Mother Nature wasn’t very kind during the last two growing seasons. We had a tough time during the harvest season of 2018 with lots of rain. Some crops couldn’t be harvested until January 2019. To add insult to injury, she didn’t cooperate during planting season last year either. Many growers created soil compaction while mudding seed into the soil.
However, many growers still ended up with decent yields. We know corn is one of the most efficient agricultural plants. It’s a fantastic factory for using resources supplied by nature. The grower who understands the development of the plant can profit by selecting the right hybrids, fertilization practices and cultural methods, and by controlling localized disease and insect pests in a timely fashion.
Even though we’ve managed later plantings successfully, date of planting is still very important for getting higher yields. In most years, you want to plant corn before the middle of May. This allows you to maximize the use of solar energy for making sugars and starches, and increases chances of getting higher yields.
It’s important to know the early stages of development, because establishing good plant stands is so critical. Unlike soybeans, corn doesn’t develop more branches and compensate for big gaps. So, you must plant the appropriate number of corn seeds to have the desired stands that meet with your yield goal, soil type, soil fertility and water availability.
Understand the corn plant
Let’s try to understand what happens in the seedling stages of the corn plant. If you know the growth stages of corn, it permits you to plan better for field operations and manage the crop.
The first sign of corn emergence is the appearance of a tip that breaks through the ground. We call it the coleoptile. It pierces through the ground like a spear and starts to elongate. We need 100 to 120 growing degree days to accumulate from planting to seedling emergence.
The growing point is about 1 or 1.5 inches below the ground. This stage is called the VE stage. The growing point stays below ground for three to four weeks and is protected from frost or insects on the surface.
Most hybrids will eventually produce 18 to 22 leaves, depending upon their relative maturity. How do we measure the stage of maturity of a corn crop?
The most common method of staging the corn plant is the collar method. Count the number of leaves with collars, which develop when the leaf partially unclasps from the stem. A leaf collar is the light-colored band at the base of the leaf. This method includes the first emerging round-tipped leaf as the first leaf.
Meanwhile, the root system, consisting of radical and seminal roots, develops to supply water and nutrients to the young, fast-emerging seedling. Secondary roots, known as nodal roots, soon start. These grow from the nodes below the ground.
Four nodes develop below the ground. Generally, the first node above the ground is the fifth node. We will follow along the development of a corn plant as the season progresses.
Nanda is director of fenetics for Seed Genetics Direct, Jeffersonville, Ohio. Email him at firstname.lastname@example.org or call him at 317-910-9876.