This post shares observations of what I’ve been seeing in fields pre-harvest and during harvest during this 2018 growing season. Some of these problems stemmed from hail/wind damage and others insect damage. This is a longer post with the desire to have many resources available to you in one place. Hopefully this will be helpful for diagnosing concerns as harvest continues.
(Photos above) Hail-damaged soybeans pre-harvest. The plants in this field weren’t pummeled into the ground, but from the road it was deceiving as to what the soybeans were actually like on these plants. The two smaller photos are all the soybeans found on 2 adjacent plants from the top soybean photo pre-harvest. There were a lot of aborted pods on stems and moldy beans in general. For those who combined hail damaged beans in the area, farmers shared they had everything from ‘lima’ beans to shriveled, moldy beans as you can see in these pics, which is also what we were anticipating may be found.
Cladosporium ear and kernel rot seen on kernels already affected by Fusarium, particularly in hail damaged fields. This is a lesser ear rot fungi and doesn’t produce a mycotoxin but can create increased damage to kernels. Was recommending taking grain damaged to this extent directly to the elevator.
Photos above shared by a Clay County farmer who observed kernel germination and Fusarium growth (mostly due to western bean cutworm damage) upon harvesting his field. Hormonal balance within the kernels shifts towards harvest. At full maturity, very little abscisic acid (ABA) is left in the kernel (in both corn and soybeans) which allows them to germinate in correct conditions after harvest. These conditions include moisture and temperatures above 50ºF. Presence of fungi such as Fusarium and Gibberella also increases gibberellins in the kernels allowing for kernel germination with presence of moisture as we’re seeing this harvest. Increasing air flow during harvest will hopefully blow most of these damaged kernels out the back of the combine.
- Corn Ear Rots, Storage Molds, Mycotoxins, and Animal Health, ISU, 1997. (Nice comprehensive resource available in PDF download via web search)
- UNL Corn Disease Profile III: Ear Rots
There’s over 25 species of fungi that can produce ear molds with the majority of them ceasing growth at 15% moisture within the kernel. Thus, we recommend drying grain to 15% moisture as quickly as possible to cease 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.
- Management of in-bin natural air grain drying systems to minimize energy cost
- Grain storage management to reduce mold and mycotoxins (ppt presentation)
- UNL CropWatch Grain Storage Resources
- Managing large grain bins for potential mycotoxin contamination
In 2018, 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.
- Grain storage management to reduce mold and mycotoxins (ppt presentation)
- UNL CropWatch Grain Storage Resources
- Managing large grain bins for potential mycotoxin contamination
- Understanding Fungal Toxins UNL
- Sampling and Analyzing Feed for Toxins UNL
- Use of Feed Contaminated with Fungal Toxins UNL
- Feeding Storm Damaged Corn: A few thoughts from a Veterinarian
Also, there’s a new app called “Mycotoxins” and it’s another resource with ear rot pictures and mycotoxin information put out by several Universities produced for both Apple and Android devices.
Reminder of South Central Ag Lab Field Day August 29th from 8:25 a.m.-4 p.m. (Registration at 8 a.m.)! 10.5 CCA credits have been applied for. More information at: https://go.unl.edu/zvwx
Crop Update: The rain last weekend was a blessing to many. It along with cooler temperatures has allowed for deeper kernels and delayed corn maturity. In fact, if we were to stay at the high temperatures we were experiencing, the Hybrid Maize model was predicting maturity in our area anywhere from 1-3 weeks early. Now, it’s mostly just predicting one week early (for anything that isn’t already mature). It also is showing above average yields for non-irrigated corn where drought-stress and hail weren’t a factor. Irrigated yields are showing near average according to the model for most fields in the area. You can see all the graphs and read more in this week’s CropWatch at http://cropwatch.unl.edu. Corn has reached black layer in many of the hail damaged fields I’ve looked at and some of the drought-stressed fields will begin harvest in a few weeks. The rain also greatly helped the soybeans, even in drought-stressed areas.
