August 21, 2020

posted by Andrew Blomme on 8/21/2020 in Weekly Newsletter

Week of August 21, 2020

The 2020 crop year has been one of the most interesting years yet and walking through fields every day allows me to observe the crop as it progresses through this growing season. I will be sharing what I see in fields across our territory in these weekly newsletters. These newsletters can include crop conditions, crop physiology, weather conditions, pest pressure, disease pressure, and other interesting interactions that I run across over the course of a week.

The corn crop varies quite a bit from Cass Co. up through Audubon to Carroll Co. This picture to the right is one of the bright spots of the week. It was taken on Monday in eastern Cass Co. This field caught some timely rains after tassel that have really taken it far. It just started to dent (R5). At the start of R5 it typically takes 30 days to get to black layer, but drought conditions may shorten that period.

The picture to the left was taken in eastern Audubon county. This is typical symptomology of drought stress we have been seeing lately. When the plant is unable to get water and nutrients through root uptake it results to pulling the water and nutrients from its lower leaves to fill in its kernels. In this picture these plants have cannibalized up to its 10th leaf. The ear leaf in this case is the 14th leaf. It is pretty incredible that corn breeders have “tricked” hybrids to focus on maintaining yield at the expense of itself.

The past two weeks have involved walking through a lot of twisted corn. The severity of lodging has been affected by location, topography, and hybrid characteristics.

Root Lodged Corn

Leaning corn is not too hard to spot right now. Root lodged corn is continuing to photosynthesize and contribute towards yield. There is not a lot of good university data to say how much root lodging this late in the season effects yield. Michael and I should have a good amount of data to look at this winter to try to quantify any yield effect.

Kinked Stalk Below the Ear

Many spots experienced strong enough winds to put a “kink” in the stalk below the ear. Surprisingly, 10 days later those plants are still green and photosynthesizing. If you are worried about damaged stalks leading to dead plants, they would be brown and drying out by now. Nutrient and water movement in those kinked plants is severely restricted though, much like a kink in a garden hose. Maturity will be slowed drastically and drydown of those kernels will be uneven.

Hybrid Differences

Different hybrids were affected differently by this wind. Hybrids can have different root structures and root strength scores which effect its susceptibility to lodging. Lodged corn tends to lead to more of a hassle at harvest and has affected how a lot of people are approaching harvest this year.

Soybean Conditions

As of late, soybean fields have held up reasonably well in these dry conditions. In general, the spots with poorer soils in a field are starting to show in the form of water stressed beans. Disease and insect pressure are very low throughout the area. The majority of beans in the area are in the stage R6 (Full Seed). Here in the next 7-10 days you will notice leaves start to turn yellow as the shorter maturity beans begin to reach maturity.

The pod set of a single soybean plant. 1 one-bean pod,

27 two-bean pods, 60 three-bean pods, and 4 four-bean pods