Our Insights | Crop Protection
August 24, 2016

Corn Ear Tip Back - Not Always Nitrogen/Nutrition Related

Many factors can affect ear development.  This specific case points to two different hybrids with distinctly different genetic backgrounds.

 

Nutrition requirements were met, as shown by the NDVI, however environmental issues can still affect yield.

 

The hybrid that produced the ear on the right did not handle the environment in 2016 as well as the hybrid that produced the ear on the left. The heat we experienced over the past 4 weeks took (what would have been) the higher yielding hybrid and significantly reduced the top end yield.  This particular hybrid's leaves do not roll up to conserve moisture, but laid normal and exposed more leaf surface area thus did not slow down respiration.  This caused the plant to overheat and lose yield.

 

The hybrid represented by the ear on the left started to wrap it’s leaves up as the stomata closed during the higher temperature days. This conserved moisture as well as plant health and yield.

  • Corn plants pollinate as many kernels as the plant senses it can fill by taking an inventory of plant nutrition, moisture, and photosynthesis. Kernel abortion occurs when the plant undergoes stress 2 to 4 weeks after pollination. Stress from lack of moisture, excessive heat, cloudy weather, and nutrition imbalance are the usual suspects to limit protein development necessary to fill those kernels.

 

  • Limiting plant stress is primarily the responsibility of 4 elements: nitrogen, sulfur, potassium and boron. Nitrogen is the primary nutrient used to manufacture protein and each of the other 3 elements improve the efficiency of the nitrogen. Sulfur, boron and potassium are critical for plant function to cope with heat, and drought by regulating stomata and cell structure.

 

  • Kernel abortion can also be tied to a specific hybrid in the way it stores each nutrient and protects itself from the heat and drought.

 

  • This year nitrogen has not been the limiting factor so we tend to look at the other factors such as hybrid, moisture stress timing, sulfur, boron, and potassium for determining kernel abortion.