Category Archives: Crop Updates
Harvest: Good to see harvest going and have heard some great bean yields! Also heard numerous reports of how hard it was to cut beans with green stems, bean stems falling over due to stem borer and winds, and beans running 9-11% moisture. There’s some chalky looking beans due to Diaporthe complex and purple seed stain was also observed in some varieties. Harvest safety is still the greatest priority. I don’t think I’ve heard of so many combine fires in one week as what we experienced last week in the U.S. and Canada, including several in Nebraska. Hopefully all the people were ok and the farmers can get going again somehow. Also, this past week was brutal driving with dust flying on gravel roads with sun glare at dusk. Lights on, stop at intersections and railroad crossings, please be safe!
Armyworms: Hopefully this is my last week talking about them! The questions have differed each week, so I share in hopes that it helps. We’ve just not seen these types of numbers for decades (from what I’m told). What has been interesting is hearing stories. One person who called me relayed a historical account of families and neighbors staying up all night driving up and down the roads squashing armyworms to keep them from crossing the roads into other fields. That’s dedication!
We put together a FAQ in CropWatch of common fall armyworm questions at: https://go.unl.edu/skx2. Last week the calls transitioned to pasture questions around products labeled for pastures with 0 day grazing restrictions with cattle present. Warrior II, Mustang Max, Beseige, Prevathon have 0 day grazing restrictions. You can see additional active ingredients, grazing, and haying restrictions at this website from Auburn Extension.
(Photo caption: armyworms in a pasture. You can typically find them in the edges between the brown/green. A lot of stress already in pastures due to drought. New growth observed shortly after insecticide application to kill the armyworms.)
Planting small grains and armyworms: I need to clarify from last week’s article that I didn’t mean to imply they needed to be seeded last week or immediately, just that they should still be seeded if that was in the plan. Ideally, yes, the sooner after harvest they’re seeded, the better establishment that typically occurs. But there are risks that one also needs to consider, such as the Hessian fly free date for wheat. For those who called, we discussed an option of a ‘wait and see’ approach where small grains for either grain or cover crop could still be planted in early October and still obtain good growth and establishment. Waiting after the Hessian fly free date (which occurs during various dates in late Sept. for Nebraska) and until the first full week of October may allow for enough cooler weather for the fall armyworms to head south and allow newly planted small grains to be established. We honestly don’t know when they will move south. Delaying till early October is one approach instead of trying to get small grains planted and being worried about scouting them for armyworms as they emerge while you’re also trying to harvest.
Cover Crop Seeding Rates for small grains (rye/wheat/triticale) is another question I’ve received. If seeding for erosion or even weed control, seeding rates of 20-35 lb/ac. are often fine. If you are receiving payment for EQIP or from another entity such as NRD or Pheasant’s Forever, they may specify the rate that needs to be seeded. For grazing, UNL typically says aim for a seeding rate of 60-70 lb/ac, but I’ve heard producers use anywhere from 40-80 lb/ac. Two publications with considerations for planting cover crops after corn or soybean can be found here: https://mccc.msu.edu/statesprovince/nebraska/.
Nebraska Extension Dean Interviews: If you’re interested, you can find information about the candidates here: https://ianr.unl.edu/dean-and-director-nebraska-extension. The public is invited to a meet and greet for the NE Extension Dean candidates on October 1, 6, and 8 from 5:30-7:30 p.m. at Raising Nebraska (state fairgrounds) in Grand Island. There is also a zoom link for these. If you’re interested in attending via zoom, please let me know and I’ll send you the links. At a time when Extension systems have been cut across the country and with systems in other states moving to regional instead of county-based models, it’s a critical time in Nebraska Extension’s history for the future of what Extension in Nebraska looks like. Would encourage you to attend and ask questions if you’re interested.
There’s times after I write this column on Sunday nights that I could turn around and write another one after Monday hits! Last week was one of those weeks, so here’s considerations for this week. Also, reminder to remove ET gages and irrigation scheduling equipment from fields before harvest.
Woolly Bear Caterpillars have been around since fair time at lower levels in landscapes and fields. However, they are showing up fairly heavy in later season soybeans right now, so it’s wise to be scouting for them. They’re doing a lot of leaf defoliation, yet also watch the pods for clipping or feeding on them. The economic threshold for defoliation is 20% in reproductive stages. I have been seeing them dying in fields from beneficial fungi as well, so look for dead/dying caterpillars and consider this as well. Decisions to treat are very field dependent. Organic options include various Bt products which impact caterpillars but don’t hurt other beneficial insects. Be aware of pre-harvest intervals (PHI) listed on the label (also pages 338-344 of 2021 Weed/Disease/Insect Guide); most products list 18+ days.
(Photo captions below): 3 woolly bears on this plant (left), lots of defoliation (top, right), and what dead woolly bears due to beneficial fungal pathogens look like (notice the duller color-they start almost looking a gray/white with age and don’t move).
