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Drought-Maintaining Silage Quality
Unfortunately the drought continues to intensify. All Nebraska counties have now been released for haying and grazing of Conservation Reserve Program (CRP) lands. Information and resources continue to be added to UNL Extension’s Drought Resource page at http://droughtresources.unl.edu. Please check it out for drought information for livestock, crops, water, and gardening.
Some have started chopping corn for silage or are about to soon. Dr. Bruce Anderson, UNL Extension Forage Specialist, shares the following information about maintaining silage quality in the future. “After silage has been chopped and piled and packed correctly, it still can be damaged seriously by air and moisture slowly penetrating the outer 3 to 4 feet. Animals often eat less when fed moldy silage and can even experience health problems due to mycotoxins.
Good, well-eared silage can lose over 20% percent of its feed value from fermentation and spoilage under normal conditions. Silage made from corn with little or no grain might have even greater losses. This loss can be cut in half or even more if the silage is kept well covered by plastic.
Cover freshly chopped silage with black plastic immediately after you finish filling the trench, bunker, or pile. Then cover the plastic with something to help hold it down. Old tires are readily available and do a good job of keeping the plastic from blowing away, but they only keep keep pressure on the silage directly under the tire. In between the tires, air can circulate and cause spoilage.
An even better choice would be a solid cover over the plastic, something like freshly chopped forage or weeds or maybe even a 3- to 4-inch layer of manure. This would ensure that the entire surface of silage is fully protected to reduce the chance for air bubbles to form under the plastic which could reduce silage quality. You go to a lot of time and expense to make good silage. Isn’t it worth it to protect that investment?”
Southern vs. Common Rust in #Corn
In early July, southern rust caused by the fungal pathogen Puccinia polysora was discovered in Hall, Adams, Clay, Fillmore, 
Thayer, and Burt counties in Nebraska. Most farmers in south-central Nebraska remember the corn season in 2006 walking out of fields orange and the slow harvest due to downed stalks. Since then, southern rust has been a disease of concern and fungicides are used to prevent and also treat it when it’s found in fields.
I promised when we were first discovering southern rust this year that I’d post pics, so while delayed, here they are! It is often confused with common rust which we see earlier every year. Common rust typically has pustules (raised fungal spores) that are brick red in color, larger, and on the upper and lower leaf 
surfaces. The pustules tend to be more spread out.
Southern rust typically has very small pustules that are clustered on predominately the upper leaf surface and are tan to orange in color. This year, southern rust pustules tend to be more tan in color than orange but are still distinctively different with their smaller and clustered appearance. Both fungal rust pathogens arrive in Nebraska each year via wind from the south. Southern rust prefers warm, moist conditions which, in spite of our dry spell, is typical within our pivot and gravity-irrigated fields in the area. At this time we are recommending if you find southern rust in your field to consider treating with a fungicide. Please be sure to read and follow all label directions including paying attention to pre-harvest intervals. A list of corn fungicides and efficacy can be found here by scrolling down to the corn section.
Additional information and pictures of these diseases can be found here.
Drought: Resources & Options for Corn
Well, the heat isn’t letting up. Sixty-nine Nebraska counties are allowed to hay and graze Conservation Reserve Program (CRP) lands. In our area these counties include: Hamilton, Hall, Webster, Nuckolls, and Thayer. From Teri Post at the Webster Co. FSA office, this means that: “If it (CRP) is hayed, it cannot be sold and cost to the livestock person cannot exceed the 10% reduction on contract payment. Paperwork MUST be completed prior to anything being done. If you do not have livestock but do have a CRP contract, you can lease your acres to a livestock producer. They have also released CP25 (wildflower mix) for grazing only. If you prefer to sell the hay and you qualify for managed haying, you may do that but you will be assessed a 25% payment reduction rather than the 10% with emergency release. Also keep in mind that use of emergency haying or grazing restarts the time clock for when you can hay or graze next. If you use the emergency hay or graze release, even if you hayed or grazed in a prior year you are now eligible to hay or graze again.”
Nebraska Farmers who have drought damaged corn which could be swathed and baled, chopped, or grazed can list that on the Nebraska Hay and Forage Hotline. The hotline is available free of charge for buyers and sellers to list feed resources. Call the hotline at 1-800-422-6692 to list the forage you have or to list your need for forage. I’ve been contacted by Extension 
UNL Extension has developed a Drought Resource Web resource that pertains to crop and livestock producers. Some of you have been asking about options for dryland crops right now. Research has shown benefits to the following crop if stubble height is left at least 10 inches tall when haying or cutting silage from drought damaged corn fields. Leaving a higher stubble height will also reduce the nitrate levels in the forage that has been cut.
When it comes to your options on what to do with weather-damaged corn, Dr. Bruce Anderson, UNL Extension Forage Specialist and Tom Dorn, UNL Extension Educator, recommend to consider the following points before harvesting your crop as forage:
- If grain prices remain high, grain yield may not need to be very high to justify selecting grain harvest over forage harvest.
- Sometimes leaving the corn residue can result in increased yield next year and that increase may provide more value than that resulting from forage use. See NebGuide G1846, Harvesting Crop Residues for information on evaluating your situation.
