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Ag Reflections from 2014

Happy New Year!  Wishing all of you and your families a wonderful 2015!  As I look back at 2014, there are several ag-related observations that I noted throughout the year.

tornado damage in Sutton

Cleanup after the tornado in Sutton on Mother’s Day 2014.

The first observation continues to be the way communities and people in this County/area pull together in difficult times.  Whether after tornadoes/wind storms or helping other farm families who had an injured family member or had lost a family member, it’s just a blessing to see the way people pull together to help each other in time of need.  It was also a blessing for many who were unable to harvest in 2013 due to the August 1st storm, to harvest fields in 2014, and for many in the area to experience really good irrigated and dryland yields this year.

The dry winter of 2013/14 allowed for very mellow ground during planting time.  Often seeding depth ended up ½-1” deeper than intended.  The dry winter also didn’t allow for good residue decomposition leading to problems during planting and ensuing stand emergence.  Cutting off residue and high rains in May led to unintended consequences of replant situations when residue was moved off of farmers’ fields onto neighboring fields, suffocating emerged plants in portions of fields.  I’m not sure what the solution is for the future other than it really needs to be something worked out with neighboring farmers, but perhaps mentioning it here opens an opportunity for future conversations.

Cover crops have been incorporated into more operations in recent years, yet the ultimate goal for using them remains important in determining what species/crops are used in the fields.  We also realized the importance of determining amount grazed prior to turning cattle into fields (whether for grazing cover crops or crop residue), as high winds in winter 2013/14 in overgrazed fields led to soil blowing throughout the winter.

Systemic Goss Wilt Clay Co-Rees

Systemic Goss’ wilt showed up in some fields that were hail and/or frost damaged by V6.

The May frost showed us emerged soybeans at the cotyledon stage held up well to the frost compared to the corn.  We also again watched Goss’ wilt show up systemically by 6 leaf corn that was injured early by frost or hail in fields where Goss’ wilt had been a problem in the past.  We need more research/understanding of this disease.  Wheat continues to show us its resiliency as it winterkilled in portions of fields, withstood drought-stress, and then made up yield in the last 4-6 weeks.

Perfect pollination conditions coupled with high solar radiation, low night-time temperatures, and timely rain events were keys to the bountiful corn crop we experienced this year.  Soybeans were more of a mixed bag. In walking fields and in conversations with farmers, I think the disappointment in some irrigated yields could be attributed to early/over-irrigation, disease problems, and planting date.  UNL on-farm research showed on average a 3 bu/ac yield increase when soybeans were planted in late April to first week of May (regardless if growing season was warm/dry or cold/wet like it was this year) and those I’ve talked to who achieved 80+ bu/ac in the area this year planted in that time-frame.  I’m curious if there’s something to planting a 2.4-2.5 maturity early vs. a 3.0+ maturity early as some area producers are seeing strong yields from a shorter season hybrid planted early the past few years.  So if you’ve also seen this and/or are interested, that will be an on-farm research project to try next year.  Please let me know if you’re interested!

Here’s wishing you a healthy and prosperous 2015!

Crop Update 8/1/14

Southern rust of corn confirmed in Clay County July 31.  This was found on one leaf in a field near Trumbull.  Just because southern rust has been found in the area, we don't recommend automatically spraying.  Scout your fields and consider disease pressure, growth stage, and economics.  Long season corn and late-planted fields have the potential for most damage.

Southern rust of corn confirmed in Clay County July 31. Very small, tan-brown lesions on upper surface of the leaf, usually in clusters.  Spores inside the pustules are typically orange.  This was found on one leaf in a field near Trumbull. Just because southern rust has been found in the area, we don’t recommend automatically spraying. Scout your fields and consider disease pressure, growth stage, and economics. Long season corn and late-planted fields have the potential for most damage.  Secondary common rust sporulation has also been confused as southern rust as the secondary pustules tend to look like this.  It’s important to obtain microscopic confirmation to know for sure if you have southern rust in your fields.

Spores of southern rust appear elongated vs. common rust appear as near perfect circles.

Microscopic Observation:  Spores of southern rust appear elongated vs. common rust appear as near perfect circles.

Another common problem is old common rust lesions being confused as gray leaf spot.  The color of this lesion is a tan-gray, typical of gray leaf spot.  Using backlighting or a handlens, you can see the pustules within this lesion confirming it is common rust and not gray leaf spot.  I've had many calls that gray leaf spot was up the entire plant in their fields and after looking at fields, have found it to be common rust in most situations.  It's important to know what disease you truly have to make the best decision on fungicide application.

