Category Archives: Grain Storage
Harvest Grain Quality Concerns 2026
I’ve been thinking of the grain quality concerns and safety with the upcoming harvest. We all know how crazy it’s soon to get with harvest. Unfortunately, most of the corn and soybean are ready now at the same time. It’s hard to know how to prioritize harvest. Normally, we’d go by percent stalk rot in a field of corn and percent moisture in both corn and soybean. Perhaps there’s still ways to prioritize based on those factors, but now we have the additional concern of looking at grain quality as well in both crops. The following article has tips as one faces harvest these coming weeks: https://cropwatch.unl.edu/harvest-2025-prep-guide-minimize-losses-disease-stressed-corn/.
For stalk rot assessments: Push at least 100 corn plants to arm’s length about 30 degrees from vertical. If plants bend below the ear and don’t snap back upright, they have a greater chance of lodging at or prior to harvest if there’s high wind events or heavy rain. I prefer the pinch test in which one squeezes the lower internodes to assess stalk strength and check for stalks that are easily crushed by hand.
Both corn and soybean have sprouting occurring in the field. In corn, this is particularly occurring where ears are upright with tight husks. With soybean, it’s occurring where the beans in the pods dried down to 13% or less and rewetted to at least 50% of their seed weight with the rains. There’s also a number of fungal kernel rots occurring in corn. Fusarium and giberella have a white/pink/red fungal growth. The presence of the fungus doesn’t guarantee mycotoxins are present, but potential mycotoxins that can be associated with these fungi are vomitoxin and fumonisin. White fungal growth that overtakes an ear and makes it feel very light is diplodia. There are no mycotoxins associated with it. There’s also a number of “lesser fungi” that cause cob rots that we’re also seeing this season.
It’s important to know what’s impacting the corn ears prior to harvest, binning corn, or taking it to the elevator. If a particular hybrid is more impacted by kernel rot than another, make sure not to put that corn in the same bin as corn with better quality. Grain affected by ear rot diseases and mold are less suitable for storage. Use or sell affected grain first and store the highest quality corn possible. Grain needs to be cooled to 55F and at 13-14% moisture in order to stop Fusarium and other fungi from continuing to grow in the bin. More info. at this resource: https://cropprotectionnetwork.org/publications/storing-mycotoxin-affected-grain
For soybeans, it’s also important to know if the variety in the field is impacted by things like purple seed stain or Phomopsis seed decay, which can cause elevators to reject soybeans. If you’re noticing discolored soybeans, talk to the elevator beforehand. Both of these conditions are variety related so keep track of which varieties you observe these conditions in.
Set combine fans to blow out as many broken/damaged kernels from insects, fungi, or sprouting as possible. Adjust combine settings to reduce harvest losses due to brittle kernels. Aim to start harvesting fields at a higher moisture (above 17%).
It will be a dirty harvest as secondary fungi can turn the leaves and stalks a blackish color. Fungal spores may behave like dust and aggravate respiratory illness or symptoms in sensitive individuals. Consider wearing dust masks or respirators when working in affected fields or around grain, such as in grain bins. Check air filters on equipment operating in conditions with a lot of dust and spores. Keep fire extinguishers close at hand. Take breaks as needed — and care for your mental, emotional and physical well-being. Be careful on roads: use headlights especially on gravel roads and check intersections before proceeding through them in the country. The Nebraska Rural Response Hotline is 800-464-0258 and is available for emotional support, legal and financial assistance, and disaster relief. Wishing everyone a safe harvest and hoping yields aren’t impacted too much from the challenges.
Corn Observations
Grain Storage
There’s over 25 species of fungi that can produce ear molds with the majority of them ceasing growth at 14% moisture within the kernel. For short term storage of moldy grain, drying to 15% moisture as quickly as possible can greatly slow additional fungal growth within the grain bin. The table below shares the days required to dry corn to 15% moisture with 1.0 cfm/bu and various temperature and humidity conditions. More info. at this resource: https://cropprotectionnetwork.org/publications/storing-mycotoxin-affected-grain
“Since drying time is directly proportional to the airflow, the producer can calculate the estimated drying times when using airflows other than 1.0 cubic foot of air per minute per bushel (cfm/bu). For example: Table II shows when drying corn from 18 percent to 15 percent moisture with 50F and 50% relative humidity air, the estimated drying time is 12.5 days using a 1.0 cfm/bu airflow. If the airflow is 1.25 cfm/bu, the estimated drying time would be 12.5 days / 1.25 = 10 days. For 1.5 cfm/bu, the drying time would be 12.5 days / 1.5 = 8.3 days. For 0.8 cfm/bu, the drying time would be 12.5 days / 0.8 = 15.6 days.” Source: Management of in-bin natural air grain drying systems to minimize energy cost.
