Soybean Cyst Nematode

Soybean cyst nematode is often forgotten, difficult to identify at first glance and one of the most destructive pests to soybeans. SCN varies case by case, but with testing and prevention practices, steps can be taken to help protect soybean fields and help achieve high yield potential.

What Is Soybean Cyst Nematode?

SCN is a microscopic worm that attaches to the soybean root, removing vital nutrients and moisture. It has three stages of life: eggs, juvenile (four stages) and adult. The female adult appears as a lemon-shaped cyst that can be seen growing on the root four to five weeks after planting. The pest can mimic other similar issues found in soybean fields, making it very difficult to diagnose. SCN often goes undetected for years with inconsistent symptoms. Some visible signs such as yellow spots and patches can occur in July or August, and the more yellow or stunted the soybeans are, the more severe the case of SCN is. Visual symptoms are often more prominent in drier seasons. In good growing conditions, symptoms may not appear. If you notice yield is decreasing in various areas of the field, try testing for SCN. In areas highly infested with SCN, plants have been known to die before flowering. Sometimes, even if the whole field is infected, SCN may only be seen in certain spots. When left untreated, SCN is very damaging and can weaken the plant, allowing disease and other pathogens to take control. It is almost impossible to eliminate SCN, but there are key steps we can take to control the spread of the pest.

What Can I Do to Prevent Soybean Cyst Nematode?

Testing to identify SCN is crucial. Test fields in 5- to 10-acre sections for SCN with a soil probe. Sample roots from various areas, including trouble spots and equipment entry points. Make sure the root zone is being reached and samples are consistent.

Once present, however, SCN cannot be eradicated. Certain practices can be implemented to keep the pest contained and infestation low. It’s very important to choose soybean varieties with good ratings for SCN resistance, such as Asgrow® soybean products with exclusive genetics and strong defensive traits. Early season prevention is important to ensure soybean roots are uninviting to the pest by including a seed treatment to fight against SCN. Maintaining plant health with proper fertility and fungicides, such as Delaro® Complete fungicide, is also critical. Damage can be subsided if plants are receiving adequate nutrients and plenty of water to supplement pest feeding. When SCN is already present, crop rotation practices can be considered and introducing crops like corn or wheat eliminate the food source for the pest. However, eggs can stay alive for multiple years, so crop rotation is often not a solid solution. In cooler seasons, weed management plays a large role in the growth of SCN. 

For more information specific to your area, speak with your local DEKALB® and Asgrow® seed representative. 

ALWAYS READ AND FOLLOW PESTICIDE LABEL DIRECTIONS. Performance may vary, from location to location and from year to year, as local growing, soil and weather conditions may vary. Growers should evaluate data from multiple locations and years whenever possible and should consider the impacts of these conditions on the grower’s fields. 

Not all products are registered in all states and may be subject to use restrictions. The distribution, sale, or use of an unregistered pesticide is a violation of federal and/or state law and is strictly prohibited. Check with your local dealer or representative for the product registration status in your state. Asgrow and the A Design®, Bayer, Bayer Cross, DEKALB and Design® and Delaro® are registered trademarks of Bayer Group. ©2021 Bayer Group. All Rights Reserved.


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