent N Watch samples show that soil nitrate values have dropped considerably over the past month, but that’s as is should be – we apply fertilizer N for the crop, not to accumulate in the soil. Uptake of N by the crop has slowed considerably as the crop moves past pollination, and we see little reason to worry about having enough N in the soil now. Mineralization of organic matter is providing N that will serve as backup, but the crop has taken up 80 to 85% of the N it will take up by the end of the season. Stress from hot, dry weather is about the only threat to the N status of corn plants beyond this point in the season, and with another stretch of cool weather coming now, chances of having this happen in time to hurt yields are diminishing
  • Water: I’ve likened the corn crop this year to last year’s crop about 10 days later than this; the 2014 crop was planted earlier and had normal temperatures through June, plus enough water to make good growth and to reach at least normal height. Excess water has certainly done some damage in some fields, and in cases the roots in low areas that were flooded for a week or more, they (and crop prospects in those areas) are damaged to the point where they won’t recover much. In 2013, there was in some areas little rainfall after August 1 all the way to crop maturity; the soils had to have provided the 8 inches or more of water required to fill grain after the milk stage of kernel development. This year, soil water is in better supply than it was at the beginning of August last year, and the cool conditions over the coming weeks will help stretch the water supply even further. The crop might benefit from some additional rainfall within the next month, but highs of only 80 or so plus lots of sunshine are excellent conditions for corn grainfilling, and with roots that have done a good job up to now, we don’t see much danger of having the crop run out of water.
  • Kernel number: We cannot produce good corn yields without high kernel numbers, even though in very good years kernels often get larger than they would otherwise. A starting point is maybe 15 million kernels per acre, which at 75,000 kernels per bushel (such kernels are a little above average, but not huge) would produce 200 bushels per acre. At 35,000 ears per acre, it takes only about 430 kernels per ear to make 15 million per acre. That’s not a large ear – at 16 rows of kernels, it’s only 27 kernels long. At 14 rows of kernels, it takes 4 more kernels per row to get to the same count. Someone recently mentioned the disappointment of finding ears with only 14 or 16 rows of kernels; it seems that people like to see 18 or 20 rows. The number of rows of kernels is influenced much more by hybrid genetics than by conditions in the field, and fewer rows are typically compensated by having more kernels per row, so have similar numbers of kernels per ear. This year, we may see kernel number approaching or exceeding 20 million per acre, which at 35,000 ears per acre would be 570 kernels per ear. At 14 rows that’s about 40 kernels per row, still easily within range of possibility. Kernel abortion should be less than normal, so kernels we can count by the time silks are brown will be mostly retained into grainfill, with any effect of stress late in the season seen as a reduction in kernel size.
  • Ear number: Stands are mostly good and ear numbers should be as well. There have been some reports of more than one ear per plant, including what Dr. Bob Nielsen calls “multiple ears on the same shank” or MESS (see http://www.agry.purdue.edu/ext/corn/news/timeless/MessyEars.html). The second (or third) ear on the same shank usually doesn’t produce kernels. In contrast, having ears at two separate nodes, with both producing grain, is the way that some hybrids today cope with having more than usual amounts of resources (sugar from photosynthesis) available before and at the time of pollination. Many older hybrids respond to this by increasing ear size, up to 800 or more kernels. Many hybrids today form a second ear instead. Making two smaller ears instead of one big one carries a little high “construction” cost, but with a shorter path from the stalk to the tip kernels, two smaller ears may have some advantage in getting the kernels filled if filling conditions are very good. To estimate yield potential of there are a lot of second ears, kernels per plant should be counted, with kernel size perhaps adjusted downward slightly if there are more than 750 or so kernels per plant. Should populations have been higher if there are 700 or 750 kernels per plant? Perhaps, but that many kernels may end up smaller, and not yield much less than more plants with fewer kernels each.
  • Canopy: If you can see down rows of corn, a good canopy will have healthy leaves interlaced to intercept nearly all of the sunlight, and you’ll find little light hitting the soil surface when the sun is high. If the crop gets enough water to maintain this canopy up to close to the end of grainfill, kernels will approach their maximum size (which has been determined by now in most fields, and with good conditions at pollination is likely to be large) and yields will be high. The corn crop needs about 1,300 growing degree days from pollination to maturity (black layer). At normal temperatures from mid-July into September, we get about 24 GDD per day, so getting 1,300 GDDs takes about 55 days. With temperatures on the cool side, at 55 nighttime and 80 daytime, that’s 17.5 GDD per day and it takes some 70 days to get to 1,300 GDD. With pollination nearly completed now, the crop should reach maturity by late September even if it stays this cool, but some warmer temperatures would be welcome, as long as it doesn’t go to the mid-90s and stay there. Cool nights are good, but 60 or 62 instead of 55 degrees would probably help more than hurt.
  • Standability: Having lots of kernels and conditions for potentially high yields often brings concerns about whether high yields might mean stalk quality problems later in the season. It is certainly the case that in the competition for sugars between developing kernels and stalk tissue, stalks usually lose. But when conditions are very good after pollination, as they were in 2013, plants are able to allocate enough sugars to help stalks deposit lignin, which is the woody material that gives stalks strength and helps keeps them standing even after the stalk tissue dies. So while there’s always some cause for concern about the possibility of high winds and downed corn, I see no reason for much alarm because we expect high yields.
  • So how high will yields be? This is the point at which we should humbly admit that we don’t know everything about the corn crop, that every year is different, and that we don’t want to guess. Facts in favor of a new record corn yield in Illinois in 2014 include a crop that’s in great shape now, above-average soil water stored in most areas, and lack of any evidence that a blocking high will set up to bring hot, dry conditions in time to shorten the filling period by much. But such hopes aren’t always realized, and it remains safer not to speculate on final yields.