- Management of in-bin natural air grain drying systems to minimize energy cost
- UNL CropWatch Grain Storage Resources
- Managing large grain bins for potential mycotoxin contamination
Mycotoxin Information
In 2026, we’re primarily seeing Fusarium and Gibberella species which have the potential to produce mycotoxins. Thus, the information below is directed at those fungal species and mycotoxin levels that can be associated with them. Again, the presence of fungi does not automatically mean a mycotoxin is present.
The following toxins can be produced from species of Fusarium and Gibberella. Source: Corn Ear Rots, Storage Molds, Mycotoxins, and Animal Health, Iowa State publication, 1997.
Source: Corn Ear Rots, Storage Molds, Mycotoxins, and Animal Health, Iowa State publication, 1997.
JenREES 4-5-20
Youth/Family Support: Last week I shared this link for many hands-on learning activities: https://4h.unl.edu/virtual-home-learning. Two more resources that may be helpful for families right now: Helping Children Cope with stress and change: https://child.unl.edu/helping-children-cope and Reading for Resilience which helps children cope with storybooks: https://child.unl.edu/read4resilience.
Checking grain bins: A local farmer suggested to share a reminder to keep checking on grain with temps warming up and much grain in storage. It’s also so important to be safe with grain handling. The following is from Dr. Ken Hellevang with North Dakota State University (full article at: https://www.ag.ndsu.edu/news/newsreleases/2020/march-23-2020/proper-spring-grain-drying-and-storage-critical). “The stored grain temperature increases in the spring not only due to an increase in outdoor temperatures but also due to solar heat gain on the bin. Solar energy produces more than twice as much heat gain on the south wall of a bin in spring as it does during the summer.
Hellevang recommends periodically running aeration fans to keep the grain temperature near or below 30 degrees until the grain is dried if it exceeds recommended storage moisture contents, and below 40 degrees as long as possible during spring and early summer if the grain is dry. Night air temperatures are near or below 30 degrees in April and 40 degrees in May. Soybean oil quality may be affected in less than four months if even 12% moisture soybeans are stored at 70 degrees.
Cover the fan when it is not operating to prevent warm air from blowing into the bin and heating the stored grain. Hellevang also recommends ventilating the top of the bin to remove the solar heat gain that warms the grain. Provide air inlets near the eaves and exhausts near the peak or use a roof exhaust fan… Grain temperature should be checked every two weeks during the spring and summer. Grain also should be examined for insect infestations. Check the moisture content of stored grain to determine if it needs to be dried. Remember to verify that the moisture content measured by the meter has been adjusted for grain temperature.
Corn needs to be dried to 13% to 14% moisture for summer storage to prevent spoilage. Soybeans should be dried to 11% to 12%, wheat to 13%. The allowable storage time for 13% moisture soybeans is less than 100 days at 70 degrees. Corn – For natural air-drying, assure that the fan’s airflow rate is at least 1 cubic foot per minute per bushel (cfm/bu) and the initial corn moisture does not exceed 21%. Start the fan when the outdoor temperature averages about 40 degrees. Soybeans – Use an airflow rate of at least 1 cfm/bu to natural air-dry up to 15% to 16% moisture soybeans. Start the fan when the outdoor temperature averages about 40 degrees.”
Burndown and pre-plant herbicide apps: Anticipating this week’s nicer weather, I’ve also received several questions on burndown and pre-plant herbicide applications and weather impacts on control. Dr. Amit Jhala wrote two articles in this week’s UNL CropWatch at https://cropwatch.unl.edu. Sunny days with temperatures above 40F for day and night, and even better when temps are climbing to the upper 50s and above provide better control than if it’s cooler than 40F. Glyphosate works faster during sunny conditions when it is 60-75F and remains there a few hours. The articles also list rain-fast period and planting interval restrictions (as would the product labels). If you’re looking for a general idea on potential residual activity of herbicides for overlapping residual, check out pages 23-24 of the 2020 Guide for Weed Management.
