Blog Archives
What do Mycotoxin Levels Mean?
Last week I was receiving text messages from a few of our farmers about corn harvest results from damaged corn. Low levels of mycotoxins are being detected in samples thus far, thankfully.
A reminder, the presence of mold does not automatically mean a mycotoxin is present. The fungi producing mold have the potential to produce mycotoxins.
Here’s What the Numbers Mean…
For aflatoxin, the U.S. Food and Drug Administration has set a recommended limit of 20ppb (parts per billion) for dairy animals, 100 ppb for breeding animals, and 300 ppb for finishing animals. To put this is simpler terms, a sample would need 20 affected kernels out of a billion kernels to be at the legal limit for dairy animals. So far, most samples are coming up at 5-6ppb which is very low.
For fumonisin, 20ppm (parts per million) is the recommended limit set by FDA for swine, 30ppm for breeding animals, 60ppm for livestock for slaughter, and 100ppm for poultry for slaughter. So, this would mean 20 affected kernels in a million kernels could cause a problem for swine. Again, our levels are averaging closer to 5ppm right now which are low.
Deoxynivalenol (DON) also known as vomitoxin is another mycotoxin being tested from grain samples. This mycotoxin causes reduced weight gain and suppresses animal feeding, especially in swine. Concentrations greater than 10ppm can result in livestock vomiting and totally refusing feed. FDA has recommended that total feed levels of DON not exceed 5 ppm for cattle and chicken, and 1 ppm for swine.
It is very important to sample from several places in the grain to get an accurate sample for damage and mycotoxins. It is also very important that black light tests are not used to determine the presence or absence of mycotoxins. Some of these mold fungi produce a compound that fluoresces under black light, but research has shown that this quality does not consistently predict the presence of mycotoxins (often provides false positives). Finally, before any of your storm-damaged corn is put in a bin, call your insurance agent out to get a sample!
Protecting Your Health with a Mask
There is some great information from the University of Nebraska Med Center on what types of masks to use to protect your health from molds and potential mycotoxins. Some people tend to have more sensitive immune and respiratory systems than others, so I’d highly recommend checking out these short videos.
Sprouting Corn Kernels on Hail-Damaged Ears
The latest event in the Clay County storm occurring August 1st has become germination of “good” kernels left on the ears that have been damaged by
hail. This event of kernel germination prior to harvest is also called “vivipary”.
Typically we wouldn’t see this occur before black layer because of the hormonal balance within the kernels-particularly the balance between gibberellin and abscisic acid. According to a study by White, et. al (2000), Gibberellin production with the lack of ABA allowed for kernel germination while less Gibberellin and more ABA deterred kernel germination. At full maturity, very little ABA is left in the kernel (in both corn and soybeans) which allows them to germinate in correct conditions after harvest. But this can also allow for sprouting in the ear after black layer when corn is still drying down, particularly in tight-husked, upright ears with conditions of high humidity or rain after black layer. Sprouting under those conditions typically occurs at the base of the ear first.
Why are kernels sprouting before we’ve reached black layer?
That’s a good question. I haven’t found much in the way of scientific explanation other than the thought that the hormonal balance of the kernels can be altered by physical damage from hail, bird feeding, and grain mold. Some ear mold fungi also produce gibberellic acid which can lead to a hormonal balance shift in these ears stimulating germination. I also haven’t observed that this is hybrid-dependent and am finding as much as 25-50% sprouted ears in various areas of hail-damaged fields.
What can you do now?
Make sure your crop insurance adjuster is aware of the situation and make sure to submit samples for kernel damage due to mold, sprouting, and check for mycotoxins prior to harvest.
The local co-op may or may not choose to accept the load depending on percent damage and the standards they need to follow. If the load is rejected, contact your crop insurance agent to determine your next step. DO NOT bin the grain on your farm until you contact your insurance agent as they have specific rules that need to be followed in the case of grain rejected due to mycotoxins or kernel damage from storms.