I’ll continue the story on soybeans later, but will only note here that the dry weather we’ve had in recent weeks has been favorable for the early-planted crop, which had been starting to show signs of making the large leaves and tall plants that we have in the past found to produce mediocre yields. But the late-planted crop seems stunted in some areas, and lack of moisture could be limiting growth enough to affect canopy cover and yield potential. These problems are not beyond fixing in soybean fields, but at this point in the season what may be ideal conditions for the corn crop may be less than ideal for soybeans.


2014 Field Day August 7 at Dixon Springs Ag Center

The 2014 Dixon Springs Agronomy and Horticulture Field Day presented by the University of Illinois, Department of Crop Sciences will be held on Thursday, August 7 at the Dixon Springs Ag Center.  The research center is located on IL Route 145, near Glendale, IL, 25 miles south of Harrisburg and 25 miles north of Paducah, KY.

Tours will start at 9:00 AM with the final bus leaving at 9:30. A lunch to follow will be provided by sponsors and UI Extension.

The following presenters will speak about current conditions and management challenges in field crop and horticulture production.

  • Carl Bradley: Fungicide Resistance
  • Angie Peltier: Corn Nematodes, The Hidden Menace in Your Fields
  • Jake Vossenkemper: Nitrogen on Soybeans
  • Rachel Cook: Tillage is Recreational, Fertilizer is Essential: A 44 Year Study
  • Jeff Kindhart: High Tunnels, Hydroponics and Mushrooms

For more information contact John Pike at 618-695-2441 or by email at jpike@illinois.edu


Brownstown Agronomy Research Center Field Day – August 6

The 2014 Brownstown Agronomy Research Center Field Day, presented by the University Of Illinois Department Of Crop Sciences, will be held on Wednesday, August 6. Extension researchers and specialists will address issues pertinent to the current growing season. The tour will start at 8 a.m. and will last about two and a half hours. It will be followed by lunch provided by U of I Extension.

Shaded tour wagons will take participants to each stop. These topics will be addressed:

  • N Fertilizer for Soybean:  Where’s the Yield? – Jake Vossenkemper, U of I
  • Tillage is Recreational, Fertilizer is Essential – Dr. Rachel Cook, SIU
  • Field Crop Diseases & Fungicide Treatments – Dr. Carl Bradley, U of I
  • Corn Nematodes:  the Hidden Menace in Your Fields – Dr. Angie Peltier, U of I
  • Factors Contributing to a Healthy Soil – Troy Fehrenbacher, NRCS

The 208-acre Brownstown Agronomy Research Center has been conducting crop research on the claypan soils of southern Illinois since 1937. More than 30 research and demonstration projects are conducted at the Center every year. Visitors are always welcome.

