Monthly Archives: September 2020
Bean harvest was rolling this week. Hearing non-irrigated beans in the area ranging from 40-60 bu/ac and irrigated beans going 70-90+. Regarding solar radiation and some wondering about smoke impact on drydown, I ran data from 9/1/20 though 9/26/20 for Harvard and York weather stations. Then looked at long term average for this same September time-frame from 1996-2020. Both stations showed slightly higher solar radiation in 2020 compared to the long-term average for September (York: 379 and 372 langleys respectively) (Harvard: 383 and 376 langleys respectively). And, it was higher yet for 2020 when I queried Sept. 10-26 for same time periods. So, unsure solar radiation was the factor impacting drydown for this part of the State?
Small Grains and Weed Control: Been watching weed control particularly in soybean fields. For future columns/winter programs, I’d like to hear from you. What weed control approaches have worked in your soybean and corn fields? I’m curious about all systems and all types of weed control options. Please share at email@example.com or give me a call at the Extension Office. Thanks!
In the past, I’ve shared weed control begins at harvest by not combining patches of weeds or endrows full of weeds. I realize that’s difficult to do, and for many fields, we’re past this point. From a system’s perspective, another option to aid weed control is to plant a small grain such as wheat, rye or triticale this fall. We had a whole edition of CropWatch devoted to wheat production here: https://cropwatch.unl.edu/2020/september-4-2020. Wheat provides an option for both grazing and grain. Rye provides the best option for earliest green-up/growth in the spring and longest seeding time as it can be seeded into December. Triticale provides the most biomass but produces the latest into late May/early June. All keep the ground covered from light interception penetrating the soil surface which allows weed seeds to germinate. While I’ve observed this in farmers’ fields, there’s also recent research from K-State that supports the impact of a small grain in rotation for weed control.
One study looked at marestail (horseweed) and palmer amaranth control from 2014-2015 in no-till soybeans at six locations in eastern Kansas. They also found the majority of marestail emerged in the fall (research from UNL showed up to 95% does). They compared five cover crop treatments including: no cover; fall-sown winter wheat; spring-sown oat; pea; and mixture of oat and pea. Cover crops were terminated in May with glyphosate and 2,4-D alone or with residual herbicides of flumioxazin + pyroxasulfone (Fierce). Ten weeks post-termination, palmer amaranth biomass was 98% less in winter wheat and 91% less in spring oat compared to no cover crop.
Another study in Manhattan from 2015-2016 compared fall-seeded rye; a residual tank-mix of glyphosate, dicamba, chlorimuron-ethyl, tribenuron-methyl, and AMS; and no fall application. Four spring treatments included no spring application or three herbicide tank mixes: glyphosate, dicamba, and AMS alone or with flumioxazin + pyroxasulfone (Fierce) as early preplant, or as split applied with 2/3 preplant and 1/3 at soybean planting. They found the fall rye completely suppressed marestail while fall herbicide suppressed biomass by 93% and density by 86% compared to no fall application. They also found rye to reduce total weed biomass (including palmer amaranth) by 97% or more across all spring applications. In both studies, soybean yields were best with the combination of cover crop + herbicides or the combination of fall + spring herbicides compared to no cover and no herbicides.
The way I think about this for conventional systems is that the use of a small grain in the system reduces the pressure on the chemicals for having to provide all the control. It also buys some time for chemical control, perhaps even removing one application (based on these studies, small grain delayed at least a month till 50% palmer germination). Economically, while there’s the expense of seeding and purchasing the small grain seed, what are the other economics to consider? What could the small grain provide by reducing an additional chemical application, adding a forage crop after harvest, selling seed (if there’s a market), selling straw (depending on location for moisture savings & ability to get a cover back in for weed control), etc.? Just some considerations this fall looking at weed control by adding a small grain.
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.
Will miss catching up with people at Husker Harvest Days this week! Virtual field day at: https://www.huskerharvestdays.com/en/home.html.
Grateful for the rain! It provided a break, the end of irrigation, and will help with settling dust and hopefully reducing fire risk. Here’s wishing you a safe harvest as it resumes! May see some soybean shatter. Was hearing reports of soybean moisture ranging from 9-11% over Labor Day weekend on 2.0-2.5 maturity beans. Saw non-irrigated soybean fields in Nuckolls/Webster county area that died with the leaves still attached. The previous week’s heat with the lack of moisture for so long was just too much.