Sprouted kernels lead to higher kernel damage and more fines in a load. Keys for harvest will include harvesting early, getting corn dried down to 14%, potentially drying at a high temperature to kill the sprout, screening out fines, and monitoring stored grain closely for hot spots, mold, and additional sprouting grain.
You can also choose not to take it to grain right now, and honestly, that may be the best option for several of the hail-damaged fields. Silage is still an option and it would be recommended to sample the green chop going into the silage pit for potential mycotoxins. Mycotoxin level does not change with fermentation so cattle feeders would have a good idea of any mycotoxin levels if sampling was done in this manner. See this post for additional information on making silage.
Additional information:
Du-Pont Pioneer. (2007). Field Facts: Pre-mature Germination of Corn Kernels.
Nielsen, R.L. (2012). Premature Corn Kernel Sprouting (aka Vivipary). Corny News Network, Purdue University.
White et. al. (2000). Gibberellins and Seed Development in Maize. II. Gibberellin Synthesis Inhibition Enhances Abscisic Acid Signaling in Cultured Embryos. Plant Physiology Vol. 122 no. 4 pg. 1089-1098.
Wiebold, B. (2009). Wet Weather Can Cause Seeds to Sprout before Harvest. Integrated Pest & Crop Management Newsletter, Univ of Missouri.
Extent of Storm Damage Visual
This map came from Kansas State University in a newsletter where they were talking about the vegetation differences from the Drought of 2012 to 2013 in Kansas. A colleague shared this with me pointing out how obvious the storm in Clay County, NE is on this map. Look above Kansas to the brown area-that’s the LOSS of vegetation we have right now in Clay County which is quite extensive-and neat how it’s captured unexpectedly on this map.
Rural Futures Conference
Do you have a passion for building strong and resilient rural communities? Do you think about the future and what is in store
for rural people and places? If so, I’d encourage you to plan on November 3-5, 2013 at The Cornhusker, A Marriott Hotel in Lincoln, Nebraska for the 2013 Rural Futures Conference and participate in the dialogues around these very issues.
The theme for the 2013 Rural Futures Conference is Beyond Boundaries, which encourages all of us to step beyond our typical boundaries and work together to create positive rural futures. While moving beyond boundaries can be challenging and even ominous, it also provides the unique opportunity to implement a foundation of collaboration that can impact the future of rural people and places. The upcoming conference will celebrate the importance of rural and create energy and enthusiasm for new and innovative ways to address complex opportunities and challenges. From University faculty, staff and students to community citizens and organizational partners, don’t miss the opportunity to transcend boundaries and collaboratively make a difference.
One of the greatest resources in any organization or community is its people. When we think about rural places, there is no doubt that the people and leadership in rural America is a driving force for progress. There are several opportunities for you to be involved in and even contribute content to the 2013 Rural Futures Conference. We encourage you to share your knowledge and expertise at the conference to help us explore new ideas, discover synergies, and facilitate partnerships. Please consider being involved in one or more of these opportunities during the conference, and encourage others to become involved as well.
Quick Pitch Spotlight: Conference participants rapid fire their “big idea” for rural people and places.
Community Questions: Communities of place or interest pose questions that stimulate collaboration and potential research opportunities.
Faculty and Partner Poster Session: Participants display current work or research relevant to the rural futures.
Registration opens September 1, and will remain open until the seats are filled. Registration closed early last year because maximum capacity was reached, so register early to ensure your spot. For more information or to register, visit ruralfutures.nebraska.edu/conference.
For the latest information on the 2103 Rural Futures Conference, follow Rural Futures on Twitter at twitter.com/rural_futures (hashtag: #RFC2013) or Facebook at facebook.com/ruralfutures
Apps and Mobile Sites for Mobile Devices on the Farm
It didn’t take long for the phrase “there’s an app for that” to be seen and heard regularly in the phone and mobile device
world. Today, there are many apps and mobile websites that can be fantastic tools for producers to use in decision-making. University of Nebraska Extension has developed several mobile apps to take a look at and be sure to visit our site often to learn of additional new apps.