The research center is located south of Brownstown on IL Route 185, approximately 4 miles east of the IL Route 40 / 185 junction.

For more information, contact Robert Bellm (618-427-3349); rcbellm@illinois.edu
Visit us on the web at http://web.extension.illinois.edu/barc/


Assessing the risk of white mold (Sclerotinia stem rot) of soybean in 2014

White mold of soybean (a.k.a. Sclerotinia stem rot), caused by the fungus Sclerotinia sclerotiorum, is a disease that can occur in the northern half of the state in cool, wet years.  The most recent, widespread white mold epidemic in Illinois occurred during the 2009 season, where several fields in the northern half of the state were affected.  In some of the northern-most areas of Illinois, white mold can be considered a more consistent problem.

The white mold fungus overwinters in the soil as, small, black, and dense structures known as sclerotia.  These sclerotia germinate and form mushroom-like structures known as apothecia when soil remains moist for several consecutive days and soil temperatures are at 60 degrees F or below.  These apothecia generally will not form until the soil is shaded from sunlight due to soybean canopy closure.  Spores of the white mold fungus are shot out of the apothecia and land on senescing flower petals, where infections first occur on the soybean plants.  The white mold fungus becomes inactive when temperatures within the soybean canopy are above approximately 82 degrees, so infection and disease development may cease or slow down during periods of hot (above 82 degrees) and dry weather.

Apothecia of the white mold fungus germinating from a sclerotium. Image courtesy J. Venette, North Dakota State University.

 

Soybean plant with symptoms and signs of white mold (a.k.a. Sclerotinia stem rot). Image by C. Bradley.

 

So, what does the risk of white mold look like for 2014?  This is not an easy question to answer.  In general, rainfall has been consistent in the northern portion of the state, which would favor white mold, but recent temperatures in the 80s and 90s have not been favorable.  However, the short-term weather forecast shows cooler temperatures (60s and 70s).  If a cool and wet trend continues throughout soybean flowering, then the risk of white mold will be elevated.

In University of Illinois research trials, some fungicide products have shown efficacy against white mold.  Foliar fungicides will not provide complete control of the disease, but may reduce disease.  The results of University of Illinois trials conducted in 2009, 2010, and 2013 are shown in Tables 1-3.  Note that some of the more popular, frequently marketed fungicides are not listed in the tables since many do not have white mold on their label because of no to poor efficacy.  In these trials, the primary targeted growth stage to apply foliar fungicides was at R1 (beginning flower).  In some cases, R1 may occur before canopy closure.  If this is the case, then an application at canopy closure (rather than R1) might be more effective in protecting against white mold.  Also note that some treatments in these research trials were applied twice during the season.

 

Table 1. Results of soybean foliar fungicide research trials focused on white mold conducted in 2009 at the University of Illinois Northern Agronomy Research Center (DeKalb County).

Treatment Rate/A Incidence (%) 

8-11-09

Incidence (%) 

9-14-09

Yield (bu/A)
Untreated check 75 95 24
Topsin 4.5 L 20 fl oz 43 96 24
Proline 3 fl oz 38 95 24
Domark 5 fl oz 68 98 23
Cobra herbicide 12.5 fl oz 15 51 42
Omega 1 pt 23 80 34
Endura (2x)* 8 oz 38 86 39
Aproach (2x)* 8 fl oz 35 80 40
LSD 0.05** 33 15 8

*All treatments were applied at the R1 growth stage (July 20, 2009).  Treatments followed by “(2x)” were applied again 9 days later.

**Least significant difference (alpha level = 0.05).  Treatment values that differ by this number can be considered significantly differ from one another.

 

Table 2. Results of soybean foliar fungicide research trials focused on white mold conducted in 2010 at the University of Illinois Northern Agronomy Research Center (DeKalb County).  Funded in part by the Illinois Soybean Association.