However, the rain also greatly increased stalk rot in fields, particularly in hail damaged ones. We weren’t seeing a large amount of mold in the first 7-10 days post-hail in hail damaged fields that were late dough to early dent. Now, nearly 21 days later, we’re seeing fungal growth increasing with the moisture and humidity within the husks of corn ears. It will be very important to check your fields to determine worst ones and worst areas of fields regarding stalk rot and kernel damage. Those areas should be harvested first if they’re being taken for grain and we’re recommending to fill any contracts with grain from those areas first. In checking for stalk rot, I prefer a ‘pinch test’ compared to a ‘push test’. With the pinch test, take your thumb and first finger and pinch the stalk internode that occurs between the lower nodes above the soil line. Do this for 20 plants in an area and get a percentage for those that crush. Then do this for several areas of your field. This gives you an indication of the level of stalk rot for your field and worst affected areas.
Cover Crops: With recent crop insurance determinations on these damaged fields, I’ve received an increasing number of questions regarding cover crop use. We’re already seeing weeds germinating in these fields due to open canopies, so weed control is one considerations for using a cover crop right now. Other reasons expressed have been for excess nitrogen uptake and also for a forage option. Dr. Mary Drewnoski, Extension Beef Nutritionist, Dr. Daren Redfearn, Extension Forage Specialist, and I talked through options to consider right now.
Always check with your crop insurance agent before seeding a cover crop into hail-damaged fields. It’s also important to check replant, forage and grazing restrictions regarding the herbicide program you used and any delay necessary before seeding a cover crop and any forage restrictions to grazing a cover crop. (See Replant Options and Herbicide Rotation Restrictions and Forage, Feed, and Grazing Restrictions for Row Crop Herbicides, both excerpted from the 2018 Guide for Weed, Disease, and Insect Management in Nebraska, EC130.)
In general, we’re at an interesting time for making cover crop decisions. Typically we use September 1 as the divider between planting small grains such as oats that will winterkill and winter hardy cereals such as rye or triticale (planted after September 1). Even with brassicas such as turnips, collards, or rapeseed, we’d recommend the cutoff for seeding to be within the next two weeks. Because of this time frame, mixes may be beneficial because they’ll take advantage of whatever weather we have for the rest of the season. Simple, inexpensive mixes may allow for at least something to become successfully established. So, for those looking at something to winterkill, oats could be planted yet this week as could a mix of oats and brassicas. However, after this week, we’d be looking at either adding something like rye or triticale to the mix or just switching to the more winter-hardy small grains. And honestly, while it isn’t mentioned in the table, if a person’s goal is cover the ground for weed management, bin-run wheat is also an inexpensive option. Your local seed supplier can provide seeding rates for cover crop options and we’ve provided a table with these options, depending on your goals, at http://cropwatch.unl.edu.
Yellow or red tops in corn plants: For a month now, we’ve observed yellow tops in corn plants. Plants that contain ears and are turning yellow from the top to the middle of the plant can be occurring because of anthracnose top dieback or another disorder called ‘top leaf death or dieback in corn‘. Some plants with this discoloration truly do have anthracnose spores present on the stalk and sheaths. However, there have been other situations where I couldn’t find the presence of anthracnose spores. In those situations, the plants were often on compacted areas of field edges, always had a nice ear on the plant, and sometimes had tillers as well. Dr. Bob Nielsen at Purdue mentioned they had found what’s called ‘top leaf death’ in corn in situations where they experienced more drought or heat stress. Those plants had leaf discoloration similar to anthracnose top dieback, but without the presence of the spores. So, for those situations where I’m not finding anthracnose spores, I’m calling it this top leaf death disorder. You can read more about this at: https://www.agry.purdue.edu/ext/corn/news/timeless/topleafdeath.html.