In addition to our Extension Apps, Dennis Kahl, UNL Extension Educator, and I have also compiled a list of a few mobile apps that we think could be useful to farmers yet this year as they get closer to harvest, but also for next year to test out and see if they will indeed help them do work quicker and make decisions more accurately.
Today we are going to highlight a few mobile applications and mobile websites that producers may be using now as they make preparations for fall harvest.
- UNL CropWater – provides an easy way to estimate soil water status based on Watermark sensors installed at depths of 1, 2, and 3 feet. With these sensor readings, the Crop Water app will estimate the water used as well as what is still available for Nebraska soils.
- Market Journal – Television for Ag Business Decisions. Weekly crop reports, markets, weather and current insect,
disease and harvest issues. It was also listed at Agriculture.com’s #1 ag app for 2013. - RealAgriculture – focuses on the issues that are impacting agriculture. The site is focused on getting farmers the opinions on issues so that you not only get the news but the insight into what the news means in the production business.
- DTN/PF – The Progressive Farmer – provides market data, link charts to market data for single, seamless view of how the latest prices correlate with current market trends.
- Farm Progress – Keep up on local ag news, grain and livestock markets, enhanced weather and blogs as well as Nebraska Farmer magazine.
- Husker Harvest Days Show – Maximize your time at Husker Harvest Days with this application that includes exhibitor and category lists, show maps and other tools to help you maximize your time at the show.
- Ag PhD Harvest Loss Calculator – Allows farmers to estimate yield loss before and during harvest by recording the number of individual corn, soybean, wheat, sorghum, barley or oat seeds found on the ground in a square foot.
- Combine Performance Optimizer by John Deere – Help operators adjust and set the critical settings for next year’s harvest of small and large grain crops to improve machine performance.
- Calibrate My Sprayer – Aid in the proper calibration of spraying equipment.
- In addition to the apps listed above, Crop Life featured a story of the Top 13 Mobile Ag Apps for 2013 and Agriculture.com has a list of mobile apps. Take a look at these as well.
With wireless technology available in most areas of the state, we utilize Verizon Wireless with our mobile devices in the field and in our communities to update various social media outlets such as Twitter, Facebook and blogs. Mobile access has allowed University of Nebraska Lincoln Extension to provide current information and situations in the field at all times. We encourage producers to subscribe to various resources including:
- Twitter
- @UNL_Cropwatch
- @UNLBeef
- @MarketJournal
- @IANRNewsService
- @UNLExtension
- For information on some of the newest technology, visit Innovative Tips for Rural Communities blog.
- If you are interested in staying up-to-date with crop information be sure to subscribe to and bookmark cropwatch.unl.edu and subscribe to Jenreesources Extension Blog.
Special thanks to Dennis Kahl as a Guest blog contributor to this post!
Forage Options After the Storm
Thank you to everyone who participated in the Town Hall Discussion on such short notice last week! It was cool watching
everyone come together to discuss the concerns at hand. Here’s a recap of some of the discussion regarding forage options. We also have provided numerous articles this week and will again next week at UNL’s CropWatch website. I will continue to post more about our local conditions on my blog.
Forage Options
Dr. Bruce Anderson explained that the best potential usage of storm damaged corn that won’t go for grain is to use it for silage. He stressed that the silage has to be made at the correct moisture and packed well-and that standing corn could be over 80% moisture right now. He mentioned the easiest and maybe the best way to lower moisture content is to simply wait until some stalks start to turn brown. This will also allow the surviving corn to continue to add tonnage. If waiting isn’t desirable, reduce moisture by windowing the crop and allow it to wilt one-half to one full day before chopping. You also could mix grain or chopped hay with freshly chopped corn to lower the moisture content. It takes quite a bit of material for mixing though — about 7 bushels of grain or 350 pounds of hay to lower each ton of silage from 80% to 70% moisture. When making silage, he recommended adding the inoculant during the chopping process to allow for proper fermentation.
He mentioned haying and baling were an option but that he was concerned about the amount of time it would take for the stalks to dry down at the current moisture. He recommended crimping the stalks if at all possible to help aid in the drying process. Be sure to test it for nitrates before feeding.