One area on-farm research study is a soybean maturity study. This is the third year for this study and after harvest we’ll have 9 site-years worth of data. The objective is to determine yield and economic impacts from planting 2.0-2.5 maturity beans vs. 3.0-3.5 maturity beans in April to early May. Planting a range of maturity groups can aid in spreading out harvest; we’ve found about 1 day delay for every 0.1 in maturity group. Planting a variety of maturity groups can spread risk regarding timing that heat and moisture (or lack of) are received (especially for non-irrigated beans). There’s also increased interest in earlier maturing varieties for seeding a cover crop for erosion and/or weed control or increased biomass for grazing. Our data thus far has found genetics to be the bigger yield factor as there’s high yielding genetics regardless of 2.0 to 3.5 maturing varieties.
The soybean yield equation is more complicated than determining yield for corn with final yield harder to predict. This is what it looks like followed by an example with numbers that Dr. Jim Specht shared:
[Plants/Acre X Nodes/Plant X Pods/Node X Seeds/Pod] / [Seeds/Pound X Pounds/Bushel] = Bushels/Acre
120,000 x 21 x 2 x 2.4 / [ 2500 X 60 ] = 81
Plants per acre is often less instrumental for yield as it’s inversely related to total number of seeds per plant (high population=less seeds/plant, low pop=more). We had more soybeans planted early in the area this year than I’ve ever before experienced. Early planting allows for increased nodes per plant. This year many remarked on plants being loaded with flowers; this could be partly due to the abundant sunshine. On average, Dr. Specht assumes 2 pods/node; there’s some nodes loaded with pods this year and we need to watch how they finish filling. A soybean pod contains, on average, 2.4 seeds, primarily because the 1-seed, 2-seed, 3-seed, and 4-seed pods produced by indeterminate soybean plants tend to occur in respective proportions of 10%, 40%, 50%, and ~0.1%. These proportions can vary somewhat among varieties.
As we think about the soybean yield equation, seed size (seed mass) is the component most impacted by lack of August rain or ending soybean irrigation too soon. This ranges from small (3750) to large (2250) seed/pound with most varieties today averaging about 2500 seed/pound. Last week’s rains will most likely help group three soybeans with seed size and reducing additional seed abortion.
Soybean Quality Study: The Nebraska Soybean Board and some researchers from UNL are asking farmers to help with a soybean quality study. I have sample jars in my office and all that’s required from you is to take 3 samples from a non-irrigated field and 3 samples from an irrigated field (not field corners). They will share results with the growers who participate. Please contact me at firstname.lastname@example.org or 402-440-4739 if you’re interested in participating!
Overseeding Lawns can still occur as late-August through mid-September is the best time to seed bluegrass and fescue. Fescue really shouldn’t be seeded any later than this but bluegrass can be into later September if needed. It’s really important to get good seed to soil contact by preparing the seedbed. The following publications from Nebraska Extension provide step-by-step instructions: Improving Turf in Fall and Establishing Lawns from Seed. Buy blue tag certified seed from a reputable dealer.
Explore Beekeeping free webinar will be held on September 24th from 6-8 PM. The speaker will address how she uses bees on her family farms in conjunction with pollinator cover crops and fruit trees. This program will be offered in English and Spanish. Participants can register online at https://go.unl.edu/beekeeping.
Emerald Ash Borer Found in Seward County
The Nebraska Department of Agriculture (NDA) confirmed Emerald Ash Borer (EAB) was found in a trap at the Blue Valley Campground in Seward, NE in early August 2020. This article will share information from Elizabeth Killinger, Extension Horticulture Educator, about what this means for your ash trees and what you should be doing now.
“Finding borer holes in ash trees doesn’t necessarily mean you have EAB. There are several different types of borers that attack ash trees, so correct identification is key. There are several different native borers that are normally found on ash trees. The ash/lilac borer, banded ash clearwing and carpenter worm can attack healthy ash trees. The redheaded ash borer, banded ash borer, flatheaded apple tree borer and eastern ash bark beetle attack stressed or dying ash trees. Knowing exactly which insect is in your tree will let you know if you should start looking for a replacement or if you need to treat.
EAB is an invasive beetle that attacks and kills all species of ash. It is a small, metallic-green beetle that is about 1/2 inch long. The larvae of this wood-boring insect tunnel under the bark of ash trees, disrupting the flow of water and nutrients, ultimately causing the tree to die. EAB infested ash trees will exhibit thinning or dying branches in the top of the tree, S-shaped larval galleries under bark, D-shaped exit holes and suckers or advantageous growth along the trunk and main branches.
Proper tree identification is key to knowing if you should be concerned about EAB or not. The bark of ash trees have diamond shapes or capital “A’s”. Ash trees have an opposite leaf pattern, or the buds are across from one another on the stem. They also have leaves of 5 to 7 leaflets. If you are lucky enough to get the seeded variety, the seeds look like paddle-shaped helicopters and are held in clusters on the tree. Ash trees, those in the Fraxinus genus, can include the green, white, Patmore, Marshall’s Seedless, and Autumn Purple Ash. Mountain Ash is not affected because it isn’t a true ash.