Another common problem is old common rust lesions being confused as gray leaf spot. The color of this lesion is a tan-gray, typical of gray leaf spot. Using backlighting or a handlens, you can see the pustules within this lesion confirming it is common rust and not gray leaf spot. I’ve had many calls that gray leaf spot was up the entire plant in their fields and after looking at fields, have found it to be common rust in most situations. It’s important to know what disease you truly have to make the best decision on fungicide application.

Have also received questions on soybeans, particularly in dryland.  Soybeans are drought stressed-often showing it in pockets within dryland fields right now.  Closer observation shows plants aborting pods and losing lowest leaves.  Spidermites can also be viewed on leaves in some of these patches.

Have also received questions on soybeans, particularly in dryland. This photo is showing drought stressed soybeans-often occurring in pockets within dryland fields right now. Closer observation shows plants aborting pods and losing lowest leaves. Spidermites can also be viewed on leaves in some of these patches.

Dryland corn showing stress as well.  June rains were making for dryland crops with potential, but also led to shallow rooting.  Crops could use a drink right now....but would prefer no more ice and hail.  The storm that hit Clay County so hard occurred one year ago today.

Dryland corn showing stress as well. June rains were making for dryland crops with potential, but also led to shallow rooting. Crops could use a drink right now….but would prefer no more hail and tornadoes. The storm that hit Clay County so hard occurred one year ago today.

Corn Disease Look-Alikes

Physoderma brown spot

Physoderma brown spot on corn. While the small, speckled lesions may look like southern rust, under hand lens or microscopic observation, there are no raised pustules as would be the case with southern rust. Also notice the brown/purple discoloration on the midrib which is also noticed on the stalk as well where the leaf color meets the stalk.

Fair week tends to be time for tasseling in corn and considerations for watering and fungicide application are being made.  Regarding diseases in corn, there has been confusion about a few diseases, particularly about a disease called physoderma brown spot which some have confused for southern rust.  The fungus causing physoderma brown spot feeds on pollen and debris on leaves and does not cause harm to the corn plants themselves.  Because the spores of this fungus move via water (it’s closely related to oomycetes), numerous lesions can appear on leaves in bands or areas where water collects.  While the lesions may look like early southern rust, there will be no pustules present and often purple colored lesions will also be observed in the midrib, leaf sheath, stalk, and outer husks.

Differentiating Rusts:

2013-07-30 09.31.26

Southern rust in corn. We currently have not seen southern rust in Nebraska in 2014. Notice how you can see raised pustules in this picture compared to the photo of physoderma brown spot above.

When differentiating between southern rust vs. common rust, there are several criteria to consider and this NebGuide is a great resource.  Typically common rust will have brick-red pustules randomly scattered on the upper and lower leaf surfaces that are larger in size.  It is common rust that we are currently seeing in our fields.

Bacterial leaf blight showing up heavily in some hybrids.  The UNL Plant and Pest Diagnostic Lab is determining species and we will share more information in the future.  There is no control for this disease at this point.

Bacterial leaf blight showing up heavily in some hybrids. The lesions are red-brown in color, long and skinny and mostly vein-limited.  Older lesions spread outside the veins and are buff in color-sometimes they are being confused as gray leaf spot.  The UNL Plant and Pest Diagnostic Lab is determining species and we will share more information in the future. There is no control for this disease at this time of the season.

Southern rust in our area tends to have very small, raised, tan-orange pustules on the upper leaf surface of leaves in localized areas on mid-upper leaves.  These pustules are tightly clustered on the leaves. However, color and size are relative as sometimes the two diseases can look alike.  Microscopic observation is the best way to differentiate the two diseases.  Fungal spores from Puccinia sorghi causing common rust will be near perfect round circles whereas fungal spores fromPuccinia polysora will be oblong in shape.

We do have some gray leaf spot in the lower canopies and I haven’t seen much northern corn leaf blight in the fields.  But we do

have a bacterial leaf blight that is affecting quite a bit of leaf tissue on some hybrids.  These lesions are long and skinny appearing at first to be limited to the veins.  There’s been concern about these lesions being severe gray leaf spot but it’s not and there’s nothing you can do about the bacterial disease.  Please don’t mistake this bacterial disease as a fungal one and trigger a fungicide application too early.