Grazing might be the easiest way to use damaged corn, and this is a good way to extend your grazing season. You might even plant some corn grain or sorghum-sudangrass or oats and turnips between rows to grow more forage for grazing if you can wait until late fall before grazing. Be sure to introduce livestock slowly to this new forage by feeding them before turning them in to reduce the chances of digestive problems. Also, strip graze the field to reduce trampling losses and get more grazing.
Shredding was mentioned as an option in some fields. Dr. Bob Klein observed two years ago in the wind storm out in western Nebraska that shredding of plant material led to piles after wind drifted loose material in the field. That made for a difficult planting situation the following year. Making earlage was also mentioned as an option.
Additional Resources:
- Forage Options with Damaged Corn
- Planting Cover Crops Into Storm Damaged Fields
- Tips for Planting Fall Forages and Other Salvage Uses
- Flying Turnips or Rye into Corn or Soybeans
- Making Silage? Protect Your Investment for the Long Term
- Great deal of information regarding forage options (mostly related to drought), but good info. to sift through at: http://droughtresources.unl.edu/corn
Storm Damaged Crops
The rain was welcome on Thursday but the wind and hail damage that came were devastating to a good portion of the
County. I’m so sorry to all of you affected….for some of you, this is two years in a row of severely hail damaged or totaled out crops. We are thankful the damage wasn’t worse. You can see more pictures here.
So the big question is what do you do now? Ultimately, each field will need to be assessed on a case by case basis. The following are our NebGuides for hail damage to corn and soybeans. For the most part we were in brown-silk to blister for corn and late pod-beginning seed in soybean (R4-R5). The concerns I have right now are stalk quality, disease, grain filling, and the amount of diseased grain we may have due to mushy areas on hail-damaged cobs right now. Several years ago, we watched how severely hail-damaged corn a little later in the season turned brown and died. We also know that southern
rust is in the area and while much of the leaf tissue in the County is damaged, it is still in the County in other fields and south of us. The Puccinia polysora fungus that causes southern rust, when severe enough, will infect and cause pustules on the stalks. With the wounding and low leaf area for photosynthesis, stalk strength is a concern and fungicides may be a consideration depending on potential yield loss-again need to assess on a field by field basis.
I talked with a number of people on Friday regarding thoughts on silage, green chop, haying/baling, planting cover crops, etc. Dr. Bruce Anderson, UNL Extension Forage Specialist, said the most common salvage operation for corn damaged by hail, wind, drought, or other calamities is to chop it for silage. Don’t be in a hurry, though. Standing corn currently could be over 80 percent moisture. The easiest way, and maybe the best way, to lower moisture content is simply wait until some stalks start to turn brown. Waiting also allows surviving corn to continue to add tonnage.
But in some of our damaged fields, I don’t think we can wait to make silage. Bruce also shared you can reduce moisture by windowing the crop and allow it to wilt one-half to one full day before chopping. You also could mix grain or chopped hay to freshly chopped corn to lower the moisture content. It takes quite a bit of material for mixing though – about 7 bushels of grain or 350 pounds of hay to lower each ton of silage down to 70 percent moisture from an original 80 percent moisture. That’s 7 bushels grain or 350 pounds of hay for each ton of silage.
Or, you can allow that windrowed corn to dry completely and bale it as hay. Be sure to test it for nitrates before feeding. Grazing might be the easiest way to use damaged corn, and this is a good way to extend your grazing season. You might even plant some corn grain or sorghum-sudangrass or oats and turnips between rows to grow more forage for grazing if you can wait until late fall before grazing. Be sure to introduce livestock slowly to this new forage by feeding them before turning in to reduce the chances of digestive problems. Also, strip graze the field to reduce trampling losses and get more grazing from the corn.
Southern Rust
Several of us had been watching the USDA IPM Pipe Map for weeks. It wasn’t showing southern rust moving and only Georgia
was really lit up. Yet, I had heard reports in Texas and Oklahoma at one point. Spots were evident on corn leaves when backlit-so they were bound to develop into something.