- Check labels of all chemicals applied to be sure they are cleared for forage use and that the minimum harvest interval has been met.
- Check with the USDA Farm Service Agency and your crop insurer to maintain compliance with farm programs and crop insurance requirements.
- Nitrate concentrations can reach toxic levels in weather-damaged corn. The harvest method can affect the nitrate, a particular concern when its being fed to livestock. Leaving a tall stubble (8 or more inches) will reduce nitrate risk but note eliminate it. Choose the harvest method accordingly.
Silage may be the safest method of harvest as fermentation usually (but not always) reduces nitrate levels and risk. Yield is about one ton per acre of silage for each harvested foot of earless corn plant (not counting the tassel). Feeding value is about 70% to 80% of well-eared corn silage. Corn with some grain (less than 50 bushels) tends to produce about one ton of silage for every five bushels of grain with a feed value about 80 to 90% of regular corn silage.
Harvest timing is critical with silage to ensure the correct moisture for proper fermentation. Plants probably are about 80% moisture now and the desired moisture level for silage is about 65%. Plants with any green leaves usually are too wet to chop for silage. For proper moisture, most leaves may need to be dead before chopping. The stalk and ear hold amazingly high water concentrations. For corn with no grain, even if all leaves are dead, the whole plant (and silage) moisture can be 70% if the stalk is still green and alive. Once plants actually die they can rapidly dry down. There are several ways to reduce moisture content:
- If corn has pollinated, delay silage harvest until all chances of increased biomass tonnage have passed or plants naturally dry down to appropriate moisture levels.
- Corn can be windrowed and allowed to partially dry before chopping.
- Excessively wet material can be blended with drier feeds such as ground hay, cracked grain, or dried distillers grains. However, this can take a lot of material — about 500 lb of grain or hay to reduce each ton of chopped corn with 85% moisture down to 70% moisture.
- Silage inoculants may improve fermentation and preservation of drought-damaged silage.
Green Chop: Green chop minimizes waste but may be the most dangerous way to salvage corn. If present, nitrates will start to change into nitrites (about 10 times as deadly) as green chop begins to heat. Chop and immediately feed only an amount that animals will clean up in one feeding. Chop and feed two or three times per day instead of providing excess feed from a single chopping. If any green chop remains two hours after feeding, clean out bunks. Never feed green chop held overnight because nitrites can be exceptionally high. Be sure to allow plenty of bunk space (36 inches per cow is recommended) so boss cows don’t overeat and timid cows can get their share.
Hay: Hay may be the most difficult method of mechanical harvest, especially if ears have started to form – the stalk and especially the ears will be slow and difficult to dry. If possible, use a crimper when windrowing. Unlike with silage, nitrate levels do not decrease in hay after it is baled. Some of the nitrate risk can be reduced by cutting to leave a tall stubble, about 8 inches. Tall stubble also will elevate the windrow off the ground, allowing air to circulate better through the forage and aid in drying.
Grazing: Challenges with grazing include acidosis risk for cattle not accustomed to grain if ears have started to fill (smart cows will selectively graze ears), waste from excessive trampling, availability of drinking water, perimeter fencing, and nitrates. Reduce acidosis risk by feeding increasing amounts of grain similar to feedlot step-up rations before turning into standing corn that has much ear development.
Reduce waste by strip-grazing with at least two or three moves per week; daily is best. Back fences are not needed because regrowth is not expected. Water can be hauled in as with winter corn stalks or lanes might be constructed with electric fence to guide animals back to water sites that are nearby. If strip grazing, animals can walk back over previously grazed areas since back fences aren’t needed.
Perimeter fences can be built using the same fencing as for winter stalks. Cows are likely to respect such fencing but inexperienced calves may not remain where desired. To better control calves, use a double strand of electric wire and/or a more visible barrier such as electric polyrope or polytape. Animals not already experienced with electric fences may need some exposure and training before moving them to a corn field.
Nitrates usually are not a problem with grazing since the highest concentration is in the stem base, the plant part least likely to be consumed. Risk increases, though, if animals are forced to “clean-up” a strip before moving to fresh feed and when corn plants are short (probably less than 3 to 4 feet tall) with small, palatable stem bases. Tests for nitrate concentration (whole plant and just the bottom 8 inches of the stem base) can be made prior to grazing to assess risk. If nitrate levels are risky, the hazard can be reduced by offering enough desirable forage to discourage consumption of hazardous plant parts as a major component of diet. Also, delaying grazing until plants more fully mature often lowers nitrate risk. NebGuide G1865, The Use and Pricing of Drought-Stressed Corn, offers additional information.
Windrow Grazing: This method includes cutting as you would for hay and then grazing the windrows rather than baling them. It eliminates the cost of baling, transporting bales, feeding bales, and maybe hauling manure. It also eliminates any flexibility in feeding location and may reduce opportunities to sell the corn forage.
Windrowing tends to preserve forage quality better than allowing plants to stand. Usually it is easier to strip graze windrows than standing corn because building fences and estimating strip size are easier. Snow cover rarely causes problems if animals already know the windrows are there. They will use their hooves and face to push snow aside to access the windrow. Thick ice, however, can cause a significant barrier. Follow appropriate management recommendations listed earlier for hay and grazing for best utilization and safety.