Fall Armyworms: My phone went crazy again last week about them. Feel badly for all who had to reseed new alfalfa seedings, reseed cover crops, reseed small grains, and for all reseeding lawns. Their feeding happens so quickly. Even those who cut older stands of alfalfa were finding the armyworms weren’t killed after cutting. I was most commonly asked if cover crops or small grains should even be planted/replanted until the fall armyworms disappeared. Yes, they should as these small grains and covers obtain better establishment and growth the sooner they’re planted. The fall armyworms will eventually move south; however, entomologists don’t know the exact trigger for that. With the moths still flying, we may continue seeing larval feeding for a few weeks. What I told people who called or texted was to plant (being prepared with a product in mind should you need it), scout once the new seedlings start coming and be ready to apply a product if necessary. I listed a number of products in last week’s column, including organic options for consideration. Not every field nor lawn is impacted; it’s all dependent upon where the moths lay their eggs. A field or lawn that was impacted once may not be impacted again.
Harvest: Beans have dried down fast in spite of some green stems and leaves attached. Hearing moistures ranging from 10-14% on 2.0-2.5 maturity beans with yields depending on rain and disease. Even the corn is drier than what it appears inside some of these fields as I’m taking on-farm research notes. With harvest most likely ramping up this week, please be safe! It’s really dry which makes for dangerous road conditions and greater fire potential.
Harvesting soybeans as close to 13% is a goal for which to aim, in spite of the challenge. It’s perhaps a combination of art and luck depending on environmental conditions. Consider beginning harvest at 14% moisture making combine adjustments and operating at slower speeds as necessary. While there’s a dock of around 2.5% for the first 2 points delivering wet beans, delivering soybeans much below 13% moisture reduces profits because there’s fewer bushels to sell (load weight divided by 60 lbs/bu assuming 13% moisture). Selling soybeans at 8% moisture, you’re losing about 5.43% yield; at 9% moisture, it’s 4.4%; at 10% moisture, 3.3%; at 11% moisture, 2.25%; and at 12% moisture, it’s 1.14% yield loss. That doesn’t take into account additional risk for shatter losses during harvest. Only 4-5 beans on the ground can add up to a bushel/acre loss due to shatter. The following are profit examples:
Example 1. If the grower was to sell beans at 13.8% moisture, he/she would be docked 2.5% of the selling price of $12.30/bu, reducing the actual price to $11.99 per bushel. Total income per acre would be: 75 bu/ac yield x $11.99/bu = $899.25 per acre gross
Example 2. If the soybeans were harvested at 9% moisture, there would be 3.3 fewer bushels per acre to sell (4.4% of 75 bu/ac yield due to water loss): 75 bu/ac – 3.3 bu/ac =71.7 bu/ac yield x $12.30 = $881.91 per acre gross. In this example it’s better to take a dockage for selling beans at 13.8% moisture than sell them at 9%. The difference is a positive gain of $17.34 per acre or around $2341 on a 135 acre field.
Example 3. If the soybeans were harvested at 12% moisture, there would be 0.86 fewer bushels per acre to sell (1.14% of 75 bu/ac due to water loss): 75 bu/ac – 0.86 = 74.14 bu/ac yield X $12.30 = $911.92 per acre gross. If you can’t hit 13%, it’s still pretty profitable to sell them for 12% moisture compared to the other examples. Here’s wishing you a safe and profitable harvest!
Crop Update: The cooler weather and rains have been welcome here even though other parts of the State have had excess and flooding. I think grain fill has slowed down some in the corn, which will hopefully help. The rains will help the beans, milo, and pastures. If we can escape storms, early planted beans look pretty powerful this year! In a recent conversation with Dr. Jim Specht, he was sharing how he was anticipating really high bean yields. Upon asking him about that and also about the smoke/haze, he shared that he didn’t think it would have much impact on soybeans compared to corn. This is because soybeans are C3 crops where the photosystem saturates out at lower solar radiation levels; C4 crops like corn don’t, thus cloudy/hazy days have more impact on corn. The high humidity we’ve experienced has reduced transpiration of crops, allowing many non-irrigated soybeans to hang on till these August rains. As I’ve looked at crops in several counties, for the most part, it’s taken awhile for beans to start turning, even in the non-irrigated corners compared to what we typically see in dry years. Here’s hoping for some nice bean yields!
York Co. Corn Grower Plot Tour will be held this Thursday, September 9th from 5:30-7:00 p.m. at 1416 Road I, York, NE. Pizza and beverages will be provided. Attendees can guess the highest yield without going over for a chance to win a $50 gas card. We’re grateful to Ron and Brad Makovicka for hosting the plot and to all the companies represented in providing entries! We hope to see you there!
Wheat: I realize planting wheat is most likely not on many people’s radar in this part of the State. Yet, after attending the wheat and alfalfa expo today, just wanted to share a few thoughts and resources for those considering it. For those seeking resources, my colleague Nathan Mueller in Saline County has dedicated a section of his web page (http://croptechcafe.org/winterwheat/) to growing wheat in Eastern NE including an email listserv that shares new information. The website has a virtual variety tour where you can view varieties and their characteristics. A new tool on the website I learned about is a seeding rate calculator that helps in ensuring correct seeding rate based on the seed weight of the lot you receive. CropWatch also has its yearly ‘wheat edition’ in September, so be on the lookout for that this month at https://cropwatch.unl.edu and you can also check out https://cropwatch.unl.edu/wheat. Key points I emphasize for wheat include: killing out volunteer wheat in a mile radius at least 2 weeks prior to planting new wheat, treating wheat with fungicide seed treatment, and ensuring proper seeding depth by ensuring enough weight on the seeder particularly when no-till planting into residue.