|COVER CROP||USE/GOAL||WHEN TO PLANT||HOW TO SEED||RATE
|OATS||Weed Management||By Sept. 1||Drill best. Can fly on.||30-40 lbs||*|
|OATS/RYE MIX||Weed Management||By Sept. 1||Drill best. Can fly on.||30 lbs each||*|
|OATS||Forage||By Sept. 1||Drill best. Can fly on.||80-90 lbs||*|
|OAT/RYE MIX||Forage||By Sept. 1||Drill best. Can fly on.||30-40 lbs of rye and 50-60 lbs oats||*|
|BRASSICAS (TURNIP, COLLARD, RAPESEED)-NOT OILSEED RADISHES||Cover ground, forage, nitrogen uptake||By Sept. 1||Fly on for quicker establishment.||5-6 lbs||—|
|RYE||Weed management, cover ground, forage, nitrogen uptake||After Sept. 1||Drill best. Can fly on.||50-60 lbs||*|
|*If adding a brassica to any of these small grain options, only 2 lb/ac is needed. Rapeseed isn’t as well known, but is an inexpensive and good option for consideration.|
Hail Damage Info: Thank you to all who attended our hail damage meetings last Monday and we truly hope the information was helpful. It was a lot of information at one time, so I have compiled it at: https://jenreesources.com/2018/08/14/late-season-hail-damage-resources/.
The ‘blessing’ in the timing of these later-season storms is in the reduced kernel moisture and shorter length of time till harvest. This is important to reduce the time for fungal growth in the ears. If you missed the meeting, presentations and information are at the link above. The main key I will stress: Please, ask your crop insurance agent how he/she wants to handle grain quality at harvest. Does the agent want to take samples for mold/potential mycotoxin? Does the agent go off of COOP samples? Does the agent require samples prior to going in the bin? These are key questions as we do know there is fungal growth on damaged ears. The presence of fungal growth does not automatically mean the presence of a mycotoxin. However, if grain quality isn’t handled and documented correctly at harvest, it can mean the loss of compensation if grain goes out of quality in storage. If anyone is taking hail damaged corn for silage, Dr. Mary Drewnoski is interested in samples prior to and after ensiling and is willing to help with sample analysis cost. Even if silage has already occurred, we’d be interested in samples after ensiling. Please contact me if interested. I will share additional considerations next week, but please check out the weblink above (or if it’s easier just go to http://jenreesources.com). Please let me know if you have any questions!
York County Corn Grower Plot Tailgate will be held from 5-7 p.m. on August 23rd. The plot is located east of York on Road 14 between Roads O and P on the north side of the road. View hybrids and visit with company representatives. Also, provide your estimate of the highest yield of the plot without going over. The winner will be awarded a Yeti cooler at the York County Corn Grower banquet in November. Pizza and beverages will be provided. Hope to see you there!
South Central Ag Lab Field Day will be held Wednesday, Aug. 29 from 8:55 a.m. to 4 p.m. at 851 HWY 6 near Harvard, NE. The day will begin with registration at 8:30 a.m., followed by tours of research sites through 4 p.m. Keynote speaker for the lunch is Mike Boehm, University of Nebraska-Lincoln Harlan Vice Chancellor for the Institute of Agriculture and Natural Resources and University of Nebraska vice president. Participants will be able to choose from four of the following six tours during the day. View program brochure for schedule.
Topics include the latest research in: Cover crops to corn issues; Corn insect management; Comparisons of variable rate irrigation and fertigation to fixed rate and impacts of cover crops on soil quality; Nitrogen fertilizer management (inhibitors and sensors) in irrigated corn; Corn and soybean disease updates; and Opportunities and challenges for weed control in soybean. CCA credits have been applied for. To register, please go to: https://go.unl.edu/2018scalfieldday by Aug. 26 for lunch planning purposes. Directions: 13 miles east of Hastings on Hwy 6 or 4.5 miles west of the intersection of Hwy 14 and Hwy 6. north of Clay Center.
Hamilton County Corn Grower Plot Tour will be held August 29th beginning at 11 a.m. The field location is just west of M Road and Hwy 34 on the south side (4 miles west of the Hwy 34 and 14 junction in Aurora), just past the viaduct. The program will feature Tom Hoegemeyer talking about the history of corn and how plant breeders have improved the yields. Kelly Brunkhorst, Executive Director of the Nebraska Corn Board will round out the program with an update on trade, the farm bill, and tariffs. Lunch starts at noon at the Oswald Farm followed by the featured speakers. The farm is located from L Road and Hwy 34 (5 miles west of the Hwy 34 and 14 junction in Aurora), 1 mile south to 12th Rd., then 1/2 mile west on the south side of the road.