Treatment Rate/A Incidence (%) 

8-11-09

Incidence (%) 

9-14-09

Yield (bu/A)
Untreated check 18 95 62
Topsin 4.5 L 20 fl oz 9 83 61
Proline 3 fl oz 10 89 66
Domark 5 fl oz 7 76 63
Cobra herbicide 6 fl oz 6 86 56
Omega 1 pt 2 70 58
Endura 8 oz 4 79 69
Aproach (2x)* 8 fl oz 11 79 66
LSD 0.05** 11 NS 8

*All treatments were applied at the R1 growth stage (July 10, 2010).  Treatments followed by “(2x)” were applied again 7 days later.

**Least significant difference (alpha level = 0.05).  Treatment values that differ by this number can be considered significantly differ from one another.  “NS” indicates that no treatments were significantly different from each other.

 

Table 3. Results of soybean foliar fungicide research trials focused on white mold conducted in 2013 at the University of Illinois Northern Agronomy Research Center (DeKalb County). Treatments were applied at the R1 growth stage unless indicated otherwise.

Treatment Rate/A Incidence (%) 

9-19-13

Yield (bu/A)
Untreated check 33 53
Incognito 4.5F 20 fl oz 20 68
Incognito 4.5F + Orius 3.6F* 20 fl oz + 4 fl oz 0 62
Proline + Stratego YLD** 3 fl oz + 4.65 fl oz 3 58
Domark 5 fl oz 3 62
Cobra herbicide 6 fl oz 25 52
Endura 8 oz 3 64
Aproach 8 fl oz 13 61
Fortix 5 fl oz 15 56
LSD 0.05*** 22 7

*Incognito was applied alone at the R1 growth stage and was followed by Orius applied alone at R3.

**Proline was applied alone at the R1 growth stage, and was followed by Stratego YLD applied alone at R3.

***Least significant difference (alpha level = 0.05).  Treatment values that differ by this number can be considered significantly differ from one another.  “NS” indicates that no treatments were significantly different from each other.

Overall, the highest level of white mold control will be achieved when several management practices are integrated (i.e. choosing the most-resistant varieties, utilizing recommended seeding rates, applying a foliar fungicide, and applying a biocontrol product).  For more information about white mold and management of this disease, go to http://www.soybeanresearchinfo.com/pdf_docs/WhiteMold_NCSRP.pdf, where a 7-page publication on white mold (developed in 2011) can be downloaded.


July 15th Field Day at University of Illinois’ Research Center in Monmouth

The program is set for the 33rd annual University of Illinois’ Northwestern Agricultural Research Center Field Day. The program will begin at 8 am on Tuesday, July 15th.

Buses will carry members of the public to different stops in the research center where campus-based specialists or Extension personnel will present the results of crop and pest management research and current recommendations.

Topics and speakers will include:

  • Stewardship of dicamba and 2,4-D resistant soybean Mark Bernards—Assistant Professor of Agronomy, Crop Science, and Weed Control, Western Illinois University
  • On-Going Concerns Regarding Corn Rootworm Resistance to Bt Hybrids—Mike Gray— Extension Entomology Specialist, University of Illinois
  • Palmer Amaranth: Coming (Soon) to a Field Near You—Robert Bellm—Extension Educator, Commercial Agriculture, University of Illinois
  • Do Soybeans Need Fertilizer N? —Emerson Nafziger—Extension Crop Production Specialist, University of Illinois
  • Unmanned Aerial Vehicles: Sky High Scouting—Dennis Bowman—Extension Educator, Commercial Agriculture, University of Illinois

The Northwestern Illinois Agricultural Research and Demonstration Center is a 320 acre facility, established in 1980, 1 mile North and 4 miles West of Monmouth at 321 210th Avenue. Each year, more than 50 different projects are conducted by up to 12 campus-based project leaders and the center superintendent.

For more information about continuing education units to be offered visit the Hill and Furrow Blog or the Northwestern Illinois Agricultural Research and Demonstration Center website.

If you need a reasonable accommodation to participate in this program, please contact Angie Peltier (309) 734-5161, apeltier@illinois.edu.