I realize the economics for one year don’t look great for wheat. However, looking at the bigger picture, what is the value of that wheat crop in allowing additional time for a forage or cover crop, breaking pest cycles, and giving you an additional 2-3 months-time before needing to apply herbicides for weeds like palmer amaranth? What value does the residue provide for the following year to help reduce the number of weeds and/or in conserving soil moisture for the successive corn crop?
There’s also different ways of adding wheat into an operation. There’s some who have tried double cropping with both short season corn or soybeans after harvesting wheat. There’s also been interest regarding relay-cropping wheat and soybeans on Twitter. This past year, I had the opportunity to watch a few growers in the Archer/Chapman area try relay cropping wheat with soybeans on acres that were in seed corn the previous year. Their goals included using the small grain in wheat to aid in reducing palmer amaranth pressure and to obtain greater economic benefit from harvesting both a wheat and soybean crop. The Panhandle Research and Extension Center in Scottsbluff was doing the same with wheat and dry beans. There’s a lot we’re all learning in this arena and it’s just another way, with a lot more management challenges, to consider adding wheat in a crop rotation. Perhaps the biggest thing we learned was to have a high wheat seeding rate and proper fertility to allow the heads to be more uniform with less tillers that are short (similar to if one is raising a small grain for seed).
For those not desirous of planting wheat for grain, it can be used as a small grain cover crop for weed control as well. At two field days near Clay Center this summer, some individuals from Kansas and southern portions of Nebraska talked about how they recommend wheat or barley before a corn crop and rye before a soybean crop when considering a small grain cover crop for weed control. Their reasoning made a lot of sense. Wheat and barley don’t take off growing/greening up as fast as rye does. They also don’t obtain as much biomass (which also allows for faster nutrient cycling). They found farmers felt more comfortable planting corn green into wheat compared to rye for those reasons. I have no research or experience on that, but it makes sense and wanted to share if it’s something any of you would be interested in trying next year. In a soybean situation, I still recommend rye before the soybeans for weed control because of the increased biomass, and we’ll have data from Dr. Amit Jhala and his team this winter on that.
Crop Update: It was great to see people at soybean management field days last week and to hear their experiences around cover crops and weed management! White mold in soybean was the primary question received last week. It was already heavy in some Butler and Polk county fields and has since increased in York county with calls over the weekend. I don’t get too concerned about managing different insects/pathogens/weeds as we have various management strategies for them. White mold, though, is a very difficult one to manage.
It’s a soil-borne disease in which the fungus survives in a black structure (sclerotia) that resembles mouse droppings. Rain events and irrigation during flowering can favor it along with extended dew periods and fog like we’ve experienced this year. If you see random plants in an area that are turning brown but remaining upright, look into the canopy and see if there’s white cottony fungal growth on the stem. You may also see the black sclerotia on either the outside or inside of the stems. It can continue to spread from plant to plant. Management right now includes managing soil moisture and irrigation. It’s important to keep the top portion of the soil as dry as possible (which I realize is practically impossible with heavy dews). When it comes to irrigation management, infrequent, heavy watering is better than light, frequent watering in heavy-textured soils. It’s a good idea to keep notes on areas of the field you’re seeing it this year so you’re aware of it the next time soybeans are planted.
Some cultural and crop rotation things going forward that may or may not fit for your operation, yet good to be aware of: No-till allows the sclerotia to die more quickly on the soil surface (within 2-3 years), whereas tillage allows sclerotia that are buried to survive longer. Also, as we think of cover crops and crop rotations, fields with a history of white mold should avoid rotations for 2-3 years with edible beans, field peas or other pulses, canola, turnips, radishes, sunflowers, or potatoes. Grass crops (corn and sorghum) and using small grains like wheat, rye, oats, etc. in rotation can help reduce the amount of sclerotia that survive. For more detailed information, check out: https://soybeanresearchinfo.com/soybean-disease/white-mold/.
Watch insects in soybeans regarding clipping pods; not seeing too much of that yet. Am seeing bean leaf beetles and grasshoppers in several counties. Saw woolly bear and green cloverworms in Nuckolls co. last week. I have no idea why Japanese beetles are still around for all who keep asking!
Have been seeing sudden death syndrome (SDS) for several weeks now. For those seeing it in fields where beans were treated with ILeVO or Saltro, the symptoms can still appear on beans treated with those products. In spite of this, from our on-farm research fields that had a history of SDS, the symptoms were less in the treated beans than the check treatment.
Mid-August brings a sigh of relief to many agronomists in getting closer to the end. I’m sure our farmers will be grateful to get to the end of irrigation season this year too. Many soybeans are at R5-R5.5 (can see seed development in pods on upper 4 nodes). At this point, flowering stops. Soybeans at R5 still need around 6.5” of moisture to finish. At R6 (full seed), that amount drops to 3.5”. We don’t talk about last irrigation yet for corn at milk stage. For fields at dough (R4), corn needs around 7.5” of moisture yet to finish and 5” at beginning dent.
