Blog Archives

JenREES 6-24-18

Crop Update: What a blessing to have rain this past week! Grateful for how it provided much needed moisture into the top two feet in many cases. Updated soil moisture status will be at http://jenreesources.com. Some in our area and in other parts of the State received wind, hail damage, and flooding to crops. This week’s CropWatch at http://cropwatch.unl.edu shares information for those situations. A few summarizing points: for those with greensnap or with severe hail damage, you may wonder what potential yield may be based on your planting date and current plant stand. The following chart from Iowa State University and explanation of how to understand it may be helpful: https://crops.extension.iastate.edu/cropnews/2009/05/assessing-corn-stands-replanting.

Corn Plant Date-Stand Count-Yield Chart

Source: Iowa State University

For those with flooding, corn in the V7-10 leaf stage can survive for about 7-10 days in flooded water. Temperatures above 86F can result in greater stress on those plants than if the temps remain cooler than that during that time. Another consideration for the future, it’s not uncommon to find a disease called ‘crazy top’ of corn when the tassels begin to emerge. We’ve seen this the past several years where creeks or areas along waterways or field edges were ponded. There’s nothing you can do to prevent this.

For those with hail damage, damage from V7-10 leaf corn can result in a number of situations depending on the severity of hail. Minimal yield loss is assumed for leaf damage in crop insurance charts. Final plant stands will be important which will account for broken off plants that don’t recover. Stem bruising also isn’t factored in. For corn, bacterial diseases tend to be my larger concern at these growth stages. Bacterial top rot is one in which the plant dies from the top down and has a strong odor to it and creates a soft, slimy mess. Goss’ wilt is another concern-particularly systemic Goss’ wilt. You can check for this if you have a dying plant that doesn’t have a soft rot by taking a

Systemic Goss Wilt Clay Co-Rees

Cross-section of stem showing systemic Goss’ wilt in the discolored vascular bundles.

cross section of the stem and looking for discoloration of the vascular bundles. You can also send plants like this to the Plant and Pest Diagnostic Lab in Lincoln for confirmation.

Regarding fungicide use on hail damaged corn, Iowa State and the University of Illinois did studies finding similar results. Both found no statistical difference in applying a fungicide vs. the untreated check in spite of small numerical differences. Regarding timing, the Iowa State study simulated hail damage at tassel and applied fungicide an average of 3 days and 8 days post-hail. There were no statistical differences on yield of the timing of the applications either. They did find statistically less fungal diseases in the hail-damaged plots vs. the non-hail damaged plots and speculated it was due to more air flow and less leaf area available for disease to occur. I have observed that fungicide can help with stalk strength and maintaining whatever green tissue remains when we had the 2013 hail storm in Clay County at brown-silk to blister corn. But this early, it’s hard to justify a fungicide application based on the data that’s available. If you’re interested in testing this for yourself, the following is an on-farm research Fungicide Protocol for Hailed Corn and Soybean.

For hail damage on soybean, many of the beans are at flowering or approaching flowering. Again, stem bruising isn’t counted in crop insurance assessments. I haven’t really observed bacterial or other disease issues necessarily from stem bruising in soybean. What tends to be more of an issue is those plants hardening off and becoming brittle to walk through. For soybeans, the blessing is that often new buds form and you will see increased branching which can help with canopy closure…it just can hurt right now when soybeans were already near canopy and we’re trying to reduce additional inputs for weed control. Things to consider are that pods may be closer to the ground from this increased branching and you may need to harvest earlier to help with getting beans that become brittle before snapping off in wind storms. I leave plant stands of near 60,000 plants/acre based on our soybean pop studies that received hail damage. If you want to prove any replanting differences to yourself, you may wish to consider the following Soybean Replant Protocol. We’d recommend waiting on herbicide apps till some new growth occurs, which is difficult when I’ve watched palmer essentially be not affected by hail and put on two new leaves within a few days in the past. Last year we started making herbicide apps 5-7 days post-hail. Additional hail resources are at a new resource called ‘Hail Know’ at: https://cropwatch.unl.edu/hailknow. There’s a lot of info I haven’t transferred to this site yet…but you can view photos and comments on hail recovery at numerous growth stages over time at my blog under the ‘Storm Damage’ category:  https://jenreesources.com/category/storm-damage-2/.