My colleague Dr. Nathan Mueller shared in his blog: http://croptechcafe.org/should-you-control-winter-annual-weeds-early/, “A 2007-2009 UNL study conducted in Lincoln and Clay Center found that in 5 of the 6 site-years (2 site per year for 3 years is 6 site-year) that not controlling winter annual weeds prior to corn and soybean planting resulted in greater than a 5% yield loss and a 10% loss in 4 of the 6 site years.”
Sharing some encouragement from my neighborhood to yours 🙂 Individuals within farm families could also write messages to each other!
JenREES 1-26-20
Corn Quality Concerns: The two main questions I’ve received: “Are you hearing others mentioning low/variable test weights on corn?” and “Are you hearing of loads being rejected (to ethanol plants) due to mycotoxins?” While I’m unsure how widespread this is, I have been receiving these questions. A reminder to check your grain quality if you haven’t already been hauling or checking it.
Test Weight is a volumetric measurement (weight of corn grain per unit of volume), and as such, doesn’t directly correlate with yield. Standard corn test weight is 56 lbs/bu (1 bushel is 1.24 cubic feet). The size, shape, slipperiness of surface, and density of the kernel impacts test weight. Hybrids can show differences in test weight. Test weight is different than kernel weight, and thus not directly correlated with yield. Test weight gets at how tightly packed the starch is within the kernel. Reducing kernel moisture can allow for increased test weight if the starch loses water allowing for it to be packed more tightly within that kernel. Dry kernels that slide past each other may pack better allowing for increased test weight.
Lower test weights can result with disease, insect, and environmental stresses that impact photosynthesis and the movement of nutrients to the kernel during grain fill. These can include foliar and stalk diseases, drought stress, lack of nutrients, freeze prior to physiological maturity, late planting, and below normal temps during grain fill. Rewetting of kernels in the ear can impact test weight as kernels can swell and not shrink back to the same shape as previously. We know that moisture events happened after physiological maturity causing some sprouting of kernels in some ears prior to harvest. We did have high foliar disease pressure this year and reduced stalk quality. Compromised integrity of the kernel due to insect, disease, and mechanical damage can also impact test weight. I didn’t see the amount of kernel damage as I did in 2018. But there are certain hybrids that are high yielding and widely planted that I tend to see starburst patterns on kernels (due to Fusarium) and shortened husks exposing ear tips to more insect damage/ear molds. There are also hybrids that had a large amount of top dieback, husk tissue that turned brown early, or refuge in a bag plants that died early in fields. All of these may be factors potentially impacting test weight as well. Thinking about photosynthesis, we had reduced solar radiation during grain fill. I can’t help but think that could also impact it but didn’t easily find research that correlates solar radiation to test weight. There’s research correlating solar radiation to yield and kernel weight, though.
Regarding vomitoxin levels, the starburst patterns on kernels, insect damage leading to
ear molds, wet corn not properly dried or cooled in bins can all impact greater Fusarium growth and the potential for vomitoxin to be produced. If vomitoxin (also called DON) is an issue, concentrations can triple in the ethanol process of producing the distiller’s grains. Hogs and poultry are more sensitive than cattle, so the end user may be a factor in addition to the vomitoxin levels. I don’t know the levels being rejected so I can’t speak more to this.
York County Corn Grower Tour: Corn growers and spouses are welcome to join us February 3 for a tour of ag industries in the Lincoln area. We will meet at the York Co. Extension Office at 7 a.m. and will carpool leaving at 7:15. Our first stop will be RealmFive which focuses on wireless connectivity for ag operations. We will then tour Smart Chicken in Waverly which offers retail- and foodservice-packaged organic chickens and antibiotic-free chickens from Kansas, Iowa and Nebraska. Lunch at Lazlos is next followed by learning about the UNL hops program and research using corn gluten meal and soybean meal. Possibly another stop on way home. Please RSVP to me at jrees2@unl.edu if you’re interested in attending by Feb. 2nd. Hope to have a good group who can join us! Flyer at jenreesources.com.
JenREES 3-24-19
This past week was tough at times yet also incredible to see people pull together, rally around each other, and donate so much. All of this is so hard to put into words…praying for those impacted and grateful for the many heart-warming stories amidst all the loss! I realize not everyone reading this is directly affected by the flooding. However, we all most likely know others affected and there’s several resources and information Nebraska Extension wishes to share. Please help us in sharing this information!
