A Tissue for the Issue: Optimizing Corn Growth Stages

A look into impressive V5 corn tissue samples results using soil probiotics

By: David Dyson, Locus AG Lead Agronomist

As my three sons were growing up, unavoidable teenage angst would inevitably creep into discussions. During those moments, a popular saying was to ask if they needed “a tissue for the issue”. Unlike dealing with teenagers, a corn plant does not talk back; but the need for a tissue is still there. That’s because the best way to gauge how the corn crop is progressing during the season is to pull tissue samples.

There are three critical corn growing stages in a plant’s lifecycle:

1. V5 corn growth stage
2. V9 corn growth stage
3. VT corn growth stage

If you are going to pull tissue samples, these are the corn growing stages to perform such testing.

How to determine corn growth stages

Before we can talk about tissue sampling, let’s outline how to determine the different corn growth stages. One method is by evaluating the corn leaves following these steps:

STEP 1: Find the first corn leaf. The first leaf of a corn plant is always a rounded leaf (figure 1). Finding this corn leaf will make the job of staging considerably easier.

This picture taken in 2022 in northern Indiana shows the first corn leaf of the plant to the left of the picture. As you can see, the first corn leaf is always rounded on the tip.

STEP 2: Find the next staged corn leaf. After you find the rounded leaf, advance up the stalk and locate a white collar at the base of the leaf (figure 2). This will be the next staged corn leaf.

This picture from AGWeb.com shows the white collars that determine the individual corn growth stages.

STEP 3: Count the number of staged corn leaves. Each stage will correspond to the number following the “V”. If you want to find V5 corn stage, look for the rounded leaf and count four more collard leaves.

V5 corn stage is the most important

Out of the three critical corn stages, the V5 stage is the most important stage. During the V5 corn stage, the corn plant will determine the maximum rows around the ear. You may be thinking reducing the rows around the ear from 18 to 16 will not make much of a difference. However, if you do the calculations reducing the ear by 2 rows could lose you 20 bu/ac. When December corn is trading around $6.50/bu, 20 bushels adds up to a $130/ac reduction in revenue!

Maximizing yield in the V5 corn stage

To maximize potential yield, it is important to pack the plant with as many nutrients as possible before the V5 corn stage. The best course of action to accomplish this is through the use of specific endophytic microbial strains. These microbes are found in Locus Agricultural Solutions® (Locus AG) Rhizolizer® Duo soil probiotics.

Rhizolizer Duo contains two strategically selected microbial strains:

1. Trichoderma harzianum

1. Bacillus amyloliquefaciens

Both microbes are endophytic, meaning they colonize and live up inside of the corn plant. These seed treatments create an environment inside the plant that help make nutrients more efficiently absorbed into the corn tissue.

Read more about Locus AG soil probiotics.

Corn tissue sample results with Rhizolizer Duo

The Locus AG agronomy team has been pulling tissue samples for the past month on V5 corn. We have been seeing significant differences between corn seeds treated with Rhizolizer Duo and untreated corn seeds.

In tissue samples from V5 corn growth stage, corn seeds treated with Rhizolizer Duo soil probiotics showed increased potassium, zinc, and boron levels compared to the untreated check. This clears the path to increase the number of potential rows around the ear.

In conclusion, the V5 corn growth stage is a critical time for determining the number of rows around the ear of the corn plant. Making sure the corn plant has more nutrients absorbed into the tissue during this corn growing stage will increase the yield potential.

When the Rhizolizer Duo seed treatment was applied, the V5 corn tissue sample results consistently showed higher potassium, zinc, and boron levels.