Battle for the Belt: Season 4, Episode 6 – Corn Staging

Season 4, Episode 6 of Battle for the Belt is now available: 

In Episode 6, we discuss the importance of monitoring corn growth and development through proper crop staging. Accurate staging directly impacts key practices such as fertilizer timing and herbicide applications, and can help us understand overall crop performance.

The correct way to determine the vegetative stage of a corn plant is by counting all leaves with a visible collar, including the first rounded leaf. As the season progresses, lower leaves get lost, and adequate staging can become difficult. Three common methods can be used to determine corn vegetative stages:

1. The split-stalk method: during later vegetative stages, lower leaves may have senesced or fallen off, making it difficult to count visible leaf collars. In this case, the stalk can be split lengthwise, and the nodes can be counted. Each node is associated with one leaf, except for the first set of nodes at the base of the plant (1-4), with the first visible separated node being node 5. From that point, the vegetative stage can be estimated by counting nodes up to the last developed leaf (visible collar).
2. The paint-leaf method: this consists of marking leaves along the corn plant. For practicality, we normally mark/paint leaves 5, 10, and 15 if needed (Figure 1). Since leaves continue to senesce later in the season, multiple paintings might be necessary. Having these indicators in the fields would facilitate appropriate staging later in the season.
3. The growing degree day (GDD) method: The growth of a corn plant is directly related to the accumulation of heat units over time rather than the number of calendar days from planting. The GDD system provides information for estimating crop stages, given site-specific conditions throughout the season (e.g., daily temperatures), and planting dates. We know approximately how many GDDs are required for a corn plant to produce each new leaf. Leaf appearance generally requires more accumulated GDDs early in the season and fewer GDDs later in the season as temperatures increase and plant development accelerates. It normally takes about 82 GDD for an early corn plant to put each new leaf, from emergence to about the V10 stage. From that point forward, a corn plant needs fewer GDDs for each leaf. Learn more about the GDD method here!

Field Progress Update

At the Northwest Agricultural Research Station, we are targeting to establish the fourth planting date this week. With this, all three experimental stations will have completed their first four planting dates. In the Wooster site, the corn crop from planting dates 1, 2, and 3 was at the V5, V3, and V2 stages, respectively (Figure 2). All other planting dates and crop stage information are presented in Tables 1 and 2. 

Keep following ‘Battle for the Belt 2.0’ this growing season to learn more and get further updates! You can find the full video playlist of Battle for the Belt on the Ohio State Agronomy YouTube channel.