If your tree has EAB-like symptoms, like canopy thinning, branch dieback, sprouting growth from the base of the tree, or D-shaped exit holes, it should be examined by a professional. Leave your ash trees in as long as they are healthy, in good condition, and in a good location. If your tree is dying or diseased, it may be best to hire a certified arborist to look at your trees and determine the cause of the decline.
Because of the cost, treatments are only recommended for high value and/or already healthy trees. Once EAB has been confirmed within the 15 mile radius of your location, then you can begin the proper treatment applications on healthy trees. Depending on the size of the tree, a soil drench is one option for homeowners. The drench can be applied to trees with under a 20” diameter trunk yearly throughout the lifespan of that tree. Tree care professionals are able to use additional products like trunk injections on larger trees. Contact a certified arborist for these treatments. Some products are best applied in the spring, while others can be done throughout the summer. We don’t recommend treatments this fall.
Ash has been a popular landscape and conservation tree for a long time due to its fast growing nature and overall appearance. Diversity in the landscape is important to the overall health of the community forest. Aim to have diversity and try not to have any one species make up more than 10% of the landscape. A diverse landscape isn’t as affected by single outbreak. Now is an excellent time to start thinking about replacement trees for ash. For a list of replacement trees visit The Nebraska Forest Service list of replacement trees or Trees for Western Nebraska (PDF). More information about the emerald ash borer, finding an arborist, and recommendations can be found at https://nfs.unl.edu/nebraska-eab.”
Harvest: Harvest has begun for some with soybeans, seed corn, and silage. For all of us as we’re on the roads, please be alert and slow down. It’s also important to talk about safety with teens who drive. With it being so dry, gravel roads are extra dusty, reducing visibility. It can be helpful to turn on headlights and be sure to slow down at intersections. On highways, slow down when coming upon slow-moving equipment. And, be aware of equipment turning. Here’s wishing everyone a safe harvest!
Nebraska Public Power District, Rural Radio, Center for Ag Safety and Health, and Nebraska Extension are teaming up to share on harvest safety with the Harvest Safety Tour. Power line, ATV, and grain bin safety demos will be on display and a free lunch will be served September 9th from 11 a.m.-1 p.m. at the big parking lot at the York County Fairgrounds. For more information call 877-ASK-NPPD.
Early and mid-group two soybeans rapidly turned last week and may be drier than one realizes in spite of having green stems. Every year it’s a challenge to harvest close to 13% moisture. There’s a dock for delivering wet beans. While not a dock, delivering soybeans 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. The following are two profit examples:
Example 1: Based on the elevator dockage numbers obtained, if the grower was to sell beans at 13.8% moisture, he/she would be docked 3% of the selling price of $8.75/bu, reducing the actual price to $8.49 per bushel. Total income per acre would be: 75 bu/ac yield x $8.49/bu = $636.75 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 $8.75 = $627.38 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 $9.37 per acre or almost $1265 on a 135 acre field.
Harvesting at 13% moisture is perhaps a combination of art and luck depending on environmental conditions. Some tips to achieve this can include begin harvesting at 14% moisture, making combine adjustments and operating at slower speeds (consider these equipment adjustment tips for your combine), plan variety selection to spread out maturity and harvest (we’re finding around 1 day delay for every 0.1 difference in maturity group), and avoid harvest losses from shatter as only 4-5 beans on the ground can add up to a bushel per acre loss.
Pasture & Forage Minute: With Dr. Bruce Anderson’s retirement (former Extension Forage Specialist), a team of Extension specialists and educators are sharing pasture and forage minutes. These quick updates are also shared via email. If you’re interested in receiving them, you can sign up for the email list by going to this site: https://listserv.unl.edu/signup-anon , enter PASTURE-AND-FORAGE under ‘list name’, and your email.
Emerald Ash Borer (EAB) was found in Seward in a trap at the Blue Valley Campground in early August. We don’t recommend treatments right now in the fall. Because of the cost, treatments are only recommended for high value and/or already healthy trees. Once EAB has been confirmed within the 15 mile radius of your location, then you can begin the proper treatment applications on healthy trees. A yearly soil drench application is one option for homeowners for trees under a 20” trunk diameter. Tree care professionals are able to use additional products like trunk injections on larger trees. Contact a certified arborist for these treatments. Some products are best applied in the spring, while others can be done throughout the summer. Treatment zone considerations can be found here: https://nfs.unl.edu/documents/EABmap_2020-08-03.png. Please don’t move firewood to help prevent the spread!