BASF sponsored a virtual press conference recently to make growers more aware of potential soybean cyst nematode problems. Panelists included Kaitlyn Bissonnette, Extension plant pathologist with the University of Missouri, and Troy Bauer, a technical rep with BASF.
Here is key discussion from the event:
What is the first step in managing soybean cyst nematodes?
Bissonnette: Pulling soil samples is critical. I call it “step zero” because unless you know you have soybean cyst nematode in a field and how many eggs are present, you don’t have a good starting point for developing a management plan.
When is the best time to sample for SCN?
Bissonnette: The absolute best time is right after soybean harvest in the fall. We recommend breaking the field up into zones based on soils and topography and pulling a composite soil sample from each zone.
When is the next best time to sample?
Bissonnette: Fall is best, but if that doesn’t happen, pull them in the spring before planting. Nematodes go dormant in the winter.
How widespread is the problem?
Bauer: The SCN Coalition reports that nematodes can be found in almost every county in the “I” states, and in adjoining states throughout the Midwest. The pest continues to spread and is now in some counties in Kansas, the Dakotas and in New York.
If someone farms on the edge of where SCN is documented, should they still sample?
Bissonnette: Yes. Nematodes travel on farm equipment, boots and in about any way soil moves. If you don’t find them, sample again in three years. Keep monitoring the situation.
If you know they’re in your fields, how do you manage them?
Bissonnette: The lab will report if numbers are low, medium or high. The higher the numbers, the more intensely you need to manage. Rotate to non-host crops, like corn and wheat, and strive for good weed control. Many weeds are hosts.
Select SCN-resistant varieties. Not all SCN resistance is created equal. Soybean cyst nematodes are overcoming some forms of resistance, especially the PI 88788 type. If so, ask for varieties with Peking-type resistance. A newer type of resistance is just becoming available, and so far, is limited to shorter-season varieties. Within varieties with PI 88788 resistance, some varieties allow SCN to build up numbers during the season more than other varieties. Work with your seedsman.
You may also want to consider layering in seed treatments to help provide control of SCN.
What types of SCN seed treatments exist?
Bauer: There are two main types: chemical seed treatments and biological seed treatments. Ilevo is an example of a chemical seed treatment. Votivo is a biological-based seed treatment.
How long will protection from a chemical seed treatment last?
Bauer: It will vary based on the individual product. We know that Ilevo provides very strong protection for 30 days after planting, and still provides pretty good protection for another 30 days against soybean cyst nematodes.