Irrigation Field Days: Field days on Aug. 27 and 28 will demonstrate soil water measuring tools in production fields designed to help growers feel confident with their irrigation scheduling decisions. The demonstrations will show several irrigation scheduling equipment systems that were installed in the field this summer and have been recording data. Field Days will be located:
- August 27 – near Broken Bow. The August 27 presentation will be part of the Custer County Corn Growers 2018 Field Day at the Jeremy Coleman farm near Broken Bow. The tour will start at 5:30 p.m. at the field site, located five miles west of the intersection of Hwy 2 and Callaway Road then south ¾ mile on 433 Road. A meal will be served about 6:30 p.m. at Coleman’s shop one mile east of the field on Road 798. The educational program will be presented during the meal.
- August 28 – near Bradshaw. The August 28 tour will start at 12 p.m. with field demonstrations of the irrigation scheduling equipment, followed by a meal and presentations in the farm shop. The Bruce Hudson farm is at 2405 Road G, Bradshaw. That is 3.5 miles east of Polk on Hwy 66 to Rd G and 2 .7 miles south or from Benedict (Hwy 81 & State Spur 93C) 6 miles west to Rd G and 2.25 miles north.
It was great to see so many fields of corn and even soybean emerging throughout the
area this past week! Also grateful for the rain we received in York and for those who received some in other areas. There are still areas who continue to miss rains and I remain concerned about the soil moisture situation. I have another soil moisture update this week at http://jenreesources.com if you’re interested in checking that out.
Thursday night/Friday morning’s high winds caused some damage with overturned pivots/corner systems and tree damage. We also saw newly emerged corn and even soybean cut off or
buried due to blowing debris/soil, particularly in soybean stubble. It will be important to watch the plants in these fields the next several days. By late Friday afternoon, I was already seeing new growth occur, which is good. Typically, that has been the response in the past-new regrowth in corn as the growing point is still below ground. However, it will be important to watch the corn plants for any bacterial issues that may kill seedlings. One can also split open a few plants and look for a healthy growing point. Regarding the soybean, I have seen soybean lose cotyledons due to hail, crusting, freeze, and wind damage, and still produce a plumule at the top of the soybean stem. It’s just hard to know for sure what will happen so it’s best to watch the plants in the fields.
Wheat in Nuckolls, Thayer, and Webster counties ranges from elongation to near boot and is turning blue-gray from moisture stress. Wheat is a crop that I’m always learning about-it can look really bad (or really good) and then end up surprising a person regarding yield either way. Lower leaves
in fields are turning yellow-brown. Some of this is due to moisture stress while there’s also powdery mildew pretty thick in lower canopies of wheat that had more tillers. A few have talked with me about using the wheat for hay or silage and then potentially going in with short season corn, sorghum, or a forage crop. Our forage specialists would recommend that if the wheat variety has awns, it’s best to either take for hay or silage at the boot stage so the awns don’t cause issues with livestock feeding. Todd Whitney, Extension Educator in Phelps/Gosper counties, had worked with a feedlot using an awnless wheat variety. Because of the additional growth that occurs in wheat (and other small grains) from boot to full head elongation, they found biomass production may be increased 25% if the forage was harvested during the later pollination period.
Evergreen Trees: There’s also been a lot of evergreen tree questions. For those noticing spruce trees looking kind of yellow with early morning sunlight, spruce spidermites have been working hard with the cooler, dry weather. They tend to build populations in spring and fall. You can check for spidermites by taking a white piece of paper and banging the needles on it. Then look for the presence of tiny dark green to nearly black spidermites crawling on it. Rainfall is a great way to wash them off of trees as are strong streams of water (easier done with smaller trees). There are also a number of miticides available that homeowners can purchase from lawn and garden stores (look for products that say they can be applied to trees for control of spidermites). A great brochure on insect pests of evergreen trees can be found at: https://nfs.unl.edu/documents/foresthealth/insectevergreen.pdf.