That something has showed itself to be southern rust last week as it was confirmed in 11 Nebraska Counties: Kearney, Adams, Clay, Nuckolls, Thayer, Fillmore, Gage, Platte, Polk, York, and Boone. I’d like to thank all the crop consultants and ag industry professionals for sharing information on what we all were seeing and for submitting samples. 
So the common question was, why didn’t the map show anything south of us? Federal funding was no longer available for this site and scouting efforts associated with it. Many Extension Plant Pathologists weren’t aware that the site was even still online and were sharing information via other means instead. The map for Nebraska will continue to be updated, but for surrounding states, it is advised to consult with your local Extension Plant Pathologist.
Differentiating Rusts:
When differentiating between southern rust vs. common rust, there are several criteria to consider and this NebGuide is a great resource. Typically common rust will have brick-red pustules randomly scattered on the upper and lower leaf surfaces that are larger in size.
For southern rust, we’re seeing very small, raised, tan-orange pustules on the upper leaf surface of leaves in localized areas on mid-upper leaves. These pustules are tightly clustered on the leaves. 
However, color and size are relative as sometimes the two diseases can look alike.
Microscopic observation is the best way to differentiate the two diseases. Fungal spores from Puccinia sorghi causing common rust will be near perfect round circles whereas fungal spores from Puccinia polysora will be oblong in shape.
Disease Progression:
With the cooler weather last week, we were unsure how the disease would progress. Southern rust likes sustained temperatures in the 80’s-90’sF with humidity and leaf wetness. So we encourage scouting for it.
We saw how southern rust can be devastating to fields in the past regarding removing photosynthetic tissue leading to cannabalization of the stalk. In determining a fungicide application, consider 
disease pressure in your field, stage of growth, pre-harvest intervals, and length of time for fungicide residual in addition to economics.
Look-A-likes:
Other plant samples brought in contained diseases such as physoderma brown spot (which isn’t a significant yield limiting disease of corn). Because the spores of this fungus move via water (it’s closely related to oomycetes), numerous lesions can appear on leaves in bands or areas where water collects. While the lesions may look like early southern rust, there will be no pustules present and often the purple colored lesions will also be observed in the midrib, leaf sheath, stalk, and outer husks.
- More information can be found in this article from UNL Extension’s CropWatch.
Goss’ Wilt in Corn
Goss’ wilt was found this week in corn damaged from Memorial Day storms in Clay County. I’ve also received pictures that appeared to
be Goss’ from crop consultants in other areas of the State. Goss’ wilt lesions have a wavy edge, have a varnished look to them when wet, and have characteristic black “freckles” within and particularly along the lesion edges. We are seeing some plant death due to the systemic version of Goss’ wilt. This can be seen by taking a cross-section of the stem and looking for orange discoloration in the vascular bundles. Because this is a bacterial disease, fungicides are not effective in controlling Goss’ wilt. If you are interested in trying a product that is labeled for treating bacterial diseases in corn, we would recommend you test its effectiveness via on-farm research. Spraying in a paired comparison treatment design will give you a true answer if the product made a difference for you or not.
To do this simply:
1-Spray a pass or round with the product (depending on sprayer size) to ensure you can harvest two passes from the center of the treated area.
2-Skip the same amount of distance as you previously sprayed.
Repeat steps 1-2 at least three more times
Mark a few plants in each plot and take photos throughout the growing season to determine if disease progresses or not. You may also wish to keep track of percent of plants affected in each untreated and treated area throughout the season, and check for percent stalk rot and harvest population in each area before harvest as well.
Make sure to harvest two passes from the center of each treated and untreated 
area. Then compare the weights as shown in the harvest figure. Please let Jenny Rees jrees2@unl.edu (402) 762-3644 know if you decide to conduct this study and if you have any questions!
More information:
Goss’s Wilt from UNL
Sample Submission to UNL Plant and Pest Diagnostic Clinic
Nebraska On-Farm Research Network
JenResources 