Additional Resources: US Drought Monitor Map and High Plains Drought Monitor Map
Crop Water Use Comparison Study
Water use efficiency (or crop water productivity) is important in crop production. The seed Industry has invested scientific 
efforts and financial resources into developing hybrids and varieties that can better tolerate environmental stresses such as water stress.
Rainfed corn has increased in acres, replacing sorghum year after year. This trend may be partly due to the basis price, herbicide options, and newer corn hybrids bred with root systems to better withstand water stress. In 2009 the question was posed, “Is sorghum still the most crop-water-use-efficient crop, given newer corn hybrids in rainfed fields are providing decent yields and more herbicide options?” To answer the question the Nebraska Grain Sorghum Board funded a project in south-central Nebraska.
On-farm research was conducted for three years in rainfed production fields near Lawrence with the most adapted and high-yielding corn, sorghum, and soybean hybrids and varieties for that area. The research was conducted in no-till fields where the previous crop had been sorghum. A randomized complete block design with three replications was used.
Corn and soybean were planted between May 5 and May 7; sorghum planting ranged from May 19 to May 28. Corn was planted at 20,000 seeds/acre, soybean at 135,000, and sorghum at 65,000. Rainfall in this area varied greatly from 2009 to 2011: 2009 was dry with only 10 inches of rain during the growing season; 2010 had 16 inches, and 2011 had 20.5 inches from May 1 to October 15.
To monitor soil moisture, Watermark sensors were placed at 1-, 2-, 3-, and 4-foot depths in each plot and the readings were 
recorded hourly throughout the growing season via Watermark dataloggers. Data were compiled and analyzed to determine crop water use efficiency (CWUE) values. The CWUE values were determined from the Watermark soil moisture data, actual crop water use (evapotranspiration), and grain yield for each crop.
Results: Table 1 shows actual crop evapotranspiration (ET) in inches, grain yield, and crop water use efficiency for each crop in each year. Corn was the most water use efficient of the three in 2009. Sorghum results in 2009 might have been different if rainfall had occurred to activate the sorghum herbicide as grass pressure was heavy in the sorghum plots that dry year. In 2010-2011, sorghum yielded the most, had good weed control, and had the best crop water use efficiency value.
| Table 1. Crop water use efficiencies in on-farm field trials conducted near Lawrence, Nebraska, 2009-2011. | |||||||||
| 2011 ET (in) |
2011 Yield (bu/ac) |
2011 CWUE (bu/in) |
2010 ET (in) |
2010 Yield (bu/ac) |
2010 CWUE (bu/in) |
2009 ET (in) |
2009 Yield (bu/ac) |
2009 CWUE (bu/in) |
|
| Corn | 22.0 | 127.2 | 5.8 | 23.3 | 101.2 | 4.3 | 14.5 | 97.5 | 6.7 |
| Soybean | 21.3 | 61.3 | 2.9 | 22.0 | 44.0 | 2.0 | 14 | 33.4 | 2.4 |
| Sorghum | 17.3 | 138.9 | 8.0 | 21.3 | 118.0 | 5.5 | 13.7 | 77.4 | 5.6 |
Overall in this study, sorghum had a crop water use efficiency of at least 5.5 bu/inch; corn, at least 4.3 bu/inch, and soybean, at
least 2.0 bu/inch. These results show sorghum’s continued value as a crop that efficiently uses water. Sorghum produced more grain per unit of water used than corn or soybean, an important benefit in water-limited environments. On a three-year average, sorghum resulted in 1.2 bu/inch and 3.5 bu/inch more grain production per inch of water used than corn and soybean, respectively. This study did not compare sorghum or soybean with new “drought-tolerant” corn hybrids. Graphs, charts, and production information can be found here.
Acknowledgements: Special thanks to John Dolnicek of Lawrence, Nebraska for allowing this research to be conducted on his farm and for all his help and efforts to make it a successful study and to the Nebraska Grain Sorghum Board for funding this study.
Soil Crusting in #Soybeans Causing Concerns
On May 6, quite a storm was unleashed in south central Nebraska. Soybeans that had been planted two to three days before the
storm seem to have emerged fine, while those planted May 5-6 tend to have uneven emergence and crusting. This is occurring regardless of tillage type, residue cover, etc. Many farmers have been running pivots to help the soybeans break through the ½- to 2-inch crust, often applying an inch of water before they see stand improvements.
The primary question for growers has been “Should I replant?”
UNL on-farm research has shown less than 1.4-2.0 bu/ac yield difference between planting 90,000 and 180,000 seeds/acre. (See report.) In our research, 90% of the planted stand was achieved at both seeding rates in irrigated 30-inch rows in no-till and ridge-till fields.
Consider what was found in 2006 in one dryland field in Nuckolls County where populations of 100,000, 130,000, and 160,000 seeds/acre were planted. This field was at the cotyledon stage when it was hailed. Some plant stands dropped to 67,000. Yield was 4 bu/ac less than in the 160,000 seed/acre planting that had a final stand of nearly 98,000. The average yield in the field was 40 bu/ac. While this is only one field and one year of research, it is an example of how soybean plants can compensate for reduced populations by branching and how August rains in dryland can still allow reasonable yields to be produced.
