Monthly Archives: August 2021
Congratulations to all the 4-H youth who competed at the Nebraska State Fair this past weekend! The talent of our youth never ceases to amaze me. It’s also so encouraging to see life skills being developed such as public speaking, plant and insect identification, and the responsibility and care for animals.
Also so grateful to receive rain last night! And, that should finish up irrigation, or get it pretty close, for many that didn’t have late-planted crops. It’s really important to know your crop growth stage and to finish well. There’s some fields that are obviously over-irrigated with water standing after this last rain. On the flip side, it’s important to monitor soil moisture and crop growth stages to not stop too soon in spite of the long irrigation season and how tired farmers are. Several questions last week on ‘how’ to finish with irrigations and when physiological maturity occurs in soybeans.
Last irrigation: if you’ve been triggering irrigation during the growing season based on the recommended 35% depletion (average of 90 kpa on watermark sensors), you would have around 1.28” of moisture available in the top 4 feet for the plant in silt loam soils. A consideration for a step-wise approach I’ve used is this: Corn at ½ milk line needs around 13 days or 2.25” to finish the crop to maturity-so subtracting that from 1.28 would be 0.97”. As we consider allowing the soil moisture profile to deplete to 50-60% for recharge over the winter, a person could delay to 40-45% depletion (around 130 kpa average on watermarks) before triggering irrigation the first 7 days and then allow for 50% depletion (around 150 kpa average on watermarks) that last 7 days to finish irrigation for corn.
Soybeans range from full seed (R6 end of seed enlargement) which needs 18 days or 3.5” of water; R6.5 (leaves yellowing/pod membranes still clinging to seed) which needs 10 days or 1.9” yet; or physiological maturity in which the pod membrane has separated from the seed and no more water is needed. The NebGuide, “Predicting the Last Irrigation of the Season”, speaks to yellowing leaves as the beginning of physiological maturity. But the question I kept getting last week was “how yellow is considered yellowing leaves?”. Perhaps a better indicator for today’s varieties would be to also look at the pods. Until the pods reach R7, physiological maturity, the plant is still utilizing water. At R7, at least 50% of the field plants will have one mature pod anywhere on the main stem. A mature pod is considered when the pod membrane no longer clings tightly to seeds in that pod (this is like black layer on corn where the nutrient/water supply is cut off from the kernel forming the black layer). So essentially, if you pull off a pod on the main stem, carefully open it up and look at the membrane surrounding the seed. If it’s still clinging tightly to it, it’s not quite mature. If you see separation of the membrane and seed, it’s considered mature and will no longer use water. There can be a range of pod stages on a plant, but between yellowing leaves and pod color changes, one can get a pretty good idea when R7 has occurred and no additional water is needed for the plants. The timing of the ending R stages in soybean is determined by planting date and varietal maturity group, though the date of R7 can be hastened if water stress and high temperatures prevail in August — something we are seeing this year.
Soybean stems typically turn brown shortly after R7 begins, though the stem can remain green longer due to a number of reasons, including fungicide use. The final soybean stage is R8, which occurs when 95% of pods have attained maturity and have a variety-dependent color of brown or tan. Seed moisture in a soybean pod dries down from 70% at R7 to about 13% at R8. This has shown to be around 12 days based on research, but can be faster or slower depending on solar radiation, humidity, temperature, wind speed and soil surface moisture.
So, for scheduling last irrigation in beans: if we use the same example of having 1.28” of available water at 35% depletion in silt loam soils in top four feet, soybeans would need 2.22” with 18 days to finish at R6 or 0.62” with 10 days to finish at R6.5. Using the stepwise approach, one could again allow the soil moisture to dry down to 40-45% the first week and 50-60% the second week. This also allows room to catch rain like we finally experienced last night.
