Agronomy Blog

Eastern Iowa Crop Progress

by Ryan Dunsbergen | Jul 10, 2017

The corn crop in Eastern Iowa, as a whole, is looking really good.   We were very dry during the first half of June.  Several corn fields had plants at the V6 – V8 growth stage that were rolling leaves.  I also saw a lot of corn that had a bluish look to it in the V4 – V5 growth stage.  These corn plants were suffering from Rootless Corn Syndrome and had very little root growth.  The hot, dry weather combined with fields being slightly too wet at planting caused the furrow row to open.  The corn plants were not able to root down with no soil and no moisture around the root crown.  Thankfully, in the last half of June we had cooler temperatures and much needed rain that resolved those problems.  These fields have been able to root down and find their Nitrogen source and green up.  

Several fields of corn have tasseled in Southern Iowa with a lot more set to begin to tassel this week.  As you move north, the amount of corn that has reached the reproductive stages gets less and less.  The most advanced corn fields in Northern Iowa are still a leaf or two away from tasseling.  Due to the weather conditions in the spring that led to a wide range of planting dates, we will see a wide range of tassel dates as well.  While most areas of Eastern Iowa have had ample moisture there have been some pockets that missed several rains.  With the higher than normal temperatures forecast for the next two weeks, along with the high moisture demand of corn during tassel, most corn fields could use more rain to get through this critical stage development of the crop.       

One major “black eye” of the Eastern Iowa corn crop has been multiple hail events.  There have been pockets of hail damage all throughout the region.  Most corn was in the V5 to V7 stage of growth development when the hail came.  The good news is the growing point is either below the soil surface or slightly above the soil surface at these stages.  Most producers kept their crop and did not replant.  The bad news is the loss of stand.  There were several fields where the wind damage was greater than the hail damage.  Instead of the plants being broken completely off, they were bent over and twisted up.  Although the growing point was not damaged, several of these corn plants were not able to grow out of their twisted whorls.  Some farmers are looking at final stands that were reduced in half down to roughly 15,000 plants per acre. 

Soybeans are off to an average start in Eastern Iowa.  Soybean fields that were planted before the middle of May look really good.  However, soybeans planted towards the end of May and early June really struggled with emergence.  In some cases the V-slot cracked open and turned into concrete with the hot, windy weather we experienced.  In these fields the soybeans were able to get the hypocotyl out of the ground but not the cotyledons.  Consequently, the hypocotyl snapped and the cotyledons were left underground.  In other cases the beans simply did not have enough moisture in the top two inches of soil to germinate and grow.  We have had plenty of moisture now to soften the soil and germinate soybeans, but a lot of the damage has already been done.  Most soybean fields are in the R1 to R3 reproductive stages and they finally took off and got some height to them last week.    

The same hail events that hit the corn fields also hit the bean fields.  All soybeans were in the vegetative stage when the hail hit.  Defoliating soybeans in the vegetative stages has very little impact on yield.  However, in fields where the hail reduced soybean stand or broke nodes off soybean plants, yield loss is to be expected.  Breaking 50% of the nodes off a soybean plant in the early vegetative stages will reduce yield by 10 – 15 percent.  Furthermore, hail injury to stems early in the season can result in stems becoming brittle and lodging later in the season.    

Overall in Eastern Iowa we have had a good, but not great, start to the crop growing season.  As we all know, we have a lot of growing season left.  There are still many things that can happen that will affect this crop for the better or for the worse.  If you have any crop questions or concerns please get in touch with someone on the LG Team.  We would love to help.  Thank you so much for your continued business.  We greatly appreciate it!


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