UNL research conducted by Dr. Jim Specht, UNL Soybean Physiologist, also has shown that for every day planting is delayed after May 1, there is the potential to lose 1/4 to 5/8 bushel per day. As we near the end of May and early June and consider that late planting yield penalty and the dry soil conditions (particularly in dryland fields), along with the seeding rate results from this UNL on-farm research, we are recommending that growers leave stands in many fields. Based on our on-farm research, leaving dryland stands of at least 65,000 plants/acre and irrigated stands of 90,000 plants/acre is likely a better choice than replanting.
We realize that there are some larger gaps in various rows in the field, and while we don’t like to see that, the gaps are disappearing as plants continue to grow and branch out. Keep in mind that a gap in one plant row will be compensated by plants in the adjacent flanking rows. They will form extra branches to take advantage of the sunlight, thus single-row gaps may not be as yield-reducing as you might think — especially in 15-inch row spacings.
We’re also seeing how resilient soybeans are. Some soybeans have been in the ground for two weeks and in many cases, are fairly healthy below the crust. Soybean seedlings emerge by pulling (not pushing) their cotyledons upward. The seedlings rely on the cotyledons as a reserve source of carbohydrate, protein, and lipid to support early seedling development until leaflets open for photosynthesis. When a seedling tries to pull its cotyledons through a crack in the crust, the crack may be too small and the cotyledons may be stripped off.
The plumule, which is the seedling stem tip and its undeveloped leaves above the cotyledonary node, may remain, but 
without the cotyledons to serve as a carbon and nitrogen source, development of new seedlings with small leaflets will be slow. These plants may not become competitive with surrounding plants in terms of pod and seed production. Therefore, when counting seedlings to determine plant stand after a soil crusting event, count only the seedlings that have at least one cotyledon. You can count seedlings missing cotyledons if they have large unifoliolate leaves that will soon unroll such as the picture on this page.
Recommendation: When deciding whether to replant your field, consider UNL research findings that showed a minimal yield difference between stands of 90,000 and 180,000 seeds/acre. We recommend leaving irrigated soybean plant stands of 90,000 or more and dryland plant stands of 65,000 or more. Uniformity of plant stands is also important, but “patch” planting may be used to deal with local areas of low plant stands.
For more information on reduced soybean planting rates, see the April 20, 2012 CropWatch story, Drop Soybean Seeding Rate and Save $10-$18 per Acre.
Future of Rural America
Sunsets over rolling hills of green pastures and straight corn rows. Barely seeing above soybeans I was walking to remove 
weeds. Attending a small school that provided an excellent education with opportunities to participate in a variety of activities to become more well-rounded. These are a few of numerous memories of growing up on the farm and in a rural community that I hold dear. While I enjoy hearing my grandparent’s stories of what life was like for them farming 60 years ago and even enjoy watching the Nebraska State Cornhusking Contests held each year, I also realize times have changed and don’t have a false sense of nostalgia about what rural means today. While technological advances allow our farmers to produce more food for more people with less inputs and less water than ever before, what hasn’t changed about rural communities is the hard work ethic, dedication, risk, determination, and reliance on Faith and family to get through each year.
Last week I had the opportunity to participate in the Rural Futures Conference held in Lincoln. For me, it was the best conference I’ve attended; the energy and enthusiasm from 450 people gathering from a variety of backgrounds all to discuss the future of rural America was refreshing to say the least. My favorite part of the conference was the first evening. The key note speaker Joel Sartore, a Nebraska native who is also a National Geographic photographer, challenged us to maintain a positive attitude and to look for the opportunities that were available in our small towns. For example, one town in Kansas was all about a certain sparrow where they would take people out on field trips to “listen”-they didn’t even get to “see” the sparrow-and people paid money for that! There was also a town in Oklahoma where all they had was rattlesnakes…so they made the most of that too and created a huge attraction around snake handling, pics with snakes, snake skinning, etc.
My favorite part of the conference occurred after that during the youth panel. A panel discussion with Caleb Pollard, 
Executive Director of Valley Co. Economic Development in Ord, NE; Amanda Crook, Graduate Student; Anne Trumble, Executive Director of Emerging Terrain in Omaha; Jim McClurg, University of Nebraska Board of Regents; and University of Nebraska Med Center’s Bob Bartee answered questions moderated by Dr. Ronnie Green, IANR Vice Chancellor. The young people struck a chord with me-most likely cause we were of similar age. Some key take-away quotes:
- Vibrant organizations identify strong leadership.
- Failure can be a good thing as it can lead to the next innovation.
- To go some place and change the trajectory of history is exciting!
- We need to change the way we place young people into jobs….we don’t offer young people jobs; we offer them opportunities.