Fungicide Application Timing

We tend to see southern rust in our part of the State each year; it’s a matter of time.  Triggering a fungicide application too early may result in no residual for when you need it if/when southern rust occurs.  Every year some producers make more than one fungicide application due to blanket applications at tassel or shortly after followed by another fungicide application when southern rust occurs later in the year.  Consider good fungal resistance management and apply fungicides when disease pressure warrants them in your fields and also consider economics for your situation for proper fungicide application timing.

Nebraska On-Farm Research Network Testimonials

Listen to the value of on-farm research to these participants!  Sound interesting to you?  Learn more by checking our our On-Farm Research website or contacting any of our faculty involved!

Sprouting Corn Kernels on Hail-Damaged Ears

The latest event in the Clay County storm occurring August 1st has become germination of “good” kernels left on the ears that have been damaged by"Good" side of hail-damaged ear is now sprouting before black layer. hail.  This event of kernel germination prior to harvest is also called “vivipary”.

Typically we wouldn’t see this occur before black layer because of the hormonal balance within the kernels-particularly the balance between gibberellin and abscisic acid.  According to a study by White, et. al (2000), Gibberellin production with the lack of ABA allowed for kernel germination while less Gibberellin and more ABA deterred kernel germination.  At full maturity, very little ABA is left in the kernel (in both corn and soybeans) which allows them to germinate in correct conditions after harvest.  But this can also allow for sprouting in the ear after black layer when corn is still drying down, particularly in tight-husked, upright ears with conditions of high humidity or rain after black layer.  Sprouting under those conditions typically occurs at the base of the ear first.

Why are kernels sprouting before we’ve reached black layer?

That’s a good question.  I haven’t found much in the way of scientific explanation other than the thought that the hormonal balance of the kernels can be altered by physical damage from hail, bird feeding, and grain mold.  Some ear mold fungi also produce gibberellic acid which can lead to a hormonal balance shift in these ears stimulating germination.  I also haven’t observed that this is hybrid-dependent and am finding as much as 25-50% sprouted ears in various areas of hail-damaged fields.

What can you do now?Ear damage by hail and sprouting occurring before black layer.

Make sure your crop insurance adjuster is aware of the situation and make sure to submit samples for kernel damage due to mold, sprouting, and check for mycotoxins prior to harvest.

The local co-op may or may not choose to accept the load depending on percent damage and the standards they need to follow.  If the load is rejected, contact your crop insurance agent to determine your next step.  DO NOT bin the grain on your farm until you contact your insurance agent as they have specific rules that need to be followed in the case of grain rejected due to mycotoxins or kernel damage from storms.

Sprouted kernels lead to higher kernel damage and more fines in a load.  Keys for harvest will include harvesting early, getting corn dried down to 14%, potentially drying at a high temperature to kill the sprout, screening out fines, and monitoring stored grain closely for hot spots, mold, and additional sprouting grain.

You can also choose not to take it to grain right now, and honestly, that may be the best option for several of the hail-damaged fields.  Silage is still an option and it would be recommended to sample the green chop going into the silage pit for potential mycotoxins.  Mycotoxin level does not change with fermentation so cattle feeders would have a good idea of any mycotoxin levels if sampling was done in this manner.  See this post for additional information on making silage.

Additional information:Diplodia and other ear mold fungi on hail-damaged ears.  Now sprouting is occurring before black layer.

Du-Pont Pioneer.  (2007).  Field Facts:  Pre-mature Germination of Corn Kernels.

Nielsen, R.L. (2012).  Premature Corn Kernel Sprouting (aka Vivipary).  Corny News Network, Purdue University.

White et. al.  (2000).  Gibberellins and Seed Development in Maize. II. Gibberellin Synthesis Inhibition Enhances Abscisic Acid Signaling in Cultured Embryos.  Plant Physiology Vol. 122 no. 4 pg. 1089-1098.

Wiebold, B. (2009). Wet Weather Can Cause Seeds to Sprout before Harvest. Integrated Pest & Crop Management Newsletter, Univ of Missouri.

Goss’ Wilt in Corn

Goss’ wilt was found this week in corn damaged from Memorial Day storms in Clay County.  I’ve also received pictures that appeared toGoss' Wilt in Corn in Nebraska with characteristic black "freckles". be Goss’ from crop consultants in other areas of the State.  Goss’ wilt lesions have a wavy edge, have a varnished look to them when wet, and have characteristic black “freckles” within and particularly along the lesion edges.  We are seeing some plant death due to the systemic version of Goss’ wilt.  This can be seen by taking a cross-section of the stem and looking for orange discoloration in the vascular bundles.  Because this is a bacterial disease, fungicides are not effective in controlling Goss’ wilt.  If you are interested in trying a product that is labeled for treating bacterial diseases in corn, we would recommend you test its effectiveness via on-farm research.  Spraying in a paired comparison treatment design will give you a true answer if the product made a difference for you or not.

To do this simply:Paired Comparison Design with buffer rows for on-farm research comparison

1-Spray a pass or round with the product (depending on sprayer size) to ensure you can harvest two passes from the center of the treated area.
2-Skip the same amount of distance as you previously sprayed.
Repeat steps 1-2 at least three more times

Mark a few plants in each plot and take photos throughout the growing season to determine if disease progresses or not.  You may also wish to keep track of percent of plants affected in each untreated and treated area throughout the season, and check for percent stalk rot and harvest population in each area before harvest as well.

Make sure to harvest two passes from the center of each treated and untreated Split plot harvest design for on-farm research comparisonarea.  Then compare the weights as shown in the harvest figure.  Please let Jenny Rees jrees2@unl.edu (402) 762-3644 know if you decide to conduct this study and if you have any questions!  

More information:

Goss’s Wilt from UNL
Sample Submission to UNL Plant and Pest Diagnostic Clinic
Nebraska On-Farm Research Network

Crop Update 6-20-13

The sun has been welcomed and crops are rapidly growing in South Central Nebraska!  Corn right now is between V6-V8 (6-8 leaf) for the most part.  Quite a few farmers were side-dressing and Corn that's been hilled in south-central Nebraska.hilling corn the past two weeks.  It never fails that corn looks a little stressed after this as moisture is released from the soil and roots aren’t quite down to deeper moisture.

Installing watermark sensors for irrigation scheduling, we’re finding good moisture to 3 feet in all fields in the area.  The driest fields are those which were converted from pasture last year and we want to be watching the third foot especially in those fields.  Pivots are running in some fields because corn looks stressed, but there’s plenty of moisture in the soil based on the watermark sensor readings I’m receiving for the entire area.  So we would recommend to allow your crops to continue to root down to uptake deeper moisture and nitrogen.

The last few weeks we observed many patterns from fertilizer applications in fields but as corn and root systems are developing, they are growing out of it.  We’ve also observed some rapid growth syndrome in plants.  This can result from the quick transition we had from cooler temperatures to warmer temperatures, which leads to rapid leaf growth faster than they can emerge from the whorl.  Plants may have some twisted whorls and/or lighter discoloration of theseOn-farm Research Cooperators, Dennis and Rod Valentine, get ready to spray their corn plots with a sugar/water solution.  Their study is to determine the effect of applying sugar to corn on yield and economics.  leaves, but they will green up upon unfurling and receiving sunlight.  This shouldn’t affect yield.

Damping off has been a problem in areas where we had water ponded or saturated conditions for periods of time.  We’ve also observed some uneven emergence in various fields from potentially a combination of factors including some cold shock to germinating seedlings.

We began applying sugar to our on-farm research sugar vs. check studies in corn.  We will continue to monitor disease and insect pressure in these plots and determine percent stalk rot and yield at the end of the season.

Leaf and stripe rust can be observed in wheat fields in the area and wheat is beginning to turn.  We had some problems with wheat streak mosaic virus in the area again affecting producers’ neighboring fields when volunteer wheat wasn’t killed last fall.  Alfalfa is beginning to regrow after first cutting and we’re encouraging producers to look for alfalfa weevils.  All our crops could really use a nice slow rain right now!

Wheat Scab Potential Risk

With the recent rains in Nebraska, the potential for wheat scab has increased.  This video shares more information including a fungicide table of products to consider with product efficacy ratings for scab.  For more information, please check out http://cropwatch.unl.edu.  Thanks to Rachel Stevens, UNL Extension Intern, for producing this video!

Sugar Applications to Crops

For the past ten years I’ve come across farmers who really believed in applications of sugar to reduce their pest populations.  Being no research to my knowledge to prove it, I tucked the observation in the back of my head for future reference.  With farmers looking to increase yields and looking to other farmers such as Kip Cullers for information, some of our on-farm research producers were curious about sugar applications in their operations with the hopes of increasing yield.

Nebraska On-Farm Research Corn Results

Using the application rates that Kip Cullers uses, one Clay County producer applied 3 lbs of sugar (purchased pallet of cane or beet sugar from the local grocery store) per 10 gallons of water at V7-V8 on corn in 2010-2011.  Cullers also tanked mixed the sugar solution with a post-herbicide application like glyphosate but this producer didn’t do that.  To simulate any affect of the water or driving through the field, he also drove through the untreated check spraying water only.  Two  years of research results showed no significant increase in yield.  However, there was a noticeable difference in standability at harvest.  This producer did not apply a foliar fungicide either year.  When it came to harvest, this producer needed the reel in 2010 for the untreated check.  Stalk rot ratings were taken using the pinch test two weeks prior to harvest.  To him, the $1.25/acre of sugar was worth it to improve standability even if yield was not significantly improved.  You can view the full research report here.

2010-2011-SugarOnCorn On-Farm Research Clay County Nebraska

Several York County producers have also tried this with one producer finding a non-statistical 2 bu/ac yield difference with the check yielding better while the other producers found a statisically significant 2 bu/ac increase to the sugar treatment.  Another producer in Hamilton County is testing this using the corn product he grows-using 1 qt of corn sugar (high fructose corn syrup) per 10 gal of water applied still at V7-v8.

In 2012, a small plot study was conducted at UNL’s South Central Ag Lab near Clay Center to determine any differences between sugar application, fungicide application, and untreated check in corn.  All treatments were applied at R2.  Because of the drought in 2012, there was minimal disease pressure, thus there were no significant differences between the three treatments regarding area under the disease progress curve.  The untreated check did show the most stalk rot (via the push lodging test).  The sugar application reduced the lodging rating by half and the fungicide application showed the lowest lodging rating.  For yield, there were no significant yield differences with the untreated check yielding the highest followed by the fungicide and sugar applications.  The entire study report can be found here.

In Soybeans we have had producers apply 3 lbs sugar in 10 gallons of water at R3 (beginning pod).  In all years, there have been no significant differences in yield.  Lodging ratings were not taken as that is more variety and water dependent.

Additional research…

has shown that application of sugar to crops increases the numbers of beneficial insects in those fields.  South Dakota research entomologists showed that lady beetles benefited from a combination of prey and non-prey foods.   In a follow-up study, these entomologists applied sugar sprays to soybeans and quantified the frequency of sugar feeding by analyzing the gut contents of common lady beetles in three states.  They found all the tested lady beetles regularly consumed sugar-like nectar in soybean fields, even when it wasn’t applied as a supplement.  They also found more lady beetles in the sugar treated plots compared to the untreated plots.

At this time we can’t explain the standability effect we’re seeing from our sugar applications to corn.  Our hypothesis is that early application of sugar to corn is increasing beneficial microbes that may be keeping the exposed brace roots and stalks healthier.  We hope to conduct more research in the future to answer this question.

In conclusion,

the application of sugar to corn and soybeans has not always shown increased yield.  However, in nearly all of the corn studies, sugar treated plots have shown increased stalk strength at harvest.  Research has also shown an increase in the number of beneficial insects in fields where sugar was applied.  Further research is needed to understand the interactions aiding stalk strength in corn.

If you are interested in conducting on-farm research studies in your field, please contact any of our UNL Extension Educators or Specialists!  You can also follow the conversations this year via our Facebook page and Twitter feed!

What do you think of sugar applications to crops?  Have you tried this in the past and if so, what were your results?

Youth Discover Crop Science

An excellent opportunity for youth to become detectives and have fun while learning about crops and science! Consider having a youth you know attend this Big Red Camp and learn more about agriculture careers!  There are also scholarships available to attend!

Views from VanDeWalle

Are you interested in science, agriculture, plants, crops, insects, or diseases? If so, join our team of detectives to solve crop-related problems in the Crop Science Investigation (CSI) Big Red Camp! Become a detective while participating in hands-on sessions to learn about and increase your knowledge of crops, science, and agricultural careers. Youth detectives will interact with agronomic professionals across Nebraska to solve experiments in: nutrient management; managing disease, insect and weed problems; water management; crop production, and much more! Do you have what it takes to become a CSI detective?

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There are a variety of careers related to plant sciences such as:Agricultural Communicator; Agronomist; Crop Consultant; Crop Insurance Adjuster; Educator; Co-op Manager; Farmer or Rancher; Farm Credit Banker; Field or Lab Researcher; Plant Breeder; Soil or Water Conservationist; Seed, Fertilizer, or Chemical Sales; or Technical Representative.

Scholarships are available in the amount of $300 to participants who…

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