Flood Website: http://flood.unl.edu Information for Rural/Urban, Families, Business, Crop and Livestock Producers, Home Damage, and English/Spanish resources all in this one spot. Grateful for all my colleagues working really hard to redo/update this site! Also, all flood-related questions can be directed to: floodresponse@unl.edu
Volunteers: https://flood.unl.edu/how-can-i-help Individuals and organizations should never self-deploy. Support relief organizations that are already established in the area by contacting local organizations to see what support they need. You can also check with your county Emergency Manager. It’s also recommended to get a tetanus shot if you’re cleaning up in flood affected areas.
Homeowners: https://flood.unl.edu/cleaning-after-flood
- Get a tetanus shot before removing flood damaged items.
- Test private wells that may have come in contact with flood water before drinking or cooking. Kits can often be obtained from your local Health Department or Extension office. More info: https://flood.unl.edu/well-water
- First Steps for flood recovery: https://www.extension.purdue.edu/extmedia/ACS/ACS-101-W.pdf
- Cleaning up after a flood (includes videos and also questions to ask to ensure contractors are trustworthy). Remove drywall and carpeting as quickly as possible (24-48 hours) to prevent mold growth. Don’t rebuild until studs are 13% moisture: https://www.cdc.gov/disasters/cleanup/facts.html
- Free legal assistance for low-income flood survivors: https://flood.unl.edu/legal-aid
- Financial recovery and documentation: https://flood.unl.edu/family-financial
- Handling food following a flood: https://flood.unl.edu/foodsafety
Livestock: https://flood.unl.edu/livestock Our livestock producers care so greatly for their animals and work so hard to keep them safe and healthy. Prayers for all affected.
- Options for Disposal of Animal Carcasses including rendering and landfill locations, burial and composting considerations. EQIP assistance for disposal costs may be available; apply for waiver through local NRCS office before disposal: https://beef.unl.edu/beefwatch/options-disposal-animal-carcasses
- Contact local Farm Service Agency regarding losses. Phone call starts the process and only have 30 days to report for Livestock Indemnity Program. Can report losses from severe winter prior to flooding in addition to flood and blizzard events: https://beef.unl.edu/beefwatch/extreme-weather-events-and-livestock-indemnity-program
- Article I’ve promised for a few weeks regarding the extreme winter before the flood/blizzard event: https://beef.unl.edu/beefwatch/considerations-attributing-livestock-losses
- Flood damaged grain and hay is considered adulterated and cannot be used as a food or feed source; it must be properly disposed: http://deq.ne.gov/publica.nsf/pages/11-023
- Post bomb-cyclone recovery
- Wet hay has the potential to combust so remove hay from building structures if impacted by flooding. Best practice for flooded hay and silage is to dispose of by spreading on fields as a fertilizer. Most practical way may be just unrolling bales for now. Hay bales that are at 30 to 40 percent moisture content pose the greatest risk of fire. Check hay storage often for pungent odors, hot damp areas on the stack, emission of water vapors and other signs of heating. To check a stack’s temperature for fire risk, drive a sharp pointed pipe into the hay, lower a thermometer inside the pipe and leave it there for about 20 minutes. At 150 degrees F, the hay is approaching the danger zone. At 170 degrees F, hot spots or fire pockets are possible. Have the fire department on standby.
Flooded Grain Bins: Flooded grain is considered adulterated and needs to be disposed. Grain above that can be salvaged by removing it from the top or side of bin with a tool like a grain vacuum. This article shares info. on considerations and grain vac service/suppliers: https://cropwatch.unl.edu/2019/grain-vacuum-services-rentals-suppliers
Flooded Pesticides: https://www.ag.ndsu.edu/flood/farm-ranch/flooded-pesticides
I don’t have room to mention all the resources! Please check out: https://flood.unl.edu/
Please keep talking to each other, share your stories, and don’t isolate! Eat a good meal, drink plenty of water, get some rest and be mindful of your personal well-being. Recovery is a marathon, not a sprint. We’re all being impacted by this. #NebraskaStrong is so true. It also takes strength to ask for help when we need it; help is always available!
- Nebraska Farm Hotline/Rural Response Hotline: 800-464-0258.
- The Nebraska Counseling, Outreach and Mental Health Therapy (COMHT) Program: 800-464-0258.
- Nebraska Family Helpline: 888-866-8660