These young people were so excited about living in Nebraska! Some of them had spent time elsewhere before choosing to move back to Nebraska and eventually choosing to find a small town to raise their families or have the rural way of life. Another theme that emerged throughout the conference was the need to get young people involved in the local community such as youth representatives on city council, etc. even as early as when they’re in high school. Some people think small town communities in Nebraska are dead…but that’s not necessarily the case. It mostly depends on leadership-a strong leader will rally the town around an idea to grow it or create opportunities. That’s what’s happening in Ord, NE with Caleb Pollard. Another example comes from Fairfield Iowa. Sometimes it just takes the right person to ignite a spark and help the rest of the town see the possibilities. Nebraska has so much to offer!
Frans Johansson, author of The Medici Effect, was also a phenomenal speaker! He spoke about creating breakthrough innovations by thinking outside the box and working at intersections of different disciplines/cultures, etc. Key points I obtained from him include:
- New ideas are combinations of existing ideas.
- People who change the world try FAR more ideas.
- Diverse teams can unleash an explosion of new ideas.
- Find inspiration from fields/cultures other than our own.
- Look for the smallest executable step-essentially don’t eat the elephant in one bite.
- Stepping into intersections isn’t risky-it’s risky to do the same thing over and over again.
Maybe these aren’t earth-shattering new concepts, but good reminders for a task as large as creating a Rural Futures Institute…and frankly for anything in life.
There was much discussion about the role of a University/State/Community Colleges in trying to save rural communities…how is this done…how build partnerships and trust…how to provide incentives to faculty working in creative/innovative ways in a structured academic setting when it comes to promotion and tenure…and even if the University changed its incentives, how does that bode if a faculty member moved on to another University? How are incentives provided to teams and excellent team work? We are standing at the crossroads…maybe an intersection right now in academia which can shape the future of creatively rewarding innovative work while still maintaining needed structure in the promotion/tenure process. I remain positive that we’ll find a way to work through this!
There were discussions in small groups regarding the meaning of rural. What does it entail? Often we think of agriculture-and I would argue that’s a strong part of rural-but it’s also much more…health care, infrastructure, industry, schools, broadband, etc. Some were saying we need to use the term non-metro instead of rural in order to get away from the ag connotation. Yet others felt the discussion was too focused away from agriculture on other components of rural and missing ag as a key component. Needless to say, the entire conference provided interesting discussion, dialogue, and a chance to meet people from a variety of backgrounds. It truly provided an opportunity to look for intersections with which to create innovative ideas for the future.
There was also the reality that hit during focused group conversations that there are also problems that need to be addressed in rural communities that weren’t touched on at this point: poverty; crime; infrastructure; food deserts; building trust and interfacing with university, college, and other partners, etc. Overall it was a thought-provoking conference and has the feel that several small steps can be achieved in the coming year. I would encourage you to check out the Web page and follow the Facebook page. You can also check out the Twitter Conversation at #RFC2012. This conference was also not just focused on Nebraska as the focus was the Great Plains and people from numerous states attended. I’m looking forward to seeing the small executable steps that will occur in the future and am also looking forward to doing my part to maintain strong rural communities as I’d like to see the next generation enjoy the rural life and learn the values I did growing up!
The Season for #ag & #horticulture Questions!
This past week was a blur of calls, questions, and visits to homes and fields but it was a great week and flew by staying very busy! I’ll touch on a few of the common questions I’ve received this week.
Trees: Some trees such as willows, hackberries, tops of maple trees, ash, and black walnut are just taking time leafing out. Some trees leafed out once already and dropped leaves. Things that may have caused this were the sudden flux of temperatures from very warm to cool and the strong winds we received. Some trees have also unfortunately had herbicide drift damage that caused leaves to drop. On those trees, watch for new buds as nearly every situation I’ve looked at thus far have new buds forming after about a week-10 days. With all these situations, give the trees a few weeks to leaf out again and if they’re still not doing it, feel free to give me a call. Trees are interesting plants as sometimes environmental impacts that happened 3-5 years ago will show up that much later-and sometimes environmental impacts show up right away!
Disease/Insect issues: This year has been a strange year all around but with our warm winter, I was concerned about an increase in diseases and insects. Thus far, we’re experiencing increases in both-so hang on-it may be a long growing season! Our high humidity, warm temps, and heavy dews have created perfect conditions for fungal diseases on our trees, ornamental plants, lawns (I’m currently fighting a bad case of powdery mildew-as a plant pathologist it is kind of pretty but I don’t like what it’s doing to my lawn!), and in our wheat and alfalfa crops and some pasture grasses. Fungicides may help in some of these situations, increasing airflow can also help as can more resistant varieties or hoping the weather will change. In the case of most ornamentals, we don’t usually recommend doing anything. The same goes for insects as insecticides can help in some situations. I’ve received several calls this past week of people afraid they had herbicide drift damage. While there were a few cases of that, many of the cases were actually fungal leaf spots on leaves. There are various fungicides and insecticide products available from home/garden centers, etc. Be sure to read and follow all label directions and only apply the product on places the label specifies it can be applied.
Crops Update: Later this week we may have a better idea on the extent of storm damage and if some fields will need to be 
replanted after the storms from last week. Dr. Bob Nielsen from Purdue University reported that most agronomists believe young corn can survive up to about four days of ponding if temperatures are relatively cool (mid-60’s F or cooler); fewer days if temperatures are warm (mid-70’s F or warmer). Soil oxygen is depleted within about 48 hours of saturation and we know soil oxygen is important for the root system and all the plant’s life functions. So we’ll have to wait and see what happens.
