Extension Update from Jenny Rees

UPCOMING EVENTS:  
Aug. 14:  Project Sense Field Day, Lower Loup NRD, near Monroe, NE, 5 p.m.-7 p.m.
Aug. 16:  Project Sense Field Day, Central Platte NRD, Ken Seim farm near Chapman, NE, 10 a.m.-Noon
Aug. 16:  Corn Disease Diagnostic Workshop, 5:30-7 p.m., Activity Building, Clay Co Fairgrounds, jrees2@unl.edu
Aug. 17:  Corn Disease Diagnostic Workshop, 10-11:30 a.m., 4-H Building, York Co. Fairgrounds, jrees2@unl.edu
Aug. 18:  Rain Garden Installation Design Workshop for landscape professionals, Earl May in Columbus, Contact Kelly Feehan kfeehan2@unl.edu
Aug. 22:  Project Sense Field Day, Upper Big Blue NRD, Cole Anderson farm near Beaver Crossing, NE, 11 a.m.-1 p.m.
Aug. 23:  Crop Management Diagnostic Clinic:  Soybean Production Training, ARDC (now ENREC) near Mead, 8:30-5pm RSVP http://ardc.unl.edu/cmdc.shtml
Aug. 24:  Crop Management Diagnostic Clinic:  Corn Production Training, ARDC (now ENREC) near Mead, 8-4pm RSVP http://ardc.unl.edu/cmdc.shtml
Aug. 24:  West Central Crops and Water Field Day, West Central R&E Center, North Platte,http://cropwatch.unl.edu/2017/west-cental-water-and-crops-field-day-aug-24
Aug. 24:  York County Corn Grower Plot Tailgate, 5-7pm, 1416 Road I, York County.
Aug. 25-Sept. 4:  Nebraska State Fair, http://www.statefair.org
Sept. 6:  Sorghum Field Day, Mike Baker Farm near Trenton, NE, 5:00 p.m., RSVP (402) 471-4276
Sept. 7:  Sorghum Field Day, John Donicek Farm near Lawrence, NE, 5:30 p.m., RSVP (402) 471-4276
Sept. 8:  Sorghum Field Day, John Dvoracek Farm near Farwell, NE, 11:00 a.m., RSVP (402) 471-4276
Sept. 12-14:  40^th Husker Harvest Days near Grand Island, http://huskerharvestdays.com/hh17/Public/Enter.aspx

Farm Finance Clinic Sites and Dates To sign up for a clinic or to get more information, call Michelle at the Nebraska Farm Hotline at 1-800-464-0258.

Crop Updates:  Most corn fields are soft dough to beginning dent and soybeans are in seed fill.  Corn at beginning dent still needs an estimated 5” of water to finish and soybeans in seed fill need between 6.5” (beginning) to 3.5” (end) of seed enlargement to finish.  Questions this past week centered around the cooler conditions and how that may potentially impact yield.  Hopefully with current corn growth stages, this will only help with the filling process.  I haven’t personally taken time to run Hybrid Maize simulations the past few weeks but hope to this week.  We do have an article in this week’s CropWatch which shares potential yields based on this year’s weather conditions and compared to historic 30 year weather-data under “perfect conditions” based on the planting dates we provided.  For Clay Center area, assuming corn was planted by April 24, the Hybrid Maize model is currently simulating irrigated corn to be mostly average with a slight potential of being above average yields.  It’s simulating mostly below average yields for non-irrigated corn.  You can view the full article at:  http://go.unl.edu/43vc.