Call for Grain Samples

There is some evidence that the “book values” that we have used for many years to calculate the amount of P and K removed by grain during harvest may no longer be accurate for the crops we produce today. The economic and environmental advantages of matching crop removal to replacement with fertilizer nutrients makes it important to have good removal numbers.

With funding from the Nutrient Research & Education Council (NREC) we are starting a new project in 2014 to try to get a better idea for how much nitrogen (N), phosphorus (P), and potassium (K) are contained in harvested grain of corn, soybean, and wheat. This seems like a simple thing to measure, but we expect that things like yield level, soil, crop variety, and growing season weather affect may nutrient levels. Thus we will need to sample widely in order to get a handle on removal.

We hope to get most of the grain samples we need to do this from individual producers across Illinois, with samples sent right out of the field or when grain is stored or delivered to the elevator. We’re starting now in hopes of kicking this off with wheat samples.

We will make it as painless as possible to send in samples, following the procedure below:

1. Before harvest or at the time grain is stored or moved, the cooperating producer will send an email to NPKremoval@gmail.com to request a mailer. The email only needs the cooperator’s name, mailing address, and what grain (wheat, corn, or soybean) is being sent in. If the mailing address is in a different county than the field the sample comes from, please indicate what county the sample will be from.

2. Prepaid mailers will be sent to the cooperator. The mailer will include a plastic sample bag with a label that has the cooperator’s name and crop, and will have only a blank to fill in with the yield level (estimated or measured) of the field from which the sample came (or will come.)

3. The sample bag is sized to hold about 6-8 oz. of grain, which is all we need. The grain should be dry (at or below standard moisture) so it keeps well during shipping. Simply put the bag with grain into the mailer and drop it into the US mail. It will be addressed to go to a lab for analysis.

While we are hoping for a lot of cooperators, sample numbers will be limited by the funds available. That may mean limiting samples from an area where a lot of people volunteer to send samples. If a local elevator would like to send samples from trucks coming to unload, that would work, but would mean recording names, addresses, and yield levels at the point of collection. We would appreciate having seed company or other ag retail personnel encourage individual producers to take part.

Results will be summarized by region, with no identification of individual cooperators. We hope to collect samples over 2014 and 2015, and hope by getting a large number of samples to be able to see how much variability there is in removal numbers and to generate better removal numbers for Illinois producers.

Please email me if you have any questions about this.


Wheat scab rearing its ugly “head” again in 2014

Head scab of wheat (a.k.a. Fusarium head blight) is showing up in the southern portion of Illinois.  In many cases, incidence is moderate to high (over 50% of the heads affected).  Affected wheat heads will appear “bleached” in color.  Heads often are partially affected, with both healthy green and affected bleached areas being present in the same head.  Although I have not been in all wheat production areas in the state, my general observations are that fields in southern Illinois (south of Interstate 70) range from a moderate to high incidence of scab.  The differences in scab incidence from field to field likely are due to differences in susceptibility of the varieties planted, application or no application of fungicides, and local weather.

Wheat field affected by head scab (Fusarium head blight). Note the "bleached" heads. (Photo by Carl Bradley)

Wheat growers may want to evaluate the level of scab in their fields.  It is easiest to observe this disease before heads completely mature.  Growers with moderate to high levels of scab should consider making adjustments to their combine that would allow low test-weight, scabby kernels to be blown out the back of the combine.  Recent research conducted at the Ohio State University indicated that adjusting the combine’s fan speed between 1,375 and 1,475 rpms and shutter opening to 90 mm (3.5 inches) resulted in the lowest discounts that would have been received at the elevator due to low test weight, % damaged kernels, and level of the mycotoxin deoxynivalenol (DON; vomitoxin) present in the harvested grain (Salgado et al., 2011).

 

Wheat head affected by scab (Fusarium head blight). (Photo by Carl Bradley)

Reference:

Salgado, J. D., Wallhead, M., Madden, L. V., and Paul, P. A. 2011. Grain harvesting strategies to minimize grain quality losses due to Fusarium head blight in wheat. Plant Disease 95:1448-1457.