Fall armyworms have been on the increase in alfalfa and pastures recently, so please be scouting as they can decimate a field quickly in the late larval stages. The threshold is 3 or more per square foot and they’re easier to control if the larvae are ¾ inch long or less. When they’re larger than this, they’re more difficult to control and choosing to harvest the alfalfa may be a better control method. Insecticide options include products with active ingredients including the pyrethroids, Alpha-cypermethrin (Fastac CS), Beta-cyfluthrin (Baythroid XL), cyfluthrin (Tombstone), Gamma-cyhalothrin (Proaxis, Declare), Lambda-cyhalothrin (numerous products), permethrin and Zeta-cypermethrin (Mustang Max), organophosphates, chloropyrifos (numerous products), and carbamates, carbaryl (Sevin) and methomyl (Lannate).
Crop Update: The heat has really pushed crops along. Grateful for the reports of some rain! It’s really important to know your soil moisture levels and work for the balance of not stopping too soon vs. leaving the field too wet going into the fall/winter. The following information comes from the NebGuide: Predicting the Last Irrigation of the Season found at: https://go.unl.edu/k74n:
- Corn at Dough needs 7.5” (approximately 34 days to maturity)
- Corn at Beginning Dent needs 5” of water (approximately 24 days to maturity)
- Corn at ¼ milk needs 3.75” (approximately 19 days to maturity)
- Corn at ½ milk (Full Dent) needs 2.25” (approximately 13 days to maturity)
- Soybean at beginning seed (R5) needs around 6.5” (approx. 29 days to maturity)
- Soybean at full seed (R6) needs 3.5” (approx. 18 days to maturity)
- Soybean with leaves beginning to yellow (R6.5) needs 1.9” (approx. 10 days to maturity)
Alfalfa and Wheat Expo: Southeast Nebraska farmers can sharpen their management strategies at the inaugural 2021 Southeast Nebraska Alfalfa and Wheat Expo. The inaugural Alfalfa and Wheat Expo is scheduled for Thursday, September 2, 2021, in Crete at the Tuxedo Park Exhibition Building. The Expo will begin at 8:00 a.m. with refreshments and exhibitor booths. The educational program starts at 9:00 a.m. and ends at 3:30 p.m. Hosts and local Water & Integrating Cropping Systems Extension Educators, Nathan Mueller, Gary Lesoing, and Melissa Bartels said more diverse crop rotations are both underutilized and undervalued. Integrating alfalfa and winter wheat into the crop rotation can provide a critical tool to mitigate extreme weather, improve soil health, increase corn and soybean yields, combat troublesome pests, increase flexibility in manure management plans, and more. This new expo will help farmers prepare to grow these crops for the first time or fine-tune the skills of experienced alfalfa and winter wheat growers. Speakers and panelists will address important issues for southeast Nebraska farmers and allow for great one-on-one discussion with local private industry exhibitors and sponsors. The Expo is free to attend including lunch, but pre-registration is requested by August 31. For more info. and to pre-register, please visit https://croptechcafe.org/alfalfawheatexpo or call the Saline County Extension office at 402-821-2151.
Renovating Lawns in the Fall: August 15-September 15 are the best times to seed cool season grasses. This resource, Improving Turf in the Fall at https://go.unl.edu/rz9z is a great one to walk you through renovation depending on your situation. Some lawns can be easily improved by adding fertilizer this fall.
Sarah Browning, Extension Horticultural Educator shares, “Late summer or fall fertilization of Kentucky bluegrass and tall fescue lawns is the most important time to fertilize these cool season grasses. Fertilizer applied now promotes recovery from summer stress, increases density of thinned turf, encourages root and rhizome growth, and allows the plant to store food for next spring’s growth flush. On older lawns, those that are 10 to 15 or more years old, that typically need only two fertilizer applications a year, make the fall application in late August or early September using fertilizer with all or some slow-release nitrogen. On younger lawns, two fertilizer applications during fall are recommended. Make the first one in late August or early September, and the second in mid to late October. For the first one, select a fertilizer with all or some slow-release nitrogen. For the later application, use a fast release nitrogen source so plants will take it up before going dormant.”