Seward County Ag Banquet to be Held August 23: The Kiwanis Club of Seward partnered with SCCDP and Seward Co. Ag. Society will honor Seward County Ag Leaders on Monday, August 23, 2021 with our 53rd Annual Agriculture Recognition Banquet. The banquet begins with wine, cheese, and sausage at 5:30 p.m. and a prime rib meal at 6:30 p.m. Ag Promoter, Educator, and YouTube Sensation, Greg Peterson will be the evening’s entertainment. This event provides an excellent opportunity to recognize the importance of agriculture in Seward County. The evening will honor the Seward County farmers, producers, ag businesses and ag students for their continued economic contributions to our strong local agricultural economy. Due to COVID not allowing us to have a banquet in 2020, we will be honoring individuals and families selected in 2020 and 2021. Please contact Pam Moravec, Banquet Chair, 402-643-7748, or Shelly Hansen, 402- 643-3636 information about becoming a banquet sponsor. The cost to attend the banquet is $30.00 per person. You can contact Pam or Shelly to reserve you seat. The Kiwanis Club of Seward will use the proceeds from the event to support the youth of Seward County through a variety of programs and events, including the Agronomy Academy.
Thank You to all the volunteers; ag society and 4-H council members; Extension staff; and all the youth and families who made the 2021 York and Seward County Fairs successful! It was a joy for me to see ‘normal’ fairs, youth and adults excited to find their projects and show their ribbons, the number of people out attending activities, walking through buildings, and just talking with each other!
Crop Update: Thanks also to the crop consultants and ag industry agronomists who dropped off samples during fair and kept me in the loop with what you were seeing in the fields! Southern rust was also confirmed in Hamilton and York counties this week. Frogeye leaf spot is also showing up on some soybeans with the high humidity and dew on soybean leaves.
Many have asked why the crops aren’t using much water. ET is evaporation from soil and leaf surface + transpiration (process of water lost through leaf stomata) from the crop. The high humidity has kept plants wet, especially soybeans, longer during the day (which is why I think the soil moisture use has been showing up less on soybeans than corn). I know many, including myself, have been trained that crops automatically remove 0.30”+ a day upon tassel and flowering, but that’s just not true. That thinking doesn’t account for the environmental factors at play which change every day of every year. Higher ET occurs on sunshiny days with high heat, higher wind, low humidity. Cloud cover, humidity, and low wind all reduce ET (and we’ve had a lot of these lately). As I’ve worked with farmers through the years, I’ve heard many say how helpful their ET gage was, because it’s such a visual representation of what’s going on with the environment and crop water use. If you don’t have an ET gage, the UBBNRD is sharing daily crop water use from the High Plains Regional Climate Center via email, so you can contact Marie there if you would like this info. each day. Thankfully, the humidity has allowed non-irrigated crops to hang on longer, due to lower crop water demand, in spite of the humidity being harder on us and animals.
Pollination: I realize there’s pockets of really good looking corn out there. And, I also realize that a lot of corn may look good from the road, but there’s concerns and questions about pollination and tip back in fields. As I think about when pollination occurred, the smell of pollen was thick in the air some mornings, and even early evenings when pollen shed was delayed from high humidity. Many fields I walked into had ample pollen shed. There’s a range of pollination dates in the area, so heat/humidity could have played a role for your specific fields. Dr. Tom Hoegemeyer shared the following about high heat and humidity during corn pollination in a CropWatch article, “Just a day or two difference in flowering, or planting, or other factors can make a substantial difference in (kernel) set. Stress during pollination and silking could result in shorter ears, increased tip back and fewer kernels per ear. All of these contribute to less yield potential.”
- When soil moisture is sufficient, one day of heat over 95-98F during pollination has little to no yield impact. After four consecutive days, there can be a 1% loss in yield for each day above that temperature. Greater yield loss potential occurs after the fifth or sixth day.
- Heat over 95°F depresses pollen production. Prolonged periods of heat can reduce pollen production and viability (ability of pollen to fertilize silks).
- High humidity helps reduce crop water demand. High humidity, without a drop in humidity during the day, can delay pollination or prevent pollen from leaving anther sacs. “The process of releasing the pollen from the anthers is called “dehiscence.” Dehiscence is triggered by the drop in humidity, as the temperature rises. However, when it is extremely humid and the humidity falls very little, dehiscence may not occur at all, or it may be delayed until late in the day. If one has breezes, while the humidity is still very high, the anthers may fall to the ground before pollen is released.”
I also think about what I’ve seen the past few weeks with all the silk balling, pollination misses, tip back, and what’s being shared with me by others in the field. The July 9 wind event that hit a portion of this area seems to have impacted plants more greatly that were within 1 week of tasseling. With the resources it took to right plants in developing additional brace roots, thickened nodes, etc., I wonder how much of the resources that would’ve been put into “normal” pollination were used for these other purposes instead and how that may have impacted pollination timing, silks pushed out of husks, etc.? A number of agronomists are reporting abnormal ear development they’re seeing in addition to pollination misses and tip back of various levels. This is what’s known from the research regarding wind impacts to yield on lodged plants (however the specific causes of the yield losses are not mentioned):
- Research found lodged plants after a wind event had yield reductions of 2-6% (V10-12 stage), 5-15% (V13-15 stage), and 12-31% (V17 and after stages).
