April 29, 2020

Agronomy Update: Importance Of Early Scouting, Stages Of Corn And Soybean Emergence

BY Dairyland Seed
Back to Basics 101

It is vitally important to scout fields already planted.  We understand there are hundreds of things going on at the same time in the spring and early summer.  Please scout -- early detection of issues is essential to allow enough time to possibly take corrective action. Don’t wait to look at fields for the first time until you are back in the field with a post herbicide application or at side dress time.  Often, late observance of issues is too late to make wise economic corrective action.  Keep in mind that soils that are 50-55 or less degrees may delay emergence up to three weeks. As soils warm to 55+ degrees, emergence may occur within one week.  Pay extra attention to fields that are slow to emerge and determine if it is only slow to emerge due to cold temperatures or if other issues are affecting emergence.

Dig up seedlings and check the plants for following symptoms:

If plants are missing entirely, check to see if you can even find any seed(s) where plants should be. At times, decisions to take corrective action are not easy to make.  The agronomy team is ready to help you with any questions or concerns.

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Soybean Germination

A little Soybean Physiology 101 as you await soybean emergence:

Courtesy “How a Soybean Plant Develops”, Iowa State University

Potential Issues at Germination and Emergence

Courtesy University of Minnesota Extension

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Stages of Corn Emergence

In the last week to 10 days many areas (but not all) have had favorable weather that has allowed farmers to plant corn. A corn seed has a few processes that it needs to accomplish prior to soil emergence. One of the processes is germination, which takes place when a seed takes in or imbibes roughly 30% of its weight in water, during this process the seed will swell slightly. In most instances germination or seed swelling takes roughly 10-20 Growing Degree Units (GDU’s). (This is shown below and on the left.)

Once germination has initiated, the radicle root will start to emerge, it normally takes 30-40 GDU’s for the radicle root to emerge. (This is shown in the photo above and on the right). The radical always emerges from the tip of the embryo and will orient itself due to gravity so it is growing down, regardless of where the embryo of the seed is pointed, the ability of the plant to sense gravity is called Gravitropism or Geotropism.

The next process to take place is for the coleoptile to emerge from the seed (as shown below and on the left). It normally takes 50-60 GDU’s for the coleoptile to emerge from the seed. Starting between 60-70 GDU’s, the seminal root system will start to emerge from the seed and almost immediately start taking in water and nutrients for the plant to continue to grow. The seminal root system and the radicle will anchor the plant and act as the main root system for the plant until VE (shoot/spike coleoptile emergence) and will continue to grow until V3 (three collared corn).

It normally takes 100-150 GDU’s for the coleoptile to emerge (VE) from the soil surface, (as shown above and on the right) with weather conditions and genetic makeup being factors affecting this process. At VE, the coleoptile will cease to elongate and the foliage that follows will be the embryonic leaves.

Plant / Leaf Stage

Growth Stage

GDU's

Germination

10 to 20

Radicle Root Emergence

30 to 40

Coleoptile Emergence Seed

50 to 60

Seminal Root Emergence

60 to 70

Coleoptile Emergence Soil

VE

100 to 150

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Corteva Technology Use Agreements

All growers with orders for any Corteva Agriscience brand seed product, regardless of crop or trait (including non-GM products) need to have a signed Corteva Technology Use Agreement in place by September 1. Growers should sign the Corteva Technology Use Agreement electronically at www.agcelerate.com. Signing electronically is preferable, however, paper copies are available at www.traitstewardship.com.

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Brian Weller
Western Region
507.456.3034
Dan Ritter
Central Region
219.863.0583
Branden Furseth
Northern Region
608.513.4265
Rod King
Eastern Region
574.596.6721
Terry Jones
Eastern Region
419.630.3115

enjoying our Agronomy Updates?  suggestions for topics you'd like us to weigh in on?  Drop us an email at dairylandseed@dairylandseed.com.  We'd love to hear from you!
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