Have also had a few calls regarding rye cover crops. When rye is killed out and decomposing, it releases toxins that can affect the germination of other cereal crops such as corn if it’s going to be planted into that rye cover crop. Thus we recommend at UNL that the producer kill the rye and then wait at least two weeks to prevent any major damage to the crop. I realize at this point with the rains to get in and kill that crop on top of waiting an additional two weeks, we’re getting close to the end of the month and will most likely be looking at reduced yields…and depending on maturity, you may need to consider different seed if you end up having to plant in June. If you have specific questions about this, please let me know and we can talk through some situations.
Stripe rust and powdery mildew have been obliterating mid-lower canopies of many wheat fields. I’ve received several calls
on why wheat canopies are yellow-that’s the main reason but other factors such as the dry spell prior to these rains and/or deficiencies in nitrogen/sulfur or some viruses may also have been factors. Wheat in Nuckolls County last week was beginning to flower. Fungicides such as Prosaro, Folicur, or Proline are labeled for up to 50% flowering and cannot be applied after that. Remember the wheat head begins pollination in the middle-so if you’re seeing little yellow anthers at the top or bottom of that head, you’re towards the end of flowering. All those products have a 30 day pre-harvest interval-which has been the other main question-are we going to be harvesting in a month? I do believe we’ll be harvesting a month earlier than normal just because pretty much everything in wheat development is about a month ahead of schedule. I still feel the 30 day window for the fungicide application is worth it with the large amount of disease pressure we’ve seen. Wheat in Clay Co. and north still may have time for a fungicide application; those products mentioned above will help prevent Fusarium Head Blight (scab) as well as kill the fungi causing disease already present on your leaves. A list of all fungicide products, pre-harvest restrictions, and rates can be found here. Also check out my previous blog post with video on scouting for wheat diseases.
The other major disease appearing in wheat is barley yellow dwarf virus. This is a virus vectored by bird cherry oat aphids which we were seeing earlier this year. Unfortunately, this disease causes the flag leaves to turn bright yellow-purple causing yield loss (at least 80% of the yield comes from the flag leaf) as there’s nothing you can do once the virus manifests itself in those leaves. If you have a large incidence of barley yellow dwarf in your fields, you may wish to reconsider spraying a fungicide as the fungicide won’t kill the virus; however, it will help kill the fungi on the remainder of your leaves and potentially help protect some yield from the two leaves below the flag leaf.
Evergreen Tree Diseases
Somehow April flew by without me reminding you to apply fungicide sprays to Austrian and Ponderosa pines that have had 
problems with Sphaeropsis tip blight in the past. I’ve also received several scotch pine samples in the office to diagnose for pine wilt nematode. While there is no cure for pine wilt, I recommend to take a 6” long, 1-2” diameter sample of a dead branch to your local Extension office for diagnosis before cutting down the tree. Pine wilt affects Austrian (long needles groups of 2) and Scotch pines (short needles in groups of 2) as they are non-native trees while the nematode is native. Since ponderosa pines (long needles in groups of 2 and 3) are native to Nebraska, they don’t seem to be affected by pine wilt nematode.
Pine wilt is caused by beetles carrying pine wood nematodes vomiting them into the water-carrying vessels of the tree (xylem). The tree senses the nematodes and essentially blocks water to those branches. Often you will observe a branch then perhaps a side of the tree and eventually complete death of the tree within 6-9 months. While I have diagnosed many samples of pine wilt, more often when I visit homeowners the tree problems are due to fungal diseases which occur on the needles. If you look closely at your needles and observe dark bands or rings on them followed by death of the needle either direction from the band, the tree problem is most likely due to a fungal needle blight like dothistroma in Austrian and Ponderosa pines or brown spot in Scotch pines. They can all be prevented by spraying a fungicide containing copper sulfate in the spring.
With everything about 3 weeks early this year, now is the time to spray Ponderosa and Austrian pines for needle blight and spruce trees that have had problems with needle cast or shoot blight where the new growth has died in the past. In early June spray for needle blight problems in Scotch pine and cercospora blight on cedars. If you have a windbreak of combinations of these trees and don’t want to spray twice, I recommend at least spraying in early June to catch all of them. Increasing air flow by cutting out some trees is another way to reduce fungal diseases on your trees.
Also watch trees for bagworms as you may be able to tank mix a fungicide/insecticide application in early June if needed. We would recommend picking the bags off trees and burning them, but that’s just not feasible in windbreak situations. To know when to spray, take a few of the bags off the tree, place them into a plastic ziplock bag, and place outside on the south side of your house. When the larvae emerge from the bags, check your trees to see if larvae can also be observed on them. Pyrethroid insecticides are recommended for managing bagworms because they cause an irritation that makes the larvae leave the bags and allow them to be exposed to the pesticide.