I’ve also received a number of questions regarding soybeans turning red.  In most cases, the petioles are red/green and leaves may have red veins on the undersides of leaves.  Sometimes these beans are lodged allowing leaf undersides to be exposed.  From most discussions, the consultants and farmers don’t feel the soybeans are stressed, which may allow for sugar accumulation.  Nothing I’ve seen appears to be cercospora leaf blight which can cause the upper side of soybean leaves to become red in color and leathery.  This disease can also cause a purple seed stain of soybean and tends to be more variety dependent.  I don’t feel this is the problem from what I’ve currently seen.  Ultimately I think this is just more environmental/physiological from the cooler nights we’ve had and where we’re at in soybean development.  There’s the potential for anthocyanin (red pigment) accumulation, sugar accumulation, and even potential sun burn of some of the leaves.  Discussions with Loren Giesler, Jim Specht, and Roger Elmore all tend to be in agreement.  Purdue University shared the following article back in 2006:  http://www.coolbean.info/pdf/soybean_research/mid_late_season/Purple_Stem_SPS.pdf.  We also found the following Q/A CropWatch article from Jim Specht back in September 2008 that I will share below.  Perhaps some of these additional characteristics are common in the fields you are seeing red soybean petioles and leaves in.

“This year you may have noticed an unusual soybean leaf color — bronze or dark gold rather than the more typical bright yellow — as soybeans begin to mature. This is not due to a fungus and does not indicate a problem.  This bronze coloration is quite evident in certain varieties…that contain the gene for producing significant amounts of anthocyanin pigmentation when the fall days are sunny bright, but not hot, and the nights are cloudless and cool. This pigmentation does not become evident until the leaf’s green coloration, which masks the color, begins to fade as the plant’s chlorophyll degrades and the plant matures and dries.  Varieties producing this kind of pigmentation have:  purple (not white) flowers, tawny (not grey) colored pubescence (i.e, “hairs” on the plant stems, leaves, and pods, although the term “hair” is not a scientifically correct term), brown (not tan) colored pods, and black (not other) colored hilum on the seed coat (i.e., the hilum is the point where the seed is attached to the pod).  Plants must undergo a gradual maturation for the coloration to be visible before leaf shed. With these varieties, you will see a slight but deep purple coloration in the pods near the top of the canopy, petioles connecting the upper leaflets to the stems, and the leaflets themselves.  As the plants dry down and start losing their green pigmentation, the pigmented leaves will take on a bronze color (deep purple when observed up close) before the leaflets and petioles are shed from the plant and the pods dry down.  Consider this coloration to be a beautiful but very transient expression of color in your soybean field, much like the fall color in trees but not as long-lasting.”

Bagworms:  Infestations of bagworms are still high on some evergreen trees and surprisingly some of the larvae feeding are fairly small for this time of year.  We’re still recommending to treat if you find bagworm larvae on your trees and use a product containing bifenthrin in it.  This active ingredient causes an irritation to the larvae so they come out of the bags and are exposed to the chemical if they are still in the feeding stage. 

Trees:  Many have noticed tree leaves turning yellow or brown the past few weeks and are concerned about trees.  You also may be noticing stress coloration (early fall color) developing in some trees.  Apple and crabapple trees in particular may have yellow/brown leaves and thin leaf canopies due to fungal diseases such as apple scab and cedar-apple rust.  We don’t recommend spraying anything for them right now.  Oak, ash, hackberry, maples, sycamore amongst others may be showing yellowing leaves with leaf drop or browning of leaves in clusters as well.  This is most likely due to environmental stress from the high heat we had several weeks ago.  This may be coupled with drought stress depending on the location and situation.  We would recommend providing adequate irrigation now and correctly mulch trees to help reduce stress.  Some parts of the State have abnormally dry conditions.  A reminder that trees and shrubs need late summer and fall watering to prep them for winter survival. This is a critical time for watering trees and shrubs to prevent winter injury.  Moisten the soil around trees and shrubs, and just beyond the dripline, to a depth of 8 to 12”. Avoid overwatering; but continue to water well into fall as long as dry conditions persist.

Another interesting situation has been noted by foresters as “sudden limb drop”.  This is when what appeared to be a strongly attached branch falls from a tree for no apparent reason.  Hot, dry conditions tend to encourage this occurrence and there’s not good understanding as to why it happens.  It could be due to the roots’ inability to keep up with moisture needs of the tree, translocation issues of water throughout the tree, the wood becoming dry and thus weaker causing the limb to fall, or the tree amputates the limb because it can’t properly circulate enough water for the whole tree.  During periods of extreme heat, consider not parking under trees and moving potential targets (picnic tables, etc.) from directly under tree canopies (at least until weather cools or moisture resumes).