- We’ve also personally observed yield losses greater than this due to abnormal ear development on lodged plants in the area after wind events.
Regarding tip back, it’s important to count kernels long as there may be more kernels than one realizes in spite of tip back occurring. Tip back on corn occurs most often from some sort of stress. One can tell the approximate timing of stress events by the appearance of the kernels. If kernel formation isn’t evident, the stress occurred before or during pollination. If kernels are very small or appeared to have died, the stress was after pollination as the kernels were filling. Japanese and rootworm beetle silk clipping can impact tip pollination. We’ve also had high heat with humidity since pollination in addition to cloudy/hazy days and I haven’t dug into the weather data yet. Hopefully this helps a little for the questions received thus far.
Reminder of the Seward and York County Fairs this week! August also brings the season of field days! Soybean Management Field Days will be held next week at various locations in the State from Aug. 10 to Aug. 13. The closest to this part of the State is Aug. 12th near Rising City at the Bart & Geoff Ruth Farm. More info. at: enrec.unl.edu/soydays.
Corn Update: I realize this week’s column shares lots of problems seen in the field last week. My goal is always to increase awareness, but sometimes it feels ‘heavy’ hearing about the problems. Grateful we’ve had few problems overall this season till now! The high humidity has allowed non-irrigated crops to hang on and crops in general to not use as much water as anticipated for crops at this stage. In general, fungal disease is still low in fields. I’m starting to see baby lesions that will most likely become gray leaf spot around mid-canopy, so that will be something to watch in coming weeks. Spidermites have also been flaring above the ear in some fields, particularly non-irrigated.
For our area of the State, southern rust has been confirmed in Adams, Nuckolls, Thayer, Gage, Saline, Clay, and Fillmore counties. There are probable samples at time of writing this for Seward and Jefferson counties (https://corn.ipmpipe.org/southerncornrust/). In all the samples, incidence and severity were very low. Many are being found around waist-high in the canopy. Three samples I confirmed last week were from fields that had already been sprayed and the pustules were found mid-canopy. This happens every year, regardless of the residual applied in the first application. I know a couple farmers who have paid a little extra to have the aerial applicator increase gallonage from 2 gal/ac to 3 gal/ac. They felt that aided in coverage a little further into the canopy. For those with chemigation certification, I also know several growers who chemigate their insecticide and/or fungicide effectively, which allows for better plant coverage into the canopy (as long as pivot doesn’t have drop nozzles below canopy).
I really enjoy observing what occurs with plants, yet I honestly don’t know anyone who wishes to see abnormal corn ears, especially after wind events such as July 9. I feel it’s important to observe and document what occurs on these plants that bent and didn’t break. The goal is awareness to know what type of ear development exists so there’s not such a surprise at harvest if yields are off, and to be aware when working with your crop insurance agent. There’s unfortunately some ugly looking ears out there. Some similar stress events occurred this year comparable to 2016, minus the drop in temperature prior to the wind event. I’m not seeing anything yet to the level like what we saw in 2016, which is encouraging. What I’m seeing ranges from row abortion above where the ear stress occurred to torpedo and banana shaped ears to pinched areas on ears including various forms of ‘barbells’. Finding greater damage in fields where the plants were within a week of tasseling when the wind event occurred. It also appears like those fields that were 2 weeks or more from tasseling at the time of the wind event aren’t as impacted. For growers that had plants that blew down or leaned and then righted themselves but didn’t break, it’s wise that you and/or your agronomist are checking ear development on them. Each field can be unique depending on stage of development the particular hybrid was in at the time of the wind event. Pictures of what is being observed are at jenreesources.com.
Soybean Update: Received a number of calls regarding poor-looking patches in soybean fields this week. Drought stress is showing up in non-irrigated fields. Be checking those areas for spidermites as well. If they’re present, I tend to find them towards the edge of the patch between the impacted area and what appears to be healthier beans. White mold in soybeans is something that’s becoming more common in counties such as Butler. It can have patterns such as several plants in a row impacted and/or a patchy area in the field. The plants will have a white cottony fungal growth on them and eventually the stem (upon splitting) has black fungal structures that look like mouse droppings in them.
Sudden death syndrome (SDS) and/or brown stem rot are also showing up in small patches of fields where the leaves have a chlorotic/necrotic look between the veins. The humidity has allowed the blue/gray fungal growth characteristic of SDS on the rotted taproots to be observed even mid-day. If you split the stem and the pith is brown, the culprit is most likely brown stem rot; if it’s not but the taproot is rotted and you can easily pull it from the soil, it’s probably SDS. Plants can sometimes have both diseases. All of these are soil-borne fungal diseases and there’s no control measures for this time of year. It would be wise to pull 0-8” soil samples to check for soybean cyst nematode in areas of fields you’re finding SDS and brown stem rot in. Dectes (soybean) stem borer tunneling can be confusing when determining dectes vs. brown stem rot. At this time of year, I don’t typically see dectes moving far (more than 1-2″ either direction) from the initial point of hatching near the petiole. This is in comparison to brown stem rot which would have browning of pith from soil line. Dectes also will not kill plants (just create conditions for lodging and breaking off near harvest). This is because the vascular bundles of soybeans are found on the outside edge and not in the center of the stem. Thus, death of plants this time of year are due to another cause.