Great brochure! Evergreen Diseases
Drop #Soybean Seeding Rate & Save $
Increasing input costs are forcing producers to evaluate every decision they make. With soybean seed costs on the rise, producers in the Greater Quad County On-Farm Research group wondered if they could reduce their soybean populations while maintaining yield and saving money. On-farm research conducted in field scale, randomized, and replicated farmer plots and at the South Central Agricultural Laboratory near Clay Center from 2006-2008 proved producers could.
Since 2006, planting rates of 90,000, 120,000, 150,000, and 180,000 seeds per acre have been planted in 12 irrigated soybean fields on 30-inch rows. Prior to this research, most of these producers usually planted 160,000-180,000 seeds/acre. The 90,000 low rate was determined based on UNL research recommending not to replant a hailed soybean stand if at least 90,000 plants/acre remained in the field.
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In 2008, cooperating producers used these same rates to plant soybeans at five sites with 20 replications. Planting dates ranged from April 29 to June 3. In the end, there was little difference in percentage stand and yield among the four planting rates (see Table 1). The 120,000, 150,000, and 180,000 yields were statistically the same (only a 0.3-bushel difference between the 120,000 and 150,000 rates) and were significantly better than the 90,000 seed-per-acre plots; however, note that the 90,000 plot yielded only 1.7 bu/ac less than 150,000 plot. All data was statistically analyzed to determine the yield differences due to the various treatments.
The findings are similar to the 2006 and 2007 studies. In 2006, yield results ranged from 65.5 bu/ac at 90,000 to 67.4 bu/ac at 180,000. In 2007 yield results were 59.4, 59.6, 59.4, and 60.2 bu/ac for 90,000, 120,000, 150,000, and 150,000 respectively with no statistical difference.
Most likely, these results are indicative of soybean’s ability to compensate for reduced populations. Figure 1 shows increased plant branching at lower populations compared to less branching at higher populations. This was observed in all fields regardless of variety. Also observed in 2008, were two additional nodes/plant at the 90,000 population compared to the 180,000 population. Nodes are important as flowers, pods, and ultimately yield are produced from them.
A dryland field in Nuckolls County also showed interesting results. This field was hailed at the cotyledon stage, so planted populations of 100K, 130K, and 160K became average actual stands of 74,417; 89,417; and 97,917 plants per acre. August rains in 2006 helped deliver yields of 38.6, 40.6 and 42.7 bu/ac, respectively.
Figure 1a. Lower planted populations of 120,000 compensated for reduced plants by increased branching, flowering, and pod set, regardless of typical variety architecture.
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Figure 1b. Fields with planted populations of 150,000 were observed having a more erect architecture with reduced branching compared to fields planted at rates of 120,000. |
Rates for Drilled Soybean:
In 2006, one drilled field in irrigated conditions in Fillmore County yielded 68.4 bu/ac, 66.6 bu/ac, and 67.2 bu/ac for planting rates of 150,000, 175,000, and 190,000 seeds per acre respectively. Another study in 2006 conducted by the Soybean Feed Grains and Profitability Project in a rain-fed field in Lancaster County showed a slight but significant yield advantage to drilling soybean at a rate of 152,500 seeds per acre compared to 115,000 seeds per acre. Yield for the higher seeding rate was 56.8 bu/ac compared to 56.0 bu/ac with the lower seeding rate. When using grain drills and reducing soybean populations, variable seed spacing and seed depth within a drilled row can be an issue for soybean emergence. This is why a population increase for drilled beans is often recommended.
Recommendation: Plant Soybeans at 120,000 Seeds/Acre
Based on three years of consistent research results, UNL specialists recommend reducing planting populations from an average of 160,000 seeds/acre to 120,000 seeds/acre in 30-inch rows. This reduction of 40,000 seeds per acre results in a savings of $10.66 to $18.57 per acre based on seed costs of $40-65 a bag. For three years producers were able to achieve a 90% stand and have not seen a statistical yield variance from 150,000 or even 180,000 seeds/acre. With soybean seed costs increasing, reducing soybean planting populations is another way producers can survive high input costs of crop production.
Plant #Soybeans Early for Increased Yields
While I got this posted in our CropWatch Web site, I didn’t get it on my blog till now! Hopefully this inspires many of you to get soybeans planted yet this week! 
Planters are rolling throughout the state and given the size of today’s equipment corn planting is rapidly progressing. Based on UNL research, we would encourage you to consider planting your soybeans as soon as possible—preferably before the end of April for the southern two-thirds of Nebraska and or the first week of May for the northern third of Nebraska. While evening temperatures have been low, consider the percent risk of frost for emerged plants not planted seeds. The above recommendation considers a 10% risk of frost 7-10 days after planting, the time when soybeans would most likely emerge.
Why plant early? Five years of UNL small plot and on-farm research has proven that early planted soybeans yield more than late planted beans—regardless of whether the spring has been cold and wet or warm and dry. Soybeans are a photoperiod-sensitive crop so the goal is to allow the plant to use the sun’s energy to accumulate as many nodes as possible as day length decreases after June 21. Nodes are important because that’s where pods, seeds, and ultimately yield are produced. The goal is to have the soybean canopy “green to the eye by the fourth of July!”. Thus the plants are absorbing all the sunlight possible not allowing any to be wasted by hitting the soil.
Table 1 shows how three years of on-farm research have resulted in an average of 3 bu/ac yield increase (with a range of 1-10 bu/ac depending on the year and the planting date range of early versus later planting). With today’s soybean prices, a 3 bu/ac yield increase adds up (see Table 2). We do recommend a fungicide/insecticide seed treatment to reduce the risk of damping off diseases and bean leaf beetles which tend to feed on early-planted soybeans.
Several previous CropWatch articles explain soybean planting date in more detail. Please see these for more information:
- For Increased Yields Plant Soybeans in Next Two Weeks
- Three Reasons Why Soybean Planting Date Matters
- Farm Research Shows Benefits of Planting Soybeans Early
- Risks and Caveats of Early Planting Soybeans
Table 1: Nebraska On-farm Research Early and Late Planted Soybean Yield Results (2008-2010)
|
Year |
Producer |
Date |
Reps |
Rainfed/ Irrigated |
Variety |
Row Spacing |
Yield (bu/acre) |
|
2008 |
SCAL Early |
Apr. 29 |
3 |
Irrigated |
Producers 286 |
30” |
67.2 |
|
2008 |
SCAL Late |
May 15 |
3 |
Irrigated |
Producers 286 |
30” |
65.8 |
|
2008 |
Seward Co. Early |
Apr. 30 |
3 |
Irrigated |
NC+ 2895 |
30” |
68.4 |
|
2008 |
Seward Co. Late |
May 19 |
3 |
Irrigated |
NC+ 2895 |
30” |
66.2 |
|
2008 |
York Co. Early |
Apr. 23 |
8 |
Irrigated |
Producers 286 |
30” |
66.9 |
|
2008 |
York co. Late |
May 14 |
8 |
Irrigated |
Producers 286 |
30” |
63.5 |
|
2008 |
Fillmore Co. Early |
Apr. 30 |
7 |
Irrigated |
Pioneer 93M11 |
30” |
81.0 |
|
2008 |
Fillmore Co. Late |
May 19 |
7 |
Irrigated |
Pioneer 93M11 |
30” |
77.5 |
|
2009 |
SCAL Early |
Apr. 27 |
4 |
Rainfed |
Pioneer 93M11 |
30” |
37.6+ |
|
2009 |
SCAL Late |
May 18 |
4 |
Rainfed |
Pioneer 93M11 |
30” |
37.2 |
|
2009 |
Saunders Co. Early |
May 3 |
6 |
Rainfed |
NC+ A63RR |
15” |
66.6 |
|
2009 |
Saunders Co. Late |
May 21 |
6 |
Rainfed |
NC+ A63RR |
15” |
65.1 |
|
2009 |
SCAL Early |
Apr. 27 |
4 |
Irrigated |
Pioneer 93M11 |
30” |
70.2 |
|
2009 |
SCAL Late |
May 18 |
4 |
Irrigated |
Pioneer 93M11 |
30” |
68.1 |
|
2009 |
Fillmore Co. Early |
Apr. 24 |
4 |
Irrigated |
Pioneer 93M11 |
30” |
69.5 |
|
2009 |
Fillmore Co. Late |
May 15 |
4 |
Irrigated |
Pioneer 93M11 |
30” |
68.4 |
|
2009 |
Seward Co. Early |
Apr. 24 |
4 |
Irrigated |
NC+ 2A63 |
30” |
73.2 |
|
2009 |
Seward Co. Late |
May 20 |
4 |
Irrigated |
NC+ 2A63 |
30” |
71.3 |
|
2009 |
York Co. Early |
Apr. 30 |
3 |
Irrigated |
NK 28B4 |
30” |
59.1 |
|
2009 |
York Co. Late |
May 15 |
3 |
Irrigated |
NK 28B4 |
30” |
58.6 |
|
2010 |
Saunders Co. Early |
Apr. 18 |
6 |
Rainfed |
Channel 2751 |
15” |
75.7 |
|
2010 |
Saunders Co. Late |
May 18 |
6 |
Rainfed |
Channel 2751 |
15” |
71.2 |
|
2010 |
Seward Co. Early |
Apr. 19 |
6 |
Irrigated |
Channel 3051RR |
30” |
72.0 |
|
2010 |
Seward Co. Late |
May 24 |
6 |
Irrigated |
Channel 3051RR |
30” |
62.3 |
|
|
Average Early |
|
|
|
|
|
70.0* |
|
|
Average Late |
|
|
|
|
|
67.1 |
*Statistically significant at 95% level.
+SCAL Rainfed was not included in the combined statistical analysis but Saunders Co. Rainfed was compared with irrigated yields from other locations.
Table 3: Economic Advantage to a 3 bu/ac Yield Increase Due to Early Soybean Planting Date
| Price of Soybeans | $ 7.00 | $ 8.00 | $ 9.00 | $ 10.00 | $ 11.00 | $ 12.00 | $ 13.00 | $ 14.00 |
| Economic Advantage | $ 21.00 | $ 24.00 | $ 27.00 | $ 30.00 | $ 33.00 | $ 36.00 | $ 39.00 | $ 42.00 |
JenResources 