Many of us also noticed our spruce trees turning red/brown/purple/yellow in color last fall. This is most likely a disease called needle cast of spruce and can be prevented by spraying trees now (mid-May) with a product containing copper sulfate. Regarding Ponderosa or Austrian pines, if you look closely at the needles and observe dark bands or rings on them followed by death of the needle either direction from the band, the tree problem is most likely due to a fungal needle blight like dothistroma or brown spot in Scotch pines. They can all be prevented by spraying a fungicide containing copper sulfate now. The following brochure on diseases of evergreen trees is really helpful: https://nfs.unl.edu/documents/foresthealth/diseasesevergreen.pdf. Sometimes the problem is finding the products listed on these brochures in our smaller towns as these brochures were developed in Lincoln. If these specific products aren’t available from your local lawn/garden store, box store, or coop, I would recommend looking at the products available and look for a product that says it is effective against needle blights on trees. Not all the products I’m seeing have copper as an active ingredient, but other fungicides are listed and the key would be the fact that the site (trees) and even better, the site with problem (trees with needle blights), is listed on the label.
We also continue to see pine wilt affecting our Scotch (short needles in groups of 2) and Austrian pines (long needles in groups of 2). Pine wilt disease is caused by the pinewood nematode that is carried within the gut of a long-horned beetle. The beetle is what creates the ‘shotholes’ often seen in bark of infected trees. The nematode is native to Nebraska, as are Ponderosa pines (long needles in groups of 2 and 3). This is why we don’t see the problem in Ponderosa pines but do in Scotch and Austrian, which are non-native to Nebraska. A tip, if you’re trying to distinguish Ponderosa vs. Austrian pines, anytime you see needles with a group of 3 it’s a Ponderosa. Pine wilt is caused by beetles carrying pinewood nematodes vomiting them into the water-carrying vessels of the tree (xylem). The tree senses the nematodes and essentially blocks water to those branches. Often you will observe a branch then perhaps a side of the tree and eventually complete death of the tree within 6-9 months. While I have diagnosed many samples of pine wilt, more often when I visit homeowners the tree problems are due to fungal diseases which occur on the needles.
Lawns: Please remember the importance of sweeping or blowing fertilizer and pesticide products back into the lawn instead of leaving them on sidewalks. Leaving them on the sidewalks puts them in contact with people and pets walking on sidewalks and moves them into storm water systems via rain that can eventually end up in streams. I’m also seeing a number of 2,4-D/dicamba products being sprayed around tree bases to kill weeds which is affecting the new growth emerging on trees. Consider applying a wood mulch layer around the base of trees to help avoid this situation in the future and be sure to read and follow all pesticide labels.
On August 1, 2013, a severe wind and hail storm damaged 170,000 acres of corn and 86,000 acres of soybeans in Clay County, Nebraska. Corn at the time of the storm was from brown silk-blister. While the storms in the Gibbon/Blue Hill areas occurred a little earlier in the growing season, the following photos show the progression of damage in the event it can be of help to those affected by 2014 storms.
The Mother’s Day 2014 storms caused significant damage in Clay County and other areas of the State. It never ceases to amaze me how people throughout the area respond to storm damage! Clay County has had its share, and yet the attitude of those affected has been one of thankfulness-thankfulness that no one was injured and that so many still have their homes in spite of damage. It’s also wonderful to see people from all over the County and area pull together with each storm-helping each other out bringing themselves and equipment to pick up debris or help however possible. It’s a blessing to work with and serve the people of this County!
As clean-up continues, the following are a list of resources that may be helpful to those affected by the storms. Thoughts and prayers go out to all who were affected!
- Numerous Tornado Damage, Recovery, Cleaning, Decision Making resources (scroll to Recovery portion in middle of page)
- Tips for Early Tornado Damage Recovery
- When to Save and Throw out Frozen Food after Power Outages
- When to Save and Throw out Refrigerated Foods after Power Outages
- Flooding and Corn Survival
- Flooding and Soybean Survival
- Evaluating the Need to Replant
Special thanks to Dr. Scott Dewald for the wonderful evening of information he provided at our tree care workshop last week!
This was a fun workshop for me with the right size of group and great hands-on demonstration where we also learned from pruning mistakes and how best to correct them. Thanks again Scott!