Two examples of shortened husks on developing ears. Husking back these ears often shows a pinch point that occurred during the windstorm resulting in jumbled kernels.
Crop Update: Grateful that in general (beyond seed corn), greensnap levels were lower for the widespread area compared to what we saw in 2020. It appears many fields with leaned plants have been working to right themselves with brace roots growing like crazy to help stabilize plants. Ear development on bent plants will be something to watch going forward. With plants bending in the wind instead of breaking, sometimes extra stress occurs where the ear is developing. Sometimes we see ear abnormalities and sometimes the ears are fine. With fields with severe bending, once the plant reaches tassel, it will no longer try to right itself and will switch to putting resources into the ear. For those with storm damaged fields who were originally planning on more nitrogen through the pivot, last year we took tissue samples to assess that need.
For fields with uneven development with plants ranging from vegetative stages to tassel, particularly storm damaged and uneven emerging fields, one needs to be aware that various adjuvants added to an insecticide and/or fungicide application pre-tassel can cause ear abnormalities.
So, the conversation with those at western bean cutworm thresholds with only portions of fields tasseling was to consider not adding the adjuvant (the same applies for those applying fungicide). I wasn’t sure how efficacy would be for different products without them (that would be a conversation for the chemical reps), but we know that adjuvants such as non-ionic surfactants can cause ear abnormalities when applied pre-tassel.
Also had several conversations regarding foliar fungicide applications. Fields have very low disease pressure right now with bacterial leaf streak being the most prevalent, and a fungicide won’t help with it. Gray leaf spot is very low in fields. Southern rust has been found in a few counties in mid- to southern- Kansas. It has not been found in Nebraska. You can view the tracking map at: https://corn.ipmpipe.org/southerncornrust/. Yield increases with automatic VT applications aren’t consistently proven in Nebraska. The following are fungicide timing studies conducted in Nebraska.
In 2008-2009, a UNL fungicide timing trial was conducted near Clay Center on 2 hybrids (GLS ratings ‘fair’ and ‘(very) good’) with a high clearance applicator. Timing over the two years included: Tassel, Milk, Dough, 25%, 33%, 50%, and 100% Dent comparing the fungicides Headline, Headline AMP, Quilt and Stratego YLD.
- 2008: No yield difference on GLS hybrids rated ‘good’ at any of the timings (Tassel, Milk, 33% and 100% Dent) nor the check when Headline or Stratego YLD were applied. For the ‘fair’ hybrid, no yield difference for any application timing nor the check for the April 30th planting except for Headline applied at milk stage (increased yield). Low gray leaf spot pressure.
- 2009: No yield difference on GLS hybrids rated ‘very good’ or ‘fair’ nor the check on any timings (Tassel, Milk, and Dough) using Headline, Headline AMP, or Quilt. Moderate gray leaf spot disease pressure.
In 2020, Dr. Tamra Jackson-Ziems and her team did another fungicide timing trial at UNL’s South Central Ag Lab near Clay Center. Fungicides were applied at planting, R1, or R3. There were no clear yield differences between applying foliar fungicide at R1 vs. R3 for any of the products except Miravis® Neo. Sometimes a product didn’t show a difference between other products or even the untreated check. There’s a picture of the data at jenreesources.com. Hybrids vary in disease susceptibility (thus response to fungicide application). With last year being a heavy southern rust year, being able to wait till at least R3 (milk) to apply a fungicide provided some additional time for the residual to work when southern really came on. I know some had to apply a second fungicide application when they automatically applied at R1. That’s just tough from an economic and resistance management perspective, in spite of higher corn prices. Thus, why I recommend waiting until disease pressure warrants the application. The main ‘plant health’ benefit observed in Nebraska when disease pressure was low (ex. 2012) was stalk strength.
July 28 South Central Ag Lab Field Day will be held from 8:45 a.m.-4 p.m. (Reg. 8:30 a.m.), near Clay Center. For all those who’ve talked with me about planting green into rye, there’s an excellent study by Dr. Amit Jhala and grad student Trey Stephens. They compare the same herbicide program with rye termination 2 weeks prior to planting or 2 weeks after planting in both corn and soybean. It was really interesting to visualize the differences in May and I’d encourage anyone interested to take a look at this now in July. Additional topics include disease, insect, and nutrient management, cover crops, and irrigation. You can RSVP at https://enrec.unl.edu/2021scalfieldday
Crops really look tremendous overall and got a report of some first tassels by July 4th as well! It’s been great to see people attending field days again the past few weeks and really appreciated the learning, sharing, discussion, and just watching people catch up with each other at them. I had mentioned before how the lack of freeze/thaw was impeding roots of crops, particularly soybeans in no-till fields. Irrigating and rain has helped them get some growth. What I hadn’t mentioned in my articles was being called to soybean fields with HPPD (Group 27) carryover from corn herbicides in 2020. We had a dry fall but had rain in March and May, so I wasn’t sure how to explain the carryover. One thing I learned last week from a discussion at the palmer amaranth field day was that the lack of freeze/thaw also impacts the ability of herbicides to breakdown. So, I appreciated learning that and am sharing if that helps anyone else as well.