Last week I shared the following video regarding determining timing of off-target dicamba movement to soybean: https://youtu.be/rQid7-vX-TU. Sharing again with an increase in the number of fields that were experiencing cupped symptoms last week.

Crop Updates-May 2016

IMAG1694

May 27:  Sunshine has been welcomed for corn amidst the rains we’ve received. Corn ranges from 1-4 leaf depending on emergence dates. For those who put the majority of nitrogen application pre-plant, soil and/or foliar samples may be necessary to determine the extent of nitrogen available to the crop throughout the season.

IMAG1693

May 27:  Receiving numerous calls on marestail escapes in corn this year.  At this point, there’s no options guaranteed for 100% control.  Our Guide for Weed Management shows options for 80% control right now including:  Buctril + atrazine, Buctril + dicamba, Hornet, Realm Q, Resolve SG/Solida or Resolve Q, and Status.  Please read and follow all label instructions.  For soybeans, options are even more limited and control mostly goes down to 70%.  Page 116 of our Guide for Weed Management provides options for consideration.

IMAG1713

May 27:  Also was called to a field for unique situation to me.  Field had been two years of soybeans before planted to corn this year and had received hail 2 days before and over 4″ of rain within a few day period.  Night crawler trails and holes the diameter of pencils existed throughout the field.  The hail-stripped leaves were being moved down into holes.  Where the stripped leaves were still attached to plants, the entire plant was bent over into the holes.  It’s a unique situation in which the corn will hopefully outgrow with warm weather and sun.   This unique occurrence is also mentioned at the following Purdue University website:  http://extension.entm.purdue.edu/pestcrop/2010/issue9/index.html 

May 23:  Corn is looking good for the most part with few major concerns yet.  Some have commented on the yellow-looking corn.  This is most likely due to cool, wet soils rather than any nutrient issues.  There may be field-specific issues such as saturated soils, compaction, and some herbicides that can cause this yellowing too.  Also had a call on cutworms in seed corn but not widespread calls on this yet.  Extension Educators have set up light traps for tracking cutworm moths and you can find that information here:  http://go.unl.edu/rhhe.  Cutworms will cause the most damage the first 7 days after corn emergence so scouting is important.  The York County Corn Grower Plot was planted on April 24th with the corn currently at 2 leaf stage.  Special thanks to Ron, Ray, and Brad Makovicka for hosting and the work put into this plot each year!

2016-05-20 16.16.39

May 23: Soybeans are emerging and the concern several have discussed is crusting.  Soybeans have an amazing ability to push through crusted soil and we were hoping for rains this past weekend to soften the soil and help them along.  I’ve watched soybeans lose both cotyledons when trying to push up through the soil. Surprisingly these can survive if the growing point is still intact, and a small plumule will begin to develop.

IMAG1701

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. 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.  Information from Purdue University shows that losing both cotyledons can lead to 2-5% yield loss.

2016-05-11 09.44.31

May 15: After last week’s storms, some have wondered how long their germinated seed and emerged plants could survive under water.  There isn’t a great deal of research regarding germinated corn hybrid seed.  From some corn inbred research, it is not expected that germinated seed can survive in flooded conditions for more than four days.  Within 48 hours, soil oxygen becomes depleted and crusted soils from heavy rains can lead to reduced emergence.  A two day flooding event after soybean seed germination and imbibition (water uptake) reduced soybean stands from 20-43% in research conducted in the early 2000s. Corn less than 6 leaf growth stage at temperatures less than 77F can survive around four days.  Temperatures higher than 77F may only allow those emerged plants to survive around 24 hours. As waters recede and for those who received hail on young corn, it will be important to monitor your plant stand.  The high rains received early May 2015 in Nuckolls and Thayer counties resulted in a number of early corn diseases including bacterial soft rot and systemic goss’ wilt which reduced plant stands.  We also saw an onset of anthracnose and a Xanthomonas bacterial disease that we couldn’t do anything about.  Correct diagnosis will also be important. We would recommend monitoring your plant stand in ten areas of your field, counting plants from two adjacent rows in each area and assessing the distance of gaps between plants.  Digging in the areas where gaps occur can help determine if seedlings still have an opportunity to survive.  Seedlings that have leafed out underground or are corkscrewed will most likely not develop normally and may never make it out of the ground; it’s a judgement call on your part.  An article is also provided in CropWatch this week to help with stand assessment for corn replant decisions at:  http://go.unl.edu/iic6.  One thing to keep in mind with the final decision table from Iowa State is that it all rests on an assumption of optimum planting of 35,000 seeds/acre planted in a window between April 20-May 5.  That may or may not be a realistic assumption for your field conditions.  Another thing to keep in mind is that while on average, as planting dates move into May, corn yields tend to drop, 2016 may not be an average year and the best planting date for 2016 with the weather conditions we’ve had may not have been the earliest ones.  Regarding gaps, ISU shares gaps from 1.3-2.8 feet result in an additional 2% yield reduction while 4-6 foot caps result in an additional 5% yield reduction.

