What Are Nematodes?

Nematodes are microscopic roundworms that live in the soil and feed on plant roots, stealing water, weakening the plant, and ultimately reducing yield potential.

What causes SCN in soybeans?

 Damage is caused when nematodes enter the roots and establish feeding sites that steal nutrients and water from the plant. Wounds created by feeding can cause cell death and weaken the plant. Damage increases as nematodes develop into adults and approach the reproductive stage. Cysts containing hundreds of eggs form after mating, leading to an explosion in the number of nematodes. This underground cycle can be repeated 3-6 times during a single growing season. Soybean cyst nematodes are present in nearly all soybean geographies, with root-knot and reniform nematodes also reducing yields in the South.

SCN Symptoms

Because the damage occurs below ground, nematodes can cause up to a 30% loss in soybean yield before you see any symptoms.

Identifying SCN in soybeans

Sometimes you may catch a stunting and yellowing of the crop, but scouting is the best method of identifying SCN. There are two ways to scout for SCN. First, dig (don’t pull) roots and look for females. Second, collect soil samples for testing. It’s important to test your fields to know your SCN numbers, because egg populations can build rapidly.

When to sample:

• In a non-host crop – Fall

• In soybean stubble – Fall

• Before a soybean crop – Spring

• In the soybean crop root zone – During the season

How to sample:

• In soybean stubble – Fall

• In soybean stubble – Fall

• In soybean stubble – Fall

• In soybean stubble – Fall

Soybean Cyst Nematode Management & Protocol

To manage SCN, it’s important to choose resistant soybean varieties, rotate to nonhost crops like corn or wheat, and use a nematicide-containing seed treatment like ILEVO seed treatment.

Why ILEVO seed treatment?

Unlike other products, it has broad-spectrum nematicidal activity that leads to direct mortality across the nematode lifecycle. ILEVO seed treatment limits the impact of reproduction and reduces damage to the plant that’s caused by nematode feeding.

At least 80% of acres with Sudden Death Syndrome (SDS) are also impacted by SCN, so it’s imperative that you choose a seed treatment that’s effective against both pests. Maximize your yield potential with ILEVO seed treatment, the proven winner against both SDS and nematodes. 

*SCN Coalition grower yield loss estimate of 5.1 bu/A, estimated at $14/bu commodity price.

Causes of SDS in Soybeans

SDS is caused by the soilborne fungus Fusarium virguliforme, which is one of the most aggressive soybean root rot pathogens.

How it damages soybeans:

SDS develops in compacted soil during cool, wet weather conditions. More moisture in the soil for long periods of time enables the fungus to penetrate the root system and put stress on the soybean plant. The fungus produces toxins that lead to foliar destruction, leaf drop, and aborted pods. Initial SDS infections occur onthe roots and crowns of young plants, which impact their early-season health.

How it impacts farmers:

Over the last five years, average annual damage has cost soybean growers more than 44 million bushels in lost yield, and it continues to clilmb. SDS spreads from field to field through soil movement and can survive and overwinter in crop residue. So, once it's in a field, it stays there.

Identifying SDS

There are many symptoms you may notice in your soybean plants that will help you identify SDS in your fields. 

SDS Symptoms:

• Leaf drop and aborted pods

• Plants may pull easily from the soil

• Soybean roots may have a blue coloration

• Internal tissue of the main root will appear gray to reddish brown (a healthy root is white)

• Soybean stem tissue turns white while areas between leaf veins turn from bright yellow to brown

• The brown tissue may fall out and leave large holes in the leaves

• Leaf blades will fall off the petioles (the thin “stems” connecting leaf blades to the main stem) while the petioles remain attached 

Keep in mind that symptom severity and toxin production will vary by climate and level of SDS resistance in soybean varieties. Additionally, root rot effects can still contribute to yield loss even if SDS symptoms aren't present.

Sudden Death Syndrome Management and Protocol

Manage SDS and protect yields through an integrated approach that includes soil drainage improvements on problem fields, as well as a seed treatment like ILEVO seed treatment.

Why ILEVO Seed Treatment?

ILEVO seed treatment is the most complete SDS protection available on the market, because it protects against both the root rot (below-ground) and foliar (above-ground) phases of Sudden Death Syndrome. It controls early-season root rot at the initial infection site before symptoms are visible, reducing the incidence and severity later in the season. Additionally, ILEVO seed treatment’s yield advantage only increases with higher levels of foliar SDS symptoms (2-10 bu/A higher).

When Soybean Cyst Nematode (SCN) is present in the field, it can exacerbate SDS. Thankfully, ILEVO seed treatment provides broad-spectrum protection against all plant-parasitic nematode species in the seed zone. For over 10 years, yield gain results have proven that ILEVO seed treatment wins against both SDS and SCN.

Active SCN management starts with proven winners. That’s why we partner with our friends at The SCN Coalition every October to help farmers #GrowInTheKnow. From free soil test kits to informational videos and resources, we’ve got everything you need to topple the ‘todes!

Recognizing the Halo Effect

The Halo Effect first appears as a light green, then changes to yellow, and finally to brown. The color change is limited to the cotyledons and won’t appear on the unifoliates or trifoliates.

What is it?

The Halo Effect is an indication that ILEVO seed treatment is being localized in the root and seedling where it’s needed for protection against nematodes and the SDS fungus.

SDS is caused by the soilborne fungus Fusarium virguliforme, which is one of the most aggressive soybean root rot pathogens.

It Doesn’t Last Long

The Halo Effect only appears on the cotyledons and remains there until they fall off. Unifoliates and trifoliates of the young soybean plant will emerge normal in color and growth.

Effect on emergence, plant stands, and yield::

The Halo Effect has no detrimental impact on the speed of emergence, plant stands, or yield. After three years of field testing, soybeans treated with ILEVO seed treatment were proven to emerge at the same speed as untreated beans. Trials also showed a yield increase of 2-10 bushels per acre compared to fungicide/insecticide seed treatment package.

Response to herbicides:

A two-year study in Indiana and Iowa found no interaction between the Halo Effect and preemergence herbicides. ILEVO seed treatment didn’t increase the potential for seedling damage from herbicides, and preemergence herbicides didn’t make ILEVO seed treatment less effective. 

Growth Response

In some instances, you may initially see a slower growth response as the soybean plant begins to process or metabolize ILEVO seed treatment, but that’s a good thing.

What that means for your crop:

The slower growth gives the developing soybean plant more time to build up its internal resistance to SDS, effectively jump-starting the plant’s defense response, similar to how the human body reacts to vaccines. Twenty or thirty days after emergence, you’ll begin to see a healthier-looking plant compared to untreated soybeans. 

Identifying SDS

There are many symptoms you may notice in your soybean plants that will help you identify SDS in your fields. 

• Sudden Death Syndrome (caused by Fusarium virguliforme)

• Septoria Brown Spot (early season) (Septoria glycines)

• Soilborne nematodes: Lance nematodes (Hoplolaimus spp.)

• Reinform nematode (Rotylenchulus reniformis)

• Root-knot nematode (Meloidogyne incognita)

• Root lesion nematode (Pratylenchus spp.)

See ‘Labels and MSDS’ below for special or state-labeled pests.