Agronomy Talk

Agronomy Update

Emergence and Growth Stage Updates for Corn, Soybeans and Wheat

Published on Thursday, May 7, 2015

Other than cool soil temperatures during much of April, most farmers experienced near ideal soil conditions (moisture and texture) for planting corn. For April-planted corn, 10-15 days to emergence has been a common range. As of May 6, all the corn I have looked at that was planted on or before April 24, has emerged. If you have corn that was planted in April, that has been in the ground for more than 14 days and has not yet emerged, a field visit may be necessary to determine the cause and evaluate the potential need for replant.

As corn begins to emerge and progress through early vegetative stages (i.e. V3-V4), maintaining a healthy mesocotyl is important for seedling vigor and survival. The Escalate™ yield enhancement system for corn includes seed-applied fungicides that help protect against seedling fungal pathogens like Pythium and Fusarium. If prolonged periods of cool and wet soil conditions persist throughout the early seedling stages, seedling blights could appear. With warm temperatures and drier soil conditions, however, look for mesocotyls that are light-colored and healthy, as seen in Figure 1. It’s important to remember that until about V4, the mesocotyl is still a major portion of the nutrient transport highway that sends carbohydrates from the seed to above-ground plant tissue. By V4, the nodal root system should have a good start and will soon become the primary root system for the plant.

Figure 1. A corn seedling, Beck’s XL 5828AMX™*, with a healthy mesocotyl (indicated by tip of green pointer). The tip of the knife blade indicates where the nodal root system should begin developing by V3-V4.

Some farmers throughout the area got started planting soybeans the last week of April. While high yields can come from early-planted soybeans, there is greater potential risk associated with many seedling diseases and also infection by Fusarium virguliforme, the causal agent of Sudden Death Syndrome (SDS). In addition, the overwintering population of bean leaf beetle can be a concern with early-planted soybeans. Another major risk includes the greater potential for plant death from a frost event in May after emergence, which would require replanting. Despite these risks, some chose to take advantage of the good soil conditions and protection with seed treatments such Escalate to get some soybeans planted.

As soybeans begin to emerge, the hypocotyl arch (as seen in Figure 2) will first appear in the slot where the seed was planted, followed by the cotyledons (aka, “seed leaves”). This is a critical stage for stand establishment and early plant development. Cool, wet conditions that promote fungal pathogens are hopefully minimized during this stage. Escalate can help protect against many of the fungal pathogens that can reduce stand establishment. This is also an important growth stage to be aware of for many soybean herbicides. Labels of many commonly-used effective residual herbicides are restricted to application prior to the hypocotyl arch appearing in the seed slot. Be sure to check labels for any restrictions prior to application.

Figure 2. An emerging soybean seedling, Beck’s XL 345R4™*, with a healthy hypocotyl arch (at tip of knife blade).

WHEAT STAGE (Herbicides & Fungicides)
Most of the wheat across my geography that was planted on or before October 21, 2014 has reached Feekes 7 growth stage or later. This stage can be identified by carefully stripping leaves off the main stem and seeing two nodes on the main stem (Figure 3). At this stage, the stem can be split and the developing grain head can be found just above the 2nd node (Figure 4).

Feekes 7 is an important growth stage for many reasons:

1. It helps predict flag leaf emergence, which occurs 5-10 days after Feekes 7. This can help time scouting for leaf diseases and the potential need for a fungicide such as TwinLine®, Quilt Xcel®, or Stratego® YLD.

2. It helps determine remaining available weed control options (Figure 5). Depending on your cropping system and weeds present, I usually recommend Buctril® if the plan is to double-crop beans after wheat harvest. If soybeans will not be double-cropped after wheat harvest, I usually recommend Harmony® Extra, Huskie®, or Stinger®. Don’t forget to consider rotational restrictions if you will be seeding cover crops after wheat harvest.

Figure 3. A wheat plant, BECK 129, at Feekes 7 growth stage. Two nodes appear, one at 2 in. and another at 5 in. above the soil line.

Figure 4. A split wheat stem of BECK 129 at Feekes 7. The green pointer indicates the 2nd node, while the knife tip shows the developing grain head inside the stem.


Figure 5. Feekes scale of winter wheat stages and herbicide application timings. (Table courtesy of Purdue University, Spring Herbicide Applications on Winter Wheat, 2012.)

Escalate is a trademark of Beck's Superior Hybrids, Inc. *XL® brand seed is distributed by Beck's Superior Hybrids, Inc. XL® and Harmony are registered trademarks of Pioneer. TwinLine is a registered trademark of BASF Corporation. Quilt Xcel is a registered trademark of Syngenta Group Company. Stratego, Huskie and Buctril are registered trademarks of Bayer CropScience. Stinger is a registered trademark of Dow AgroSciences.

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Chad Kalaher
Chad Kalaher>

Chad Kalaher

Beck’s Hybrids team sales agronomist for 22 counties in NE ¼ of IL and 7 counties in NW IN. Raised on grain and livestock farm in southern IL. B.S. Agronomy 1995 – University of Illinois, M.S. Weed Science 1997 – North Carolina State University. Previous positions in seed industry as researc

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Full biography

Beck’s Hybrids team sales agronomist for 22 counties in NE ¼ of IL and 7 counties in NW IN. Raised on grain and livestock farm in southern IL. B.S. Agronomy 1995 – University of Illinois, M.S. Weed Science 1997 – North Carolina State University. Previous positions in seed industry as research agronomist, district, and regional sales manager.


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