Agronomy Zone 4

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In parts of Missouri we are finding some very confused corn in the fields lately.  I have seen corn that is either not emerging correctly or, in some cases, not emerging at all.  We have found cases of corn that is literally growing upside down, as the growing point is headed deeper into the soil and the roots are rising to the surface; in addition, seedling blights are attacking the seedlings. 

The reason for this unusual growth pattern is due to a cold, heavy rain followed by prolonged cold weather after planting.  In this case, the rains cooled the soil above the seed to a colder temperature then the soil below.  As a result the growing point, which tends to grow toward warmer temps, actually turned and went deeper, and alternately the roots started growing up toward the surface.  As temparatures rebounded and soil temps normalized, then the plant tried to change the direction of growth. The picture above shows some example of corn seedlings with these malformed mesocotyls.  In these situations, the mesocotyl will develop an S curve or sharp bend in it.  If you look closely you can see the roots that started growing up and not down at the 45 degree angle that it should have.  This is a very rare thing to happen, and (fortunately) most people will not ever see this.

Meanwhile, as all of this was happening, the cool wet soils allowed the seedling blights to attack the seed and plants.  This has led to some replant situations.  We are also seeing seeds sitting in cold soils and getting attacked before they could even germinate. 

One more thing: we also are seeing western bean leaf beetle adults already feeding on the volunteer soybeans, so an insecticide with your burn down spray could pay big returns for you this year.

The University of Illinois conducted research where corn was planted at a depth of 2 inches on a silt loam soil on top of NH3 injection bands. In this study, there were three NH3 injection depths (4, 7, and 10 inches), three dates of planting (0, 1, and 2 weeks after NH3 application), and two nitrogen (N) application rates (100 and 200 lb N/a). There was also a control treatment where no NH3 was applied.

The 100 lb N/a rate showed no reduction in stand compared to the control 27 days after planting for any injection depth or date of planting. The 200 lb N/a rate showed significant stand reduction at a 4-inch NH3 injection depth, but no stand reduction at the deeper depths when planted the day of NH3 injection.

Depth of injection more important than days

Plant height was slightly stunted 41 days after planting when 100 lb N/a was injected the same day as planting at a 4- or 7-inch depth; if injected at 10 inches there was no stunting apparent. While, the 200 lb N/a showed severe, slight, and no stunting for the 4, 7, and 10 inch NH3 injection depths, respectively.

Overall, depth of NH3 injection was more important in reducing injury than was the amount of time between NH3 application and planting.

Follow these guidelines to minimize corn injury

To prevent or minimize injury when planting corn a few hours after NH3 application, Lang advises farmers to: 

• Inject NH3 at least 7 inches deep and perhaps as deep as 10 inches if possible. 
• Do not plant the corn row directly on top of the injection bands. If possible, apply NH3 at an angle relative to the corn rows. 
• Lower N application rates will minimize risk of injury (e.g. typical N rates in corn-soybeans vs. corn-corn situations).
• Ensure that the soil closes behind the knife openings to limit N loss and movement upwards towards the seed.

Corn planting is finally done in Texas.  Due to the rains, corn planting was 3-4 weeks late and some acres did not get put in.  The corn that did get planted is up and doing very well. 

Oklahoma had good weather for planting, and so the corn went in and is doing well at this time. 

Southeast Kansas and Southwest Missouri are, for the most part, done planting corn.  The corn is in good shape, despite a late frost that does not appear to have hurt any of the crop. 

Central and western Kansas have experienced very nice weather for a timely planting season.  But now, with most of the corn in the V2 to V4 stage, high winds and heat are causing the crop to show signs of early stress. 

Very little corn is planted north of I-70 in Central Kansas. 

Eastern Kansas and western Missouri are in good shape overall.  In some places, farmers have very little corn in due to the ground drying out after it was worked, but about 70 percent of the acres are planted. 

Central And eastern Missouri have about 80 percent of the corn planted, and it appears to be emerging in good shape.

Some soybeans have been planted in all the above-mentioned areas, but it is too early in the planting season to determine how they are doing and how much of the soybean crop is in the ground.

Last year was a season that showed us many of the common problems with growing crops, and gave us new insights to many pests and diseases.  Some of the problems were wet grain, wet fields, drought, molds in the crops, ear problems (shape, kernel set issues, pinched ears, etc.) and, in th case of soybeans, Sudden Death Syndrome.  Most of these issues could be found in any field last year, and some fields had many of these problems. 

Attached to this blog posting is some informational brochures to help you learn about some of these issues.  These pieces are designed to help you understand what causes the issue, what to look for, what control options exist, or what will happen to the crops.  Also one shows some new work that has be done to help understand how Sudden Death Syndrome has been able to spread from small pockets to whole fields and how we can try to control this issue.  With information comes better farming, as you can help take some of the yield robbing issues off your acres or lessen their impact to your crops.  So take sometime and download the brochures and kept watching this site for future information that could help you.

Common Corn And Soybean Issues