May 1:  It never ceases to amaze me how quickly planting occurs each year!  Corn planted the week of April 10th has emerged and for those fields that received hail from last week’s storms, I’m hoping we don’t see disease issues later on.  Also of note, some have asked me about the CropWatch soil temperatures as they are higher than what some of you have been measuring in your fields before planting.  The CropWatch soil temps at http://cropwatch.unl.edu/cropwatchsoiltemperature are averages of 24 hours under bare soil which may be different than the residue conditions in your fields and is an average of the entire day vs. one point in time.  This may help explain some of the differences.

Many stands of alfalfa are lush green with over a foot of growth at this point.  I looked at some alfalfa in Clay County that got dinged by cold temperatures in areas of the field and stopped growing.  At this time I’m also finding quite a few aphids and a few alfalfa weevils.  A disease common this time of year called spring black stem can be observed in nearly all alfalfa fields right now in the lower canopies.  This disease consists of small black lesions on the leaves which eventually cause the leaves to turn yellow and drop.  Normally this disappears with later cuttings as humidity and rainfall are typically high during the first cutting and can be managed with cutting the alfalfa.  One option to consider according to Dr. Bruce Anderson, our Extension Forage Specialist, is to consider cutting alfalfa before bloom.  He shares that weather can cause long delays and alfalfa doesn’t bloom very aggressively during spring.  Bruce felt there were advantages to cutting alfalfa when it is 15-20” tall before bloom during first cutting including:  weather compared to later spring, spread out alfalfa harvest if you consider cutting one field earlier, reduction in insect and disease problems by early harvest, and high feed value.  It also potentially allows the second cutting to be ready before the summer heat which can lower forage quality.  Disadvantages include lower yield from cutting early which could be made up in later harvest, regrowth may be slower if cut early, and the need to allow for longer recovery after first or second cutting to maintain long-term stands.  So, harvesting before bloom may be something you wish to test in one of your fields this year and consider how this works for you, especially if you did have some frost damage or are having insect/disease issues in your alfalfa right now.

Crop Update Pure Nebraska 5-20-16

Pure Nebraska

Crop Update June 9

Corn that was hail-damaged on June 3rd is starting to regrow.  Leaves wrapped up in the whorl are beginning to slough off as wind and warm temperatures cause the damaged tissue to die and break off.  For more information on how stand loss impacts yield, please check http://cropwatch.unl.edu.

Corn that was hail-damaged on June 3rd is starting to regrow. Leaves wrapped up in the whorl are beginning to slough off as wind and warm temperatures cause the damaged tissue to die and break off. For more information on how stand loss impacts yield, please check http://cropwatch.unl.edu.

Some corn plants more severely affected were reduced to sticks.  Sometimes no new growth is appearing while in other plants new growth can be seen.  I split open the stem on this plant.

Some corn plants more severely affected were reduced to stems. Sometimes no new growth is appearing while in other plants new growth can be seen. I split open the stem on this plant since no new growth was apparent and the center looked discolored.

In this corn plant, a bacterial rot has set in as can be seen from the discoloration at the upper portion of this plant and the discoloration at crown area.  This plant may not survive.  This is typical of what we were seeing in Nuckolls/Thayer counties with the 8-10

In this corn plant, a bacterial rot has set in as can be seen from the discoloration at the upper portion of this plant and the discoloration at crown area. This plant may not survive. This is typical of what we were seeing in Nuckolls/Thayer counties with the 8-10″ of rain they received there.  My concerns for corn at this point are bacterial diseases such as this or Goss’ wilt that may continue to reduce stands through the season.  Some growers are considering a fungicide application but fungicides don’t target bacterial diseases.  We’d recommend anyone considering this to consider an on-farm research experiment and I’d be happy to help set this up for you.

