This was one of the most difficult planting seasons I can remember. I don’t know how farmers coped with it. Mother Nature was cold and wet during the spring. I hope it was not a preview of things to come with climate change. We have talked about completing corn planting by May 10. Many farmers hadn’t even started by May 15 this year.
From emergence to V10 leaf stage, about waist-high corn, it takes 85 to 90 growing degree days for each leaf to develop. However, in their youth, after V10 stage, corn plants pick up speed and add new leaves every 50 to 60 GDDs. At this stage, corn grows so fast that you can almost see it grow.
Corn needs special attention during critical stages to attain higher yields.
Micro- vs. macroenvironment
In a corn plot in the past, Tom J. Bechman, editor of Indiana Prairie Farmer, and I saw plants in outer rows with 10 to 12 ears — including the main stalk, tillers and tassel ears. These plants were trying to make maximum use of their microenvironment and make as large a progeny as they could. In the same field, we saw plants with nubbins because of overcrowding due to double planting.
This is an excellent example of the effect of microenvironment. This field yielded more than 226 bushels per acre because of a great macroenvironment. Macroenvironment refers to the overall favorable growing conditions for the entire field, not just end rows or crowded spots, during the entire season.
During the waist-high stage, the corn plant is already deciding how many rows of kernels it can put on. Kernel rows are always an even number and primarily controlled by hybrid genetics. But environmental factors such as plant density, water and nutrient availability, heat, and drought can influence row numbers. Deviation up or down will always be in pairs. Depending on the field conditions, a couple of rows may be added or subtracted from the hybrid genetic potential.
After the seedling stage, the most critical phase in the life of a corn plant is the pollination period. Make sure that insects such as Japanese beetles or rootworm beetles in conventional corn aren’t clipping silks. Check with your chemical dealer and use suitable insecticides to control these pests.
The pollination stage is when the plant determines how many kernels it can grow per ear. If it has sufficient water and plenty of nutrients, with temperatures in the mid-80s during the day and mid-60s during the night, it may extend the ear length if it is a flex-eared hybrid.
In my corn breeding days, I developed a couple of widely grown hybrids that combined the genetic qualities of both flex- and girthy-eared hybrids. It’s a rare combination and a plant breeder’s dream that requires extensive research and testing. Individual plants can increase the number of kernels at the ear tips under favorable conditions.
Let’s hope we have a good pollination season. After giving us a tough planting season, Mother Nature needs to give us a break during the rest of the growing season.
Nanda is director of genetics for Seed Genetics-Direct, Jeffersonville, Ohio. Email firstname.lastname@example.org or call 317-910-9876.