Japanese beetles are also heavy in pockets of the area. I will share more specifics next week. For those who are asking, the threshold for soybean defoliation in reproductive stages is 20%. Tom Hunt, UNL entomologist shared that pyrethroids in general are effective. However, if there’s potential for flaring spidermites due to dry conditions, bifenthrin is a consideration as it has activity for spidermites (particularly when considering soybeans). For homeowners, beetles can be dislodged off of plants right now in evening hours by knocking them into buckets of dishsoap water. Do not use pheromone traps as they will actually attract beetles to your yard!
Western Bean Cutworm: With crops nearing tassel, it’s time to be scouting for western bean cutworm moths and egg masses. There was a CropWatch article posted this week at: https://go.unl.edu/9v4a. It was predicting 5% moth flight for York on June 30th, Harvard July 2nd, and Central City July 3. I received a text from a crop consultant saying he found the first eggmass in the Central City area July 2, so that was pretty well on target! Twenty-five percent of WBC flight occurs when 2,577 degree-days Fahrenheit are reached. Entomologists recommend field scouting should occur at this point. For 25% moth flight, it’s predicting York on July 6th, Harvard area July 8th, and Central City July 9th, so we should start watching fields for sure this week. Look for egg masses laid on the upper surfaces of corn leaves, typically on the top 1/3 of the plant.
Chiggers: I should’ve written about this last week as chigger bites tend to peak around the 4th of July with more families outdoors. Chiggers (also known as redbugs or jiggers) are the immature stages of red harvest mites. They tend to hang out in moist, tall grassy/weedy areas such as along streams, road-side ditches, forested areas, lawns. But they can also hang out in moist and dry lawns with a lot of trees too. They bite humans and other animals including pets. Eggs are laid on clusters on plants and the larvae hatch and wait for their host to come along. They latch onto clothing, shoes, and fur and can hang on while working their way to the skin (often to an area where clothing is tighter like around socks, undergarments, back of knees and under armpits). They actually don’t burrow into human flesh. They only survive on a warm-blooded host for around 3 days before falling off to molt for the next stage in life cycle which doesn’t feed on humans.
They have needle-like mouthparts that allow them to pierce the skin then inject saliva that dissolves body cells in the area to aid them in feeding. Thus, they don’t feed on blood but liquefied cells. The feeding creates an allergic reaction in which many see swelling, intense itching, and small, clustered, red bumps (which can become larger welts in some). To prevent chigger bites, avoid sitting or lying on the ground when picnicking or working outdoors. Wear loose-fitting clothing and apply a repellent like DEET to shoes, socks, and pants before going into areas more favorable for chiggers. It’s also wise to take a hot shower with plenty of soap as soon as possible after being outdoors and launder clothing with hot water before re-wearing. Also launder any blankets/sheets being used outdoors. If you receive bites, rubbing alcohol can be used then apply an anti-itch cream to help reduce itching. Thankfully chiggers can’t live in the home but they can become dislodged in bedding and on floors, so laundering bedding and vacuuming is also wise. Keep lawns and shrubs well-manicured, particularly where adjacent to dwellings. If you tend to have problems with chiggers in your lawn, they can be reduced from 75-95% for several weeks with a liquid treatment of bifenthrin. Be sure to read and follow all label instructions.
Corn observations: It seems amazing to me to be where we’re at with harvest and it’s only October 4th as I write this! Many farmers finished beans last week and started on corn. It’s a good feeling to be at this point; can also appreciate there’s been no rain and not a lot of breaks either. Please be safe!
This past week was spent taking corn notes and starting to harvest corn studies. Besides harvest stand counts, I also like to look at percent stalk rot in fields. This gives an idea regarding standability and harvest priority. To do this, I use a pinch test using my thumb and first finger to pinch the elongated first or second internode above the soil line on 20 plants in an area of the field. Stalks that are compromised will “give” or “crush”. Obtain a percentage for the number of stalks that do so. Quickly doing this in five areas of the field provides a better idea of stalk health and harvest priority. Stalk quality pinch test video at: https://youtu.be/7z75VN1c51Q. So far, much of the corn is standing well. I’m mostly finding compromised stalks on plants that had premature ear droop. It will be especially important to assess stalk rot for fields that had high southern rust pressure and weren’t sprayed with a fungicide.
Another observation is some weakened ear shanks, although I can’t say this is a problem yet or even widespread. Weakened shanks makes sense on ears that prematurely drooped as that ear shank collapsed. Things we know cause weakened ear shanks and ear drop include stresses like high heat and/or moisture stress around pollination, large ears after this type of stress due to long grain fill, fungal disease like Fusarium infecting the shank, and to an extent, genetics (regarding shank diameter size). As we think of this year, we had the July 8th wind storm shortly before tassel which caused additional stress on plants. Corn also had a long fill period creating larger ears. So again, not saying this is a problem, just something to watch.
Stress cracks and broken kernels are another thing to watch for and seek to minimize. We know this can occur during the grain drying process in the bin when high moisture corn is dried with high heat followed by rapid cooling. In one conversation this week, a farm family was wondering if there were conditions that led to more stress cracks to corn in the field this year. I really don’t know. Found one publication that said internal, invisible stress cracks can also occur during kernel fill as a result of high temperatures and/or high moisture. However, the focus of the publication was viewing cracks with other types of imagery instead of the physiology, so I don’t have more to share on that. Broken kernels can also occur with harvesting higher moisture corn (above 20%), particularly with too high of rotor speed. A handful of guys have mentioned seeing broken kernels as they’ve been harvesting above 20% and shared the combine adjustments they’ve made to minimize them, so thought it may be something to mention. Combine setup is not my expertise but with a quick search, there’s a number of YouTube videos and websites regarding reducing broken kernels that may be helpful.
Corn Drydown Calculator: If you’ve never seen it or used it before, Iowa State University has a neat tool that estimates corn drydown in the field based on weather forecast for a particular area. It’s called the corn drydown calculator and you can find it at: https://crops.extension.iastate.edu/facts/corn-drydown-calculator.
Land Leasing for Solar Development Oct. 9th: Just a reminder of this virtual seminar to be held October 9th from 11 a.m. to 1 p.m. You can register at https://go.unl.edu/solarleasing. This seminar is open to the public. Farmers, landowners, and their families in areas with potential solar development have much to consider and should consider attending. This webinar will give an overview of solar development and touch on major issues to consider when negotiating a solar lease agreement. More info. on this topic at: https://cropwatch.unl.edu/2020/considerations-leasing-land-solar-development.
Soybeans: The past week I was mostly in soybean fields taking harvest notes for on-farm research or helping harvest plots. The non-irrigated yields have been better than anticipated for the beans just dying in fields; I can’t help but wonder what they could’ve been had there been rain in August! As noted last week, there’s a definite difference in varieties as to the number of 4-bean pods. Some varieties are loaded with pods and it’s not hard to find 4 bean pods. Others in our variety studies have a majority of 3 bean pods and it’s rare to see 4 bean ones. It will be interesting to see yields, and may be something to observe in varieties on your farms if you’re curious. Will also take a look at solar radiation data as several commented the smoke seems to be impacting drydown of irrigated soybeans.
Woolly Bear Caterpillars are noticeable in soybean fields as are stink bugs and loopers; however, woolly bears are also on the move from soybean fields to find green plant tissue elsewhere. In past years, it’s not uncommon to find them crossing roads. I had a couple of reports towards the end of last week of them demolishing garden plants and shrubs. They probably don’t need controlled in all cases and not all products are as effective on them. Bifenthrin is labeled to be effective on them and can be used on a variety of plants, so that may be one option if treatment is necessary.
Stalk Nitrate Test: A corn stalk nitrate test can provide an indication if the amount of nitrogen for the corn plants was low, high, or sufficient for that year. This test involves taking an 8” sample of the stalk. It should be taken 6” above the soil line and go to 14” above the soil surface. All leaf sheaths should be removed from the stalk. 15 samples should be collected 1-3 weeks after black layer from a one acre area that represents a larger area (same soil type, etc.). Sample other areas of the field with different soil types or management. Then place stalk samples into a paper bag (don’t use plastic) and ship the samples within one day or refrigerate until shipping. It’s important to take the sample from 6-14” above the soil line because all the research to create the test was done from that area of the stalks. Also note that situations like a good grain fill season, drought, or poor ear development can all impact the test providing lower or higher numbers. This test isn’t to be used to determine nitrogen rates. It just gives a ballpark over time regarding if too much, too little or sufficient nitrogen is available on a consistent basis over years in a field. If the test results over several years are consistently high (greater than 2000 ppm), it would suggest the grower could reduce nitrate rates without impacting yields. If too low, the grower could consider additional nitrogen or adjust nitrogen management within the field. You can read more about this test here: https://store.extension.iastate.edu/product/Use-of-the-End-of-Season-Corn-Stalk-Nitrate-Test-in-Iowa-Corn-Production. My colleague, Aaron Nygren, also created a short Twitter video here: https://twitter.com/ColfaxCountyExt/status/1305982739791966208?s=20.
Sensors and ET gages: A quick reminder to remove any sensors for irrigation scheduling and ET gages from your fields before harvest. In the midst of everything else, it can be easy to forget about them!
Fall Lawn Fertilization: Early September is one of the best times to fertilize Kentucky bluegrass and tall fescue. There’s still time to apply if it’s not yet been done. One application may be all that’s needed on older lawns (10 to 15 or more years). Use a fertilizer with at least a 50% slow release nitrogen source. Two fertilizer applications are recommended on younger lawns; one in late August/ early September and one about mid-October. Use a slow release nitrogen source on the first application and a fast release nitrogen source on the second one. Avoid fertilization after late October as plant uptake is low. This causes nutrients to leach away during winter or linger in soil until spring leading to early growth. More info: How to Fertilize Turfgrass This Fall.