These soybeans were reduced to stems yet are showing new growth 5 days later.  UNL research has shown that soybean stands can be greatly reduced without a significant yield effect.   The other thing we have looked for is bruising on stems.

These soybeans were reduced to stems yet are showing new growth 5 days later. UNL research has shown that soybean stands can be greatly reduced without a significant yield effect. Several growers are considering replanting; we’d recommend taking into account the research or conduct an on-farm research experiment to see any differences for yourself like this farmer did.  The other thing we have looked for is bruising on stems and some flooded areas truly did not have plants survive.  For more information, please check out http://cropwatch.unl.edu.  

#Ag Tour Day 1

UNL Extension Ag Educators from throughout Nebraska gathered together in late October for an excellent professional development tour toWhat is that bush and how many educators does it take to figure it out?  Apparently a lot and we still sent it to Elizabeth Killinger! Iowa and Minnesota!

Before the bus started moving we were working on plant identification for a client.  Then we learned about the status of Emerald Ash Borer among other pests at the Douglas-Sarpy County Extension Office.  By the end of the presentation we were considering getting a meat thermometer and recordable Hallmark card!  (will explain later).

Along the way, John Wilson provided an update regarding the flood recovery efforts from the 2011 flood.  He mentioned at Gavins Point Dam, the lake would have drained every 25 hrs. when releases were occurring for  the flood.  He was involved with an effort in putting togetherJohn Wilson speaking a webinar that involved 25-30 agencies and 14 speakers from 5 states.  During the recovery there were 2″ to 25′ drifts of sand in fields.  One piece of ground that was reclaimed cost $125-150K and needed 7 excavators for a month.  One 300 acre piece of ground that wasn’t reclaimed was going to cost $10,000/ac. to reclaim it.

John Hay provided an update regarding wind energy.  He pointed out the different types of towers along the way as we passed several wind farms.  Facts included:  a 1.5Megawatt wind turbine can run 1000 homes each and the gear box is turning 2000:1 compared to the blades.  Iowa is #1 in  percent of electricity produced from wind power (20%) and it costs $3-6 million each to install a wind turbine (essentially double the cost of how many megawatts).  The life span of a turbine is 20 years with a maintenance cost about $0.05/kwh.  When considering efficiency, wind turbines are 40-50% efficient vs. coal power (35%), nuclear (35%), cars (25%); so they’re more efficient at converting free energy into electricity but they are less cost John Hay speaking about wind energy.efficient than those other energy sources.  Windfarms also typically pay for themselves in 5-10 years.

Our first stop was at Hawkeye Breeders where we saw their semen storage facility that essentially had enough semen to fertilize every cow in the U.S.  They ship all over the world and their primary customer is the dairy industry.  We also toured their semen collection facility and got the coolest pen from there.

From there we stopped at Blue River Organic Seeds and were surprised to learn that all their organic seed research is done conventionally.  They provide organic seed for corn, alfalfa, soybean, and various forages and are looking for more growers.  We also learned about PuraMaize which was developed by Dr. Tom Hoegemeyer to essentially block pollen from outside sources to maintain purity.Semen storage at Hawkeye Breeders.

That night we had supper with faculty from Iowa State University talking about programming efforts there, including their manure programming, ag economics, and Roger Elmore spoke of the corn programming there.  But before that, a few of us took advantage of the 45 min. of time to get a few geocaches in the area 🙂

IMAG2514 Geocache #1Geocache #2

Storm Damage to Crops

Memorial Day storms hit us again this year, this time with the EF2 tornado in Edgar.  I checked NE Rain, and for the month, Clay County One of an estimated over 100 pivots damaged in Clay County during the Memorial Day storm. received between 5.9-9.7″ of rain with nearly 3/4 of that coming in the last 6 days !

Even with the saturated soils and localized flooding, there is still potential for drought.  It was this way last year at the end of May before the rains shut off in early June.

I’ve received questions regarding potential storm damage to crops.  Normally I’ve found that waiting a week helps with determining regrowth and decisions.  Overall, we’re fortunate that crops were so small.  Much of the corn was V1-V3 and the soybeans were anywhere from not planted to cotyledon stage.  The majority of damage occurred where emerged plants were silted over with soil and/or residue, standing in water for periods of time, of left with stems due to high wind and/or hail.Creeks overflowed banks and localized flooding can be seen throughout the County with standing water in fields.

