Corn Progression After August 2013 Storm

On August 1, 2013, a severe wind and hail storm damaged 170,000 acres of corn and 86,000 acres of soybeans in Clay County, Nebraska. Corn at the time of the storm was from brown silk-blister. While the storms in the Gibbon/Blue Hill areas occurred a little earlier in the growing season, the following photos show the progression of damage in the event it can be of help to those affected by 2014 storms.

Field on August 2nd that was totaled out and planted to cover crops.

Field on August 2nd that was totaled out and planted to cover crops.  Where crop insurance allowed, producers considered various forage options.

Some producers chose to spray fungicides on fields with more foliar leaf tissue such as this one.

Some producers chose to spray fungicides on fields with more foliar leaf tissue such as this one.

Hail damage to stalks shown 4 days after the storm.

Hail damage to stalks shown 4 days after the storm.

Splitting the stalks open 4 days after the storm resulted in seeing stalk rot already beginning to set in.

Splitting the stalks open 4 days after the storm resulted in seeing stalk rot already beginning to set in.

Corn on August 2nd in blister stage in which hail stones made kernels all mushy on one side of the ears.

Corn on August 2nd in blister stage in which hail stones made kernels all mushy on one side of the ears.

Corn ear on August 6th.  Notice moldy kernels appearing on side where hail damaged ear.

Corn ear on August 6th. Notice moldy kernels appearing on side where hail damaged ear.

 

Six days after the storm, the good side of the ear that didn't receive hail damage.

Six days after the storm, the good side of the ear that didn’t receive hail damage.

Six days after the storm, the side of the ear that received hail damage.

Six days after the storm, the side of the ear that received hail damage.

33 days after the storm, kernels on the "good" side of ears were beginning to sprout.

33 days after the storm, kernels on the “good” side of ears were beginning to sprout.

33 days after the storm:  Diplodia set in creating light-weight ears and brittle kernels.  Sprouting occurring on damaged kernels on sides of ears.

33 days after the storm: Diplodia set in creating light-weight ears and brittle kernels. Sprouting occurring on damaged kernels on sides of ears.  The presence of mold does not automatically mean a mycotoxin is present. Producers also wondered about the safety of feeding moldy grain to livestock.

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.

Is that a Webworm or a Bagworm?

Originally posted on Husker Hort:

Webworms, bagworms, are they the same thing? If not, why does it make a difference whether you have a bagworm or webworms? It can make a big difference which insect you have to control and the damage that they cause. Correct identification is key to know how to control these pests.

Fall webworms or tent caterpillars are an occasional pest. They are sometimes called ‘bagworms,’ but using the correct common name will help clear up confusion. They appear as white webbed nests on the ends of branches in cottonwood, crabapple, walnut, and other trees. The caterpillars hide in the webbed nest during the day and feed on the trees at night. The caterpillars cause little harm to otherwise healthy trees. Tree health is not usually affected until more than 50 percent of the foliage is eaten. If there are enough nests, about one on every branch, the tree could be…

View original 573 more words

Hail Damage Meetings

Hail Damage Meetings in York and Hamilton Counties.  Please click on image to enlarge.

Hail Damage Meetings in York and Hamilton Counties. Please click on image to enlarge.

Storm Damage Resources

Flooded field

Field flooding occurred in newly planted and newly emerged fields throughout the area after recent rains.

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Large trees were uprooted falling on buildings, homes, and cars in Sutton after the May 11, 2014 tornadoes.

The Mother’s Day 2014 storms caused significant damage in Clay County and other areas of the State.  It never ceases to amaze me how people throughout the area respond to storm damage!  Clay County has had its share, and yet the attitude of those affected has been one of thankfulness-thankfulness that no one was injured and that so many still have their homes in spite of damage.  It’s also wonderful to see people from all over the County and area pull together with each storm-helping each other out bringing themselves and equipment to pick up debris or help however possible.  It’s a blessing to work with and serve the people of this County!

Resources

As clean-up continues, the following are a list of resources that may be helpful to those affected by the storms.  Thoughts and prayers go out to all who were affected!

 

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