Other lawns can be improved via overseeding or total renovation. If overseeding is needed to fill in thinned areas but more than 50% of good turf remains, mow the existing grass 2.5” tall to make the soil preparation easier. For lawns needing total renovation, start with a glyphosate (Roundup application) followed by waiting at least 7-10 days to kill the lawn. Mow dead vegetation as short as mower goes to then prepare the soil for planting.
To prepare the soil for seeding, it’s helpful to aerate the lawn making three passes. Watering a day or two beforehand can make the aerification easier. The full seeding rate for turf-type tall fescue is 6-8 lbs./1,000 sq.ft., and 2-3 lbs. for Kentucky bluegrass. When overseeding into an existing lawn, the seeding rate can be cut in half. Drilling the seed is perhaps easiest for a total lawn renovation. Otherwise, use a drop seeder to apply the seed (not rotary ones as the seed is too light to spread evenly). Make sure to seed half the seed north/south and the other half east/west to ensure even distribution. Then lightly rake in the seed to ensure seed to soil contact. Starter fertilizer is helpful for new seedings where the total phosphorus is 1 to 1.5 lbs/1000 sq. feet. It’s also important to keep the top ½ to 1” of soil moist as seedlings germinate. Thus, it may requiring watering several times a day the first two weeks, depending on temperature and moisture. As seedlings develop, reduce the watering schedule to allow root development. When the grass is tall enough to mow, reduce watering to only 2-3 times/week with deeper watering. Mowing as soon as the grass allows encourages tiller development and thicker new stands.
God, I’m so grateful that we can come before Your throne to receive mercy and find grace to help in time of need. My heart is so broken for the situation in Afghanistan…I’ve struggled for words. The news…the photos and video footage…all just glimpses into the horrible truth that lies there. I’m just so grateful when there’s nothing else I can do that I can come to You in prayer for this situation.
Please God, be extra close to the women, children, all those individuals who helped our military, all those who converted to Christianity, all those who may in the future, all the Americans trapped there. I can’t imagine what they’re all going through…can’t imagine what they’re facing and fearing…Please help them to know You can be their refuge and strength, helper and deliverer in the midst of all the turmoil. Help them to experience Your love, peace, comfort in this midst of this storm. Please be with all those helping with evacuations, all the pilots in the rescue efforts and the trauma they must be facing and living with, all their families who are supporting them…I just don’t have words…as I cry out with tears, I just can’t imagine this entire situation. Please God, raise up leaders in Afghanistan willing to fight for their country to take it back. Thank You God for being a God who knows, sees, hears!
And God, my heart goes out to all our military members and their families…the sacrifices made, the prices paid, all those still serving there aiding in evacuations. So many different experiences and perspectives. Please God, be with them all. Help each one, especially now, not to isolate, but to reach out and talk to someone. Help them to find peace in their purpose even now. And please God, protect our military members who will be the last out whenever that occurs.
God, I don’t understand Your sovereignty yet I’m so grateful You’re in control and I’m not. I’m so grateful Jesus already defeated death and the grave and will one day reign victorious! Please let me…let all who put our hope and trust in You rest in that hope…for that’s the true hope we have in the midst of so much brokenness on this earth. I’m so grateful You allowed me to live in the U.S…so blessed to live in this Country…broken, but still the greatest nation in the world. Please God, heal our land and divided nation. Please be with all our Government leaders, help them seek Your face and give them wisdom and discernment. Please continue to be with our military and their families.
Thank You God for how You’re working…in the ways we can and cannot see. Thank You for the comfort You provide when I come to You in pouring my heart out to You! I thank You for all this and pray this in Jesus’ name, Amen.8/16/21. Updated as I continue to pray. Shared in the event it could help anyone else and for those who’ve asked for thoughts. Ultimately, we can pray and we can reach out to veterans and their families to see if they would like to talk.
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.