Corn Decisions

According to Purdue University Agronomist, Bob Nielsen, it takes around 48 hours for oxygen to be completely depleted from saturated soils.  Plants that are emerged above the water have a better chance of survival than those below it; however, it’s hard to tell exactly how long plants can survive in those conditions.  We also have several areas where plants were standing in water for a few days, the water receded, and now they’re standing in water again.   Only time will tell how those plants will fare.Corn plants, once at V3, damaged during storm.

Because the growing point of affected corn plants is below ground, in many situations, plants should recover if the growing point remained healthy.  Hopefully only small areas will need to be replanted.  For crop insurance decisions and options, please check out the following CropWatch article.

Soybean Decisions

Some emerged soybeans that were at cotyledon stage have been reduced to stems leaving gaps between healthy plants.  Soybean plants can compensate for reduced populations; however length of gaps and final stands do need to be assessed for replant decisions.  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 seeding rates of 100,000, 130,000, and 160,000 seeds/acre were planted. This Damage to newly emerged soybean.  These plants were at cotyledon stage.  Arrows show plants reduced to stems.  Will need to assess gap lengths and plant stands to make replant decisions.field was at the cotyledon stage when it was hailed. Some plant stands dropped to 67,000 plants/ac. Yield was 4 bu/ac less than in the 160,000 seed/acre planting that had a final stand of nearly 98,000 plants/ac. 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.  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, in the event that the gaps between plants are not large and are fairly even.

Many of the soybeans worst affected were reduced to stems.  Last year we watched as soybeans continued to develop plumules after the hail events and soil crusting in our area.  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, 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 as in this picture.  Plumule emerging from damaged soybean seedling that had been reduced to a stem.

In summary,

we will monitor damage early next week to help with replant decisions.  Overall, I feel we are fortunate that the crops were so small and crop damage does not appear to be severe other than all the pivots that need to be replaced.  We will also need to watch for potential disease damage in weakened plants.  For crop insurance decisions and options, please check out the following CropWatch article.

Residue Concerns

The recent rains have left their impact on fields throughout the county and Nebraska in general.  I’ve received several questions this week regarding flooded fields and how to help crops buried beneath piles of residue.  

For flooded fields, Bob Nielsen with Purdue University wrote an excellent article to address these concerns.  In short, our cooler temperatures will help plants survive better, but plants completely submerged under water in saturated soils for more than 48 hours don’t stand much of a chance for survival.  You can read his entire article here.

If there’s one thing I would like to see farmers reconsider, it’s stalk chopping.  It seems like every year we deal with heavy rains washing stalks from fields where they pile in certain areas of the fields burying plants, covering roadside ditches or jamming creeks.  Talking to my colleagues and to several area farmers, we’ve all considered burning as an option.  However, burning may only get the top-most dry material while the material underneath is still wet and won’t burn.  Another farmer correctly pointed out that there’s usually so much silt intermingled with the residue that it’s hard to get a good burn anyway.

Keith Glewen, UNL Extension Educator in Saunders Co. suggests you consider harrowing  or possibly rotary hoeing the stalks, knowing that the depth of stalks and the period of time which elapses following a heavy rain event are important factors in determining success or failure in managing the unwanted stalks.  There’s a short amount of time to get that residue off those plants if there’s no light getting down to them.  In some situations in the county, residue is up to 1 ft. deep over the top of plants.  Harrowing can help even out the field and emerged seedlings may be damaged, but the growing point for corn is still below ground at this point.  For emerged beans, the growing point would be above ground so harrowing wouldn’t be a good option.  With the rains again today and forecast for more in the future, I’m not even sure that harrowing is much of an option right now for corn as it will take awhile to get back into the fields.  In places where 1 ft. of residue is burying plants and the inability to get to those piles with the wet conditions, I don’t expect much plant survival there. 

For now we’ll have to wait and see.  In the mean time, evaluate your operation and the need for chopping stalks.  If you don’t detach the stalk it won’t move.  UNL on-farm research found no yield benefit to shredding vs. not shredding stalks in the research which can be found here.

%d bloggers like this: