How long does it take for Biocontrol Nematodes to impact rootworm in the field?

• Biocontrol Nematodes do not achieve full activity until the second growing season after application. The level of activity in year 1 is influenced by the method of application (pivot vs sprayer), length of time between application and rootworm hatch, and the level of soil moisture during the rootworm larval period(June-early July).  

• With a May application, the year 1 activity level will range between 60% and 80% of full activity.  This activity level will rise to 100% for the second growing season.

• Since rootworm typically hatch around June 1st, a Biocontrol Nematode application in early May will typically have a bigger year 1 impact on rootworm than a late May application.

• This is because of the Biocontrol Nematodes have more time to move throughout the soil profile before rootworm egg hatch.

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What yield recovery should I expect using Biocontrol Nematodes with my failing RW trait?

• Farmer field trials indicate yield recovery from increased rootworm control with Biocontrol Nematodes ranges from 6 bu/ac to 15+ bu/ac in the year of application (first year).

• The level of yield recovery is dependent on the timing of the application, soil moisture conditions, method of application and the level of rootworm pressure in the field.  

• Second year yield recovery is dependent on the level of year 1 yield recovery and the level of reduction of rootworm feeding the first year.

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How much reduction in root feeding should I expect?

• With an early-mid May Biocontrol Nematode application, farmers should see a major reduction in root feeding damage throughout the field.  

• There will remain some rootworm hotspots where the rootworm females dumped a lot of eggs the previous fall and the Biocontrol Nematodes have not “caught up” to the high level of rootworm larvae.  

• