Category Archives: Crop Updates

JenREES 6-16-19

Crop Update: This past week’s top question was about yellow looking and/or buggy whipped corn and weed control. Much of what we’re seeing can be attributed to cool, wet conditions this spring. Yellow striping on leaves is often due to sulfur deficiency but could be combined with other nutrient deficiencies depending on conditions. Purdue University has a nice guide with pics if you’d like to check it out: https://www.agry.purdue.edu/ext/soilfertility/news/Striped_Corn.pdf.

Most of what I looked at or received questions about was yellow and/or buggy whipped corn due to herbicide injury. This isn’t uncommon for pre-plant residual herbicides to impact corn more in years where we have wet conditions, cooler temps, and plants that are slower to emerge/grow. Yes, some of these products are considered ‘safe’ for corn, and they shouldn’t kill it. It’s just we’re experiencing a strange year with cool, wet conditions and the corn is metabolizing the chemical but not growing fast enough, thus the injury. Situations which may be extra sensitive are ones in which corn was planted too wet with slots not closing or if corn was planted too shallow. Soil applied grass herbicides and those with pre-mixes containing atrazine may be experiencing more of the buggy whipping or yellowing from Group 15 growth inhibitor herbicides. Yellow/purple leaves and sometimes ‘bottlebrush’ looking roots can be exhibited from Group 2 ALS-inhibitor herbicides. Herbicides in Group 27 with ‘bleacher’ chemistry are re-activated with rain events and we’re seeing some yellow/white corn and milo due to that. Dr. Kevin Bradley, University of Missouri, wrote an article that shares photos and trade names if you’re interested in checking that out: https://ipm.missouri.edu/IPCM/2009/4/Cool-Wet-Soils-Can-result-in-More-Corn-Injury-from-Preemergence-Residual-Herbicides/. I realize it’s frustrating, but overall these are good products and it’s the weather conditions causing the problems. Each day of sunshine and warmer temps are helping corn to grow out of the symptoms and look greener/healthier in most cases.

The other concern is the rain has moved herbicides down into the soil and we’re beginning to see weed flushes of waterhemp and palmer on the soil surface. Chris Proctor, Extension Educator, addressed this in CropWatch and Nebraska Farmer as we think of post-emergence control right now in both corn and soybean. There are additional trade names with similar chemistries mentioned and this isn’t an endorsement of specific products. “There are a number of effective herbicide options in corn such as Acuron, Laudis, or Diflexx Duo. In soybean, herbicide options are much more limited. When coupled with traited seed, Liberty, or Xtendimax can be effective at controlling these weeds postemergence, and in a Roundup Ready system Warrant Ultra or Flexstar GT are good options. It’s not too early to plan how to improve weed control in fields with a history of difficult-to-control weeds. A good preemergence herbicide program, use of narrow row-spacing, and even cover crops, when used as part of an integrated management plan, can improve control of herbicide-resistant weeds.”

Thistle Caterpillars: Painted lady butterflies migrate north from the southern U.S. and

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This caterpillar still has several weeks (2-5 depending on weather) of feeding.

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This caterpillar will begin pupating within a week.

Mexico each spring. The butterflies have been around for a little over a month and thistle caterpillars have been found feeding in soybean the past few weeks. Last week, I was seeing higher populations in early planted soybeans in Clay and Nuckolls counties. Larvae can feed from 2-6 weeks depending on weather. Treatment thresholds for vegetative stages are 30% defoliation. Each field needs to be assessed regarding percent defoliation and larval stage. Some fields I checked had larvae that were pupating or already emerged as adults. Other fields had larval stages that will still feed 2-5 weeks, depending on weather. Much information we read says they stay on field borders, which I’ve seen to be true later in the growing season. But right now, I’m finding situations where they’re fairly consistently infested throughout the field. Some may consider adding an insecticide to your post-herbicide application. If you have dicamba-tolerant soybeans, be sure to check the product’s website regarding approved tank-mix partners.

Irrigation Scheduling Workshops for wet years will be held Wednesday June 19th, 12 noon, at The Leadership Center, 211 Q St (E Hwy 34) in Aurora and Tuesday June 25th, 12 noon, at the Chances R Restaurant, 124 West Fifth Street, York. The program will start with lunch at 12:00 pm, followed by the speakers and wrap up around 1:30 pm. The Upper Big Blue NRD will provide the lunch. RSVP is not required but appreciated for a meal count. Call the Hamilton County Extension office at 402-694-6174 or email Steve Melvin at steve.melvin@unl.edu. Dan Leininger with the Upper Big Blue NRD will speak on installing sensors and Steve Melvin will speak on deciding when and how much water to apply using watermark sensor readings.

JenREES 6-9-19

Crop Updates: It’s been interesting seeing growers sharing pics comparing crops on the same dates in 2018 to 2019. They are behind in many cases compared to last year. Yet, we can be thankful for every field that we’ve been able to plant in Nebraska this year! Weed control is something on many minds right now. On corn, please be sure to count collars to determine growth stages. First leaves are sloughing off on V5-V7 plants right now, so slitting open stalks to aid in counting collars is important as we think of herbicide applications. Bob Nielsen from Purdue has a nice recent article with photos to help you with this: http://www.kingcorn.org/news/timeless/VStageMethods.html. When it comes to beans, I’m concerned how much longer the PRE’s will hold. I share this every year in pesticide training to have the POST with residual on a week before you think you need it, even if you don’t see weeds in the field yet. So assess each field as to when your PRE went on, current weed emergence, and plan on your POST a week earlier to overlap when your PRE residual should be running out. Also, with palmer amaranth on people’s minds, consider attending a glyphosate resistant palmer amaranth field day July 10th near Carleton, NE. Dr. Jason Norsworthy from the University of Arkansas will be the featured speaker. For those who’ve heard me speak on palmer or at my pesticide trainings, much of what I share has been what I’ve learned from his presentations and research papers. You can learn more and register at: http://agronomy.unl.edu/palmer. Adding a small grain and diversifying our cropping systems is one way to aid in palmer/waterhemp management. There are several upcoming wheat and pulse crop field days occurring throughout Nebraska in the next two weeks and you can read more about them at: https://go.unl.edu/b65e.

At some point, irrigation may be needed again. Installing irrigation scheduling IMG_20190609_193835equipment now allows you to watch your soil moisture profile as your crops grow, gain better confidence in your readings, and it’s just easier to install them at earlier growth stages when there’s moisture in the profile. Here’s some tips for those using watermark sensors. (As I walk through this, I’m using kilopascals (kpa) for the sensor readings but the same numbers apply to centibars (cb)). First, be sure to prime the sensors to ensure they’re working correctly. Do this by soaking the sensors for at least 24 hours in water. If you still have mud on the sensors, gently remove with your fingers, not with a brush. Then check the readings to ensure they read 10 or less. If they don’t, I allow them to soak another 24 hours and recheck; replace any that don’t read 10 kpa or less. Allow the sensors to dry out to 199 kpa again by setting out in the sun/wind/blowing fans. (Note that water will move into the PVC tube during soaking, so you’ll need to remove the cap and dump the water out if you don’t have a hole drilled at the bottom of the PVC tube. This is also true during the installation process.) When you’re ready to install the sensors, they need to be soaked again, but it should only take them 1-5 minutes to read 10 kpa or less prior to installation. There’s a couple things I’ve learned with installations that help me. First, use an ag consultant’s tube on soil probe to dig the foot wherever the sensor is installed. This allows for a better fit with no air gaps along the sensor. I use a regular soil tube to dig the hole the foot/feet above that to aid in pushing the sensors. In wet, clayey soils, it can be difficult to push the PVC pipe into the ground, so digging the upper holes with a bigger tube helps me with that. The other thing I do is carry my bucket with water for the sensors to the field with me with the sensors. To aid with pushing the sensors in the ground, I wet the PVC tube with water from the bucket prior to installing it. NEVER pour water into the holes and don’t make a slurry mix. I’m hearing several were taught to do this, but it’s not what Nebraska Extension teaches based on Dr. Suat Irmak’s research as it will change the soil moisture of the holes compared to the surrounding soils. Make sure the sensors hit the bottom of the hole and fill in soil where the PVC pipe meets the soil line. Suat shared how he used rubber washers around the top of the PVC pipe at the soil line to aid in water not running down the PVC tube when soil cracks at the surface. For those installing ET gages, a reminder to remove the stopper from the ceramic top and fill the ceramic top with distilled water in addition to the main tube of the ET gage. I fill the ceramic top, allow it to soak into the ceramic plate a little and refill it. Then prime the inner tube with stopper ensuring there’s no air bubbles in the small tube after placing it into the ceramic top. You can also double check for air bubbles by gently removing the glass site gage (by pressing down on the rubber tubing at the base of the site gage), allowing some water to cycle through, and then replacing it.

Maple seedlings: Maple trees have now leafed out and the rain has allowed the abundance of seeds to produce seedlings in people’s lawns and gardens.  I know they look bad because they do at my place too. Mowing is the best way to take care of them in your lawn and it will take several mowings to do so. Don’t lower your mowing height as you want to maintain a healthy grass canopy. Eventually the seedlings will continue to grow to where the mower blade cuts off below the growing point and the seedlings will die. In the flower beds, they are very easy to pull right now. It takes some extra time, but that’s the best way to rid them there.

 

JenREES 6-2-19

Flooded Gardens: This was my top question last week. For those of you with flooded gardens due to ponding of rain water, it will be fine to use your produce and the following information won’t pertain to you. However, most of the calls I received were from those with creeks or rivers that flooded their gardens. In that case, it’s difficult to know what contaminants may be in the water. It’s recommended by our Extension horticulturalists to wait 90 days to use any produce that does not have contact with the soil and 120 days to use any produce that does have contact with the soil. For example, tomatoes, peppers, eggplant, green beans could be harvested and eaten after 90 days. Fruit from trees and shrubs could be harvested and used after 90 days. However, rhubarb, potatoes, asparagus, squash and melon crops would need 120 days before harvesting to eat. Vegetables/fruits that are produced prior to the 90 and 120 day waiting period should be removed from plants and discarded. If the actual plants such as tomatoes, peppers, beans, etc. survive flooding, they do not need to be removed or replaced. You can allow them to continue to grow, just don’t use the fruit till 90 days post-flooding. Additional information can be found at: https://grobigred.com/2019/03/22/gardenflood/amp/?. Also, don’t harvest the morel mushrooms that are abundant this year due to the contaminants they’ve potentially been in contact with.

Crop Considerations: If you’d like more in-depth information regarding flooded/ponded corn/soybean, please check out this week’s CropWatch at http://cropwatch.unl.edu. We also shared a replant considerations article for corn in CropWatch. The tables in that article will be helpful as one assesses stands. Check corn, soybean, and milo for new regrowth 3-5 days after water recedes to determine potential survival. When it comes to assessing soybean stands for replant considerations, most UNL agronomists would say to leave stands of non-irrigated at 60,000 plants per acre and irrigated at 75,000 plants per acre. Honestly, my cutoff is 50,000 plants/acre for both irrigated and non-irrigated based more off of observation. A few on-farm research studies with lower actual stand counts include the following examples. 1-A non-irrigated field in Nuckolls County in 2006 was hailed at the cotyledon stage, so planted populations of 100K, 130K, and 160K became average actual stands of 74,417; 89,417; and 97,917 plants per acre with a 4 bu/ac yield difference between highest and lowest plant populations. 2-An irrigated field in Hamilton County in 2010 showed a 3 bu/ac yield difference between planted stand of 80K vs. 120K seeds/acre. 3-A York County irrigated field in 2018 comparing 90K, 120K, and 150K became final plant stands of 60,875; 88,125; and 121,750 plants/acre with yields of 93; 94; and 97 bu/ac respectively. So soybeans greatly compensate for reduced populations. Weed control may be another factor, depending on time of year, for soybean replant consideration. When in doubt, leaving some strips with the original stand and others with replant to test is also an option.  I’ve also received questions regarding how much nitrogen to expect in the flooded/ponded soils. I don’t have a good answer other than soil samples will be helpful in determining this.

Wheat Diseases: I didn’t find any pustules looking at wheat in Nuckolls and Clay this past week. Stripe rust was confirmed in Perkins County and it was also found in Hamilton County by a crop consultant. While the model wasn’t showing as high of a risk, I’ve been concerned about our potential for wheat scab this year with all the rain. There are early planted wheat fields in which the flowering process has been completed. But there are a number of fields that are just fully headed now with beginning flowering to start soon. Upon flowering, your options for controlling any fungal diseases present on leaves as well as preventing scab are Prosaro, Caramba, and Miravis Ace. Research has found best timing to prevent scab is when 30% of the heads are at 15% flowering…basically early flowering. Flowering in wheat begins in the middle of the head.

South Central Ag Lab Weed Science Field Day: June 26th will be the South Central Ag Lab Weed Science Field Day near Clay Center. The field day will run from 8:30 a.m. to 1 p.m. with registration beginning at 8 a.m. Tours include: New Technology/Herbicides for Weed Control in Soybean; Herbicides for Weed Control in Corn; and a presentation by Bob Klein on “What Works and Doesn’t Work in Managing Spray Drift”. There is no cost to attend and CCA credits are available. Please pre-register at: http://agronomy.unl.edu/fieldday.

Keeping Rural Worksites Strong:  This is a workshop for those who work in human resources, leadership and wellness roles, agriculture, and safety to create a mental health friendly workplace.  It will be held on Tuesday, June 25 from 9 a.m.-4 p.m. (Registration 8:30 a.m.) at the Seward Medical Center in Seward. Topics include: stress and employee health; substance use issues in the workplace; identifying risk for violence in the workplace; employer’s role in preventing suicide; caring for employees; and being a mental health friendly worksite. Cost is $20 and includes light breakfast, lunch, and materials. Please RSVP to Four Corners Health Dept. at: http://www.fourcorners.ne.gov or (877) 337-3573.

JenREES 5-26-19

IMAG3602_1Driving through Nebraska towns around Memorial Day, I find the streets lined with flags such a beautiful site. Grateful to live in our Country with our freedoms. I’m also grateful for those who paid the ultimate price for our freedom and for their families left behind.

Flooding/Ponding and Crop Effects: With the rain, some may be experiencing ponding/flooding of crops. Emerged corn prior to 6 leaves can survive from two to four days depending on temperatures and if entire plants are submerged or not. Cooler air temperatures (60’s and cooler) allows for longer survival than temperatures in the mid-70’s and warmer. Little data exists for germinated seeds and seedlings prior to emergence, but they most likely would experience soil oxygen depletion within 48 hours. Once emerged, soybean may handle a fair amount of flooding due to the growing point being above ground (depending on if they’re submerged or not). Four or more days of flooding may result in shorter plants due to shorter internodes and/or perhaps fewer nodes. Stand reductions may be observed after seven days of flooding (depending on size and if completely submerged or not).

Prevent plant may be another topic on some growers’ minds in addition to considerations after the May 25 corn planting date for crop insurance. These are addressed in this week’s CropWatch at http://cropwatch.unl.edu.

Interseeding Cover Crops: In a previous news column, I touched on the topic of interseeding cover crops into corn or soybean. For this week’s CropWatch at http://cropwatch.unl.edu, we provide more information based on the research available. For those considering this as an on-farm research study, please contact me or your local Extension Educator soon to work out details.

Wheat: Michael Sindelar and I looked at wheat in Clay and Nuckolls counties last week. For diseases we’re mostly seeing powdery mildew and septoria leaf blotch. Backlighting revealing yellow specks on upper leaves in some fields will most likely develop into leaf rust. Wheat ranges from nearing flag leaf to beginning flowering. My concern for wheat in the heading to flowering stage is risk of fusarium head blight (scab) with the rain we’ve been receiving at heading/flowering. The scab risk tool (http://www.wheatscab.psu.edu/) is showing a low to medium risk for our part of the State right now. If you do consider a fungicide, your best options include Prosaro, Caramba, or Miravis Ace as these products will help protect against scab in addition to kill any fungal diseases on your wheat leaves. Other products are off-label once flowering begins or are not as effective preventing scab based on research. Best application timing to prevent scab is when 30% of the plants in the field are at 15% flowering (early flowering stages).

Lawn Care: I know some are getting tired of mowing already! Just a reminder to keep mowing heights at 3″. Spring is an important time for deeper root establishment before the summer heat sets in and maintaining a higher lawn height allows the grass to develop that root system. I’m seeing several lawns being scalped in an effort to reduce amount of mowing. Mowing too short stresses the grass impacting its ability to set deeper roots for later. It will also allow for more weeds to germinate in the lawn.

JenREES 5-19-19

What a blessing last week was for many to be in the fields to either finish or start planting! And, while some may not want it, we could also use some rain to help with the crusting issues that have been developing in various fields due to the warm temperatures and wind. As you assess stands, the following article provides some guidelines on what to look for and any replant considerations for corn: https://go.unl.edu/j727.

For those who planted soybean earlier into cooler soil conditions, Dr. Jim Specht also did so on different dates this year and monitored air/soil temperatures at the former ARDC near Mead. Air temperature daily lows were less than 36°F on eight days (five of which were 32°F or lower), were less than 40°F on 17 days, were less than 44°F on 23 days; and notably, were less than 48°F on 31 of the 37 days. I’ve talked about desiring a 24 hour window of near 50F temps for avoiding potential seed chilling of soybean. It’s based off some Canadian research that showed soybean completing the imbibitional (water uptake) phase in as little as 8-24 hours. Jim had a demo study this year in which he placed water into furrows and planted soybean seed 1.25” deep into the furrows on various days in April at 2:30 p.m. Adding water to the furrow was to hasten the imbibitional phase. There’s a slideshow with the full article in this week’s CropWatch at: https://go.unl.edu/yu2m. The article shows the seeds in this demonstration did not appear to be impacted by chilling injury in spite of low air/soil temperatures on some of the days including within a 24 hour period. The hypothesis is that planting in a warmer part of the day with good soil moisture allowed the imbibitional phase to complete more rapidly before the cold snaps occurred in the evening/following day. While this was only a demo, it spurs many questions. Further research to better document chilling injury and imbibitional period for different soil temps/moisture contents would hopefully help growers planting soybean in April.

Silver and Red Maple Trees: While back home helping with planting, I was also receiving numerous tree questions. For those with malformed leaves or various leaf coloration, I’m thinking that’s mostly due to the cool temperatures we’ve experienced. Malformed leaves can also be due to growth regulator herbicides such as 2,4-D (from weed and feed products or sprays) being applied to lawns when trees are beginning to leaf out.

For the past few weeks, I was observing the slow leaf-out of silver maples in town…even where portions of trees were leafing out and other portions seeming bare. Now, if your maples look like mine, they look brown and bareIMG_20190519_185322 with huge seed production and minimal leaves. This can also be seen in red maple varieties such as the popular ‘Autumn Blaze’ maples from my observation. For everyone who called or texted, I told you I was assuming it was due to the cold snaps and frosts affecting trees leafing out. It also could be a result of the hard winter. Trees are interesting as stresses from previous years can also affect them several years down the road. While all that’s true, what I didn’t realize is that based on information from Ohio and Michigan State, frost at specific times trigger whether a tree goes into seed or leaf production. Maple trees produce very small flowers that turn into seeds every spring. Frost will kill some of the blossoms if received at the right time which leads to less seeds and more leaves. Even though it was a cold spring, perhaps fewer blossoms were killed than normal at the right time? It could also just be the natural cycle of heavy seed production this year? Regardless, the trees can’t support both massive seed production and leaf production, so many opted for seed production. The good news is that shade trees in general have an ability to shoot new leaves after being stressed. I see this every year after trees lose leaves due to herbicide damage, insects, diseases, or environmental conditions. So, give the trees a couple of weeks and you should begin to see new leaves developing. Don’t add fertilizer or other products to them as it’s not necessary and can actually stress trees that are stressed even more. By summer, the trees should look fairly normal. If they don’t, perhaps there’s another stressor occurring with your tree? The biggest culprits I see are roots that girdle (choke) the tree by wrapping themselves around the trunk or damage to the trunk from weed whackers.

What about those seeds in lawns and gardens? Some pre-emergent lawn herbicides will keep them from sprouting. Pulling them is time consuming, yet a valid option that’s best done as soon as seedlings emerge. Mowing may help keep some of them at bay. Weed and feed products for lawns often contain 2,4-D so using that or lawn care products with 2,4-D can be an option (just be sure to read the pesticide labels). Products like Preen can be pre-emergent options for flower beds/gardens.

JenREES 5-12-19

Crop Update: It is really nice to see crops emerging! The corn, soybean and wheat I When estimating whether severely injured plants will survive, check the growing point. Healthy growing point is yellow/white and firm as is shown in this picture. Unhealthy growing point is discolored and soft to the touch.looked at didn’t seem too impacted by the frost. There may be places where crops were more affected. For corn and wheat, it’s important to look at the growing point and make sure it’s white/yellow and firm and not discolored and soft. Impacts to wheat later on can also be seen at heading in white awns. Soybean are more susceptible to frost when those hypocotyls are just emerged at soil level or above and exposed when frost occurs. Soybean with hypocotyls that are pinched and brown will probably not survive. Soybean that have light scarring of hypocotyls and cotyledons most likely will survive. Look for the plumule (first true leaves from the shoot) within 7 days post-frost to ensure the growing point wasn’t injured. (You can see the plumule between the cotyledons in the upper right-hand picture below).Frost on soybean.PNG

Hopefully we don’t have to deal much with replanting. As we assess stands, this week’s UNL CropWatch at http://cropwatch.unl.edu has an article regarding stand and replant considerations for corn. It’s important to take stand counts in several areas of the field. There’s a table on the CropWatch website which shows original planted stands with planting date and what can be expected for potential yields based on stand counts and replanting at a later date. Roger Elmore shared the following example, “If the original planting date was April 30, a population of 35,000 plants/acre is expected to provide maximum yield. If the population is only 20,000 plants/acre, yield potential is 89% of the maximum for the April 30 planting date. If several 4- to 6-foot gaps occur within the row, yields will be reduced an additional 5% relative to a uniform stand. Stand gaps of 16 to 33 inches will only reduce yield by 2%. Estimate replant yield with Table 2. Use planting date and target plant population to estimate the yield potential of the replanted field. Replanting on May 20 at 35,000 plants/acre will result in approximately 87% of the maximum yield. Compare the replanted crop to the original crop which was planted on April 30 that now has a population of 20,000 plants/acre, and consider the costs of replanting. Expected yields are 89% for retaining the old stand versus 87% for a replant. Remember though, there is no guarantee of getting a good stand with replanting. Insect and disease pressure may be greater in replanted fields.” You may also be interested in checking out a new CropWatch podcast on corn seedling diseases at: https://go.unl.edu/a5zf.

Interseeding Cover Crops: The past four years, some growers have shared with me an interest in interseeding cover crops into corn or soybean. The growers have different goals which may include fall grazing, additional nitrogen from the cover, or soil health impacts such as increasing soil organic matter. Because cover crop establishment after corn and soybean is more difficult and inconsistent year to year, there’s been an increasing interest in interseeding. Basically, the thought is to plant the cover before the corn or soybean crop reaches canopy closure. The cover emerges and then essentially doesn’t grow much during the growing season due to minimal light interception. After harvest, the hope is the cover has greater biomass production since it’s already established. Research in general from other states hasn’t shown yield reduction in corn when the cover was planted after V4…typically from V5-V7. When the cover was interseeded earlier, some states have found yield reductions as the cover basically competes like a weed with the corn for resources. A question we often receive is regarding herbicides.  Wisconsin shares that Sharpen and Resolve for herbicides allowed for greater success with short half-life. They planted radish, oat, pea, rye, red clover in their trials. A family conducting on-farm research in Merrick County has been interseeding the past three years. In their 2018 trial, they used 32 oz glyphosate + 5 oz Status per acre post on 6/1/18 (planting date 5/17/18). They interseeded on 6/26/18 with 6 lb cowpea, 6 lb soybean, 0.5 lb crimson clover, 5 lb sunhemp, 2 lb hairy vetch, 3 lb buckwheat, 0.5 lb chicory, 0.5 lb flax, 0.5 lb rapeseed/canola, 6 lb Elbon cereal rye, 6 lb spring oats per acre. From conversation they were happy with cover emergence after Status application but I failed to ask which species looked the best. They will continue the study for several years.  Outside of this, we have very little research from Nebraska and my hope is to obtain more research via on-farm research this year! We’ve created a 2 treatment and 3 treatment protocol which can be found at: https://go.unl.edu/kvjf. The three treatment protocol can be altered a number of ways: including looking at 2 different mixes compared to a check, looking at different ways of seeding the cover crop vs. check, and looking at different interseeding timings vs. check. Please contact me if you’re interested in trying this!

JenREES 5-5-19

Crop Update: Every year provides ample opportunities to learn and this year will be no different. We’ll learn a lot in the next few weeks with corn/soybean germination and emergence and the cold tolerance of seed. Grateful for the planting that’s been accomplished thus far! Some rainfall hopefully is providing a much needed break for some and could also help with the dry seed bed and crusting concerns with some fields.

I’ve seen information going around regarding delayed planting and changing to early relative maturities for corn. The concern is regarding frost occurring before the crop reaches black layer. We’re honestly too early for that conversation until we hit early June, but that may be a reality in portions of the State. When looking at the number of GDDs to Black Layer, it’s important to ask your seed company if that number is based on ‘from planting’ or ‘from emergence’. Bob Nielsen, Extension Specialist at Purdue, found from research conducted in the early 2000’s that when hybrids were planted late, they matured in fewer growing degree days (GDDs) than predicted. In their research, Bob and his team found that hybrids matured around 6.8 fewer GDDs for every day planted after May 1. This continued through the second week of June and they didn’t evaluate planting dates beyond then. He gives the example, “a hybrid rated at 2700 GDDs from planting to physiological maturity (kernel black layer) and planted on May 31 reaches physiological maturity in less than 2500 GDDs after planting (e.g., 2700 – (30 days x 6.8)).” Roger Elmore, Nebraska Extension Cropping System Specialist, put this in perspective in an older CropWatch article, “A 115 CRM hybrid (2782 GDD) planted on May 15 would behave like a 111 CRM hybrid and when planted on May 30 it would behave like a 107 CRM (2578 GDD) hybrid. If planted on May 30 this hybrid should mature around September 14 in southeast and southern Nebraska and around September 27 in central and northeast Nebraska.” So hopefully this is helpful with the upcoming weather forecast potentially delaying getting back into the fields. Bob does have a calculator at the following site which provides an estimated GDD adjustment when you plug in the GDDs of your current hybrids and your expected planting date: https://www.agry.purdue.edu/ext/corn/news/timeless/HybridMaturityDelayedPlant.html.

Renovating Flooded Pastures Workshop: After spring flooding, many river frontage pastures and crop fields were left with sand and silt deposits ranging from a few inches to up to three feet. Recovering that land for production will be the focus of a May 13 on-site workshop near Ravenna at 1:30 p.m. Jerry Volesky, Extension range and forage specialist, will discuss treatments and practices to aid land recovery. Participants are invited to park at McAuliff Farms at 41465 325th Road south of Ravenna. A tractor and trailer will transport attendees to the workshop location, where there are heavy deposits of sand and silt from flooding of the nearby South Loup River. For more information, contact Volesky at 308-696-6710 or  jerry.volesky@unl.edu or the program sponsor, Town and County Bank at 308-452-3225.

Tree and Lawn Care Programs for York and Seward Counties: Two upcoming tree/lawn care will be held in York and Seward Counties. Sarah Browning, Nebraska Extension Educator, will be presenting the programs. There is no charge but please RSVP to (402) 441-7180 to attend either or both programs.

  • “Made in the Shade: Trees for Nebraska’s Landscapes” will be held on May 30th from 6-7:30 p.m. at the 4-H Building at the Fairgrounds in York. Trees are the backbone of our landscapes, providing beauty, shade, noise reduction, wildlife habitat, and reduce home heating and cooling costs. In this program, learn how to keep your trees healthy and vigorous. We’ll also discuss tree species well-adapted to Nebraska’s challenging growing environment.
  • “Troubleshooting the Landscape” will be held on June 5th from 6-7:30 p.m. at the Civic Center in Seward. Learn how to better manage these common problems in your landscape: Emerald Ash Borer, Weed control in lawns and landscapes, Summer and fall lawn care, and Pruning trees and shrubs.

JenREES 10-28-18

Dates are something I tend to remember. This past week I was reflecting on a year ago: fire dangers with three wind events including the Thursday event that was the final straw, a beautiful Wednesday for getting plots out, and then Friday seeing the massive change in yields due to dropped ears. To me, many challenges began with last year’s harvest, and many may wish to forget last year. But reflecting also allows us to learn and count our blessings. Grateful for all the harvest that occurred the past couple of weeks with beautiful weather!…especially since things looked pretty bleak with all the rain and the snow event! Grateful for good yields overall and that we’re not dealing with widespread dropped corn ears at this time!

With the challenges on the soybean side, there’s two

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Soybeans showing discoloration from purple seed stain, Phomopsis seed decay, and potential stinkbug damage.

articles in this week’s CropWatch at http://cropwatch.unl.edu that may be of interest. One is about feeding soybeans to cattle. With reports of elevators rejecting soybean loads to the east of our area, we received questions if they could be fed. The Cercospora fungus causing purple seed stain and the Phomopsis fungus causing seed decay do not produce mycotoxins. We’re not aware of any soybean mycotoxins. We also don’t know how these fungi affect soybean seed quality regarding the feed value. So, we recommend testing for that if you’re interested in doing this.

Another article is by Cory Walters, UNL Ag Economist talking about crop insurance help with various dockage that one may have received. This fall’s weather could trigger indemnity payments due to low quality. This is just a short excerpt of his article. He writes, “The following discussion describes how crop insurance adjusts soybean yield due to quality for a particular county. While I have not found any differences in discount factors among counties, it is possible. The final outcome depends upon what the county actuarial documents stipulate. Discount rules contain quite a few if/then statements, so final outcomes will depend upon the particular production characteristics.

…Final yield is determined by multiplying the harvest yield by one minus the sum of all discount factors. Factors for each discount type are summarized as follows:

  • A sample grade outcome results in a 3% discount factor so no discount factors for any other grade.
  • For test weight, discount factors start at 48 to 48.99 lb with a discount factor of 0.7% that increases to a 1.5% discount factor with a 44 to 44.99 test weight. Test weights lower than 44 are settled through the other category.
  • Damage discounts start at 8.01% with a 4.4% discount factor that increase to a 25.2% discount factor with a 34.01% to 35% damage. Just like with test weight, damage over 35% are settled through the other category. Damage includes everything except heat.
  • Odor sample grade discounts are 2% for musty odor, 2% for sour odor, and 4% for commercially objectionable foreign odor (COFO).

For example, suppose your harvest soybean sample comes back as grade 4 with a 48.5 lb test weight and 9.4% damage. The field yielded 50 bu/ac. Yield would be reduced by 5.9% from the summation of 0.7% (test weight discount) + 5.2% (damage discount). Final yield would equal 47.05 bu/ac (50 x (1-.007-.052)). An indemnity will be paid if harvest revenue is less than guaranteed, which will vary among producers with different insurance products, coverage levels, and APHs.

Producers with multiple insurable units, likely coming from optional or basic units, should contact their insurance agent to determine the process for keeping samples of each unit. This is very important when soybeans are going to the bin. Quality discounts found here will likely not cover the entire price deduction found at the elevator. While this is unfortunate, some coverage is better than none. It is possible to get discount factors updated and/or modified for upcoming insurance contracts.” For questions and comments please contact Cory Walters at cwalters7@unl.edu and view the entire article in this week’s CropWatch.

Fall Burndown Apps is something we recommend, particularly if you have a problem with marestail or winter annuals like henbit in your fields. Nebraska data has shown over 60% of marestail germinates in the fall. Amit Jhala, Extension Weed Scientist shared an article in this week’s CropWatch. The following is a small excerpt, “Preliminary data for eastern Nebraska suggests that a fall burndown applied with a residual herbicide may eliminate the need for an early spring burndown for marestail control; however, this would not replace an at-planting residual application for management of additional troublesome weed species such as waterhemp and Palmer amaranth. For successful marestail management in the fall, apply herbicides following harvest while weather conditions remain favorable (air temperature above 50°F).

  • Glyphosate-resistant marestail is widespread across eastern Nebraska, thus 1 lb a.e. 2,4-D per acre is recommended as the base treatment for marestail burndown.
  • Glyphosate or other products such as Sharpen® or Gramoxone® may be tank-mixed with 2,4-D to provide broader spectrum control of winter annuals and certain perennial weeds.
  • We generally do not recommend including residual herbicides in fall applications since they provide little benefit in managing weeds that emerge the following spring; however, if infestation of marestail is high in the field and the field has a history of marestail seedbank, it would be advantageous to add a residual herbicide such as Authority® or Valor® or Autumn™ Super, or other metribuzin products.
  • Refer to the most recent Guide for Weed, Disease, and Insect Management in Nebraska for more herbicide options.

Fall herbicide application is unlikely to eliminate the need for burndown application at planting. Weeds adapted to cool temperatures, such as marestail, are likely to emerge prior to planting, making it necessary to control them.” He also shows photos in this Week’s CropWatch article of fall tillage or use of rye cover crop as additional options for reducing/suppressing marestail and other winter annual weeds.

2018 York Co. Corn Grower Plot Results

Thank you to Ron and Brad Makovicka for hosting the York County Corn Grower Plot again and for all your efforts with it! Thank you also to all the seed companies who participated!

June 30th wind event affected the tester in the stage of development it was in with greensnap-primarily above or at the ear node. Small ears developed and were included in harvest stand counts.

Rankings were based on adjusted yields (based on a formula for nearest testers) and two decimal places were used to break the tie.

York Co Corn grower plot 2018.PNG

Grain Observations

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.

Soybean Observations

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(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.

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Examples of soybeans that had sprouted in the pod pre-harvest. We may unfortunately see a lot more of this with additional rains.

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Removed a bunch of pods from a plant with Diaporthe/Phomopsis complex in which there were many flat, unfilled pods and pods of various stages of fill. This is what I found in the pods. This complex consists of diseases such as Pod and Stem Blight, Stem Canker, and Phomopsis Seed Decay. Perhaps note which varieties you notice more of this.

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Two different grain quality concerns in soybean. (Left photo) This soybean damage can be attributed to potentially a few things. I have found pycnidia of Phomopsis (Phomopsis seed decay) in samples like this. The UNL Plant and Pest Diagnostic Clinic has also diagnosed Phomopsis Seed Decay in samples. There’s also a publication from Ohio State (https://agcrops.osu.edu/newsletter/corn-newsletter/2017-24/stink-bugs-soybean) which attributes these symptoms to stink bugs. There was stink bug pressure in some fields this past year. So there’s potential that we have a few things occurring creating these symptoms. (Right photo) This soybean damage is called ‘Purple Seed Stain’ and is caused by the fungus Cercospora kikuchii. I mentioned this in this blog post.

Corn Observations

 

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Pre-harvest was seeing quite a bit of Fusarium in places where hail stones or insect damage occurred on ears such as this photo. Notice at the base of the ear, the ‘starburst’ shape occurring within kernels (I think of it like fireworks exploding when viewing the top of the kernel). Kernels infected with Fusarium will have a white/pink fungal growth that later causes kernels to become brown or gray and shriveled.

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This ear was from the same hail-damaged field as photo above and I picked this right before the field was harvested. The Fusarium and picnic beetles had greatly destroyed affected kernels. Cladosporium (green colored fungus) can also be seen affecting this ear where damage had occurred.

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.

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The deep red color on this hail damaged ear is due to Gibberella. We may see an increase in this with all this late-season rain. Other symptoms include matted fungal growth with husks sticking to ears. Gibberella has the potential to produce the mycotoxin zearalenone. The presence of the fungus DOES NOT automatically mean the presence of a mycotoxin.

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Kernels at harvest displaying damage from Fusarium and Gibberella. I received a number of samples from various farmers displaying these symptoms and picked out these kernels to show. Notice the pink/red discoloration of the kernel and also the shrunken, damaged kernels that are brown or gray in color. Grain should be dried as quickly as possible to 15% moisture to cease fungal growth in storage.

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This is another field I’ve been watching that was hail damaged. The ears themselves show very little damage; however, my concern is the ‘starburst’ pattern occurring throughout these ears throughout the field. The ‘starburst’ pattern is also characterized by the white lines observed on the sides of individual kernels. This is caused by Fusarium.

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The above photo is that same field at harvest. ‘Starburst’ pattern on kernels seen as white streaking due to Fusarium. More severely infected kernels are brown in color and dissecting them show they were trying to germinate. Also noticing cob rot occurring. Drying the grain to 15% moisture as quickly as possible will cease fungal growth. Fusarium also has the potential to produce the mycotoxins Fumonisin and Deoxynivalenol (also known as DON or Vomitoxin). NOTE: The presence of the fungus DOES NOT automatically mean the presence of a mycotoxin.

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.

Grain Storage

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.

Days required to dry corn to 15 percent moisture with 1.0 cfm per bu. UNL EC

“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.

Mycotoxin Information

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.

Fusarium sp. mycotoxins.PNG

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.

Table 2 expected detrimental feed concentrations of common fusarium mycotoxins-ISU

Source: Corn Ear Rots, Storage Molds, Mycotoxins, and Animal Health, Iowa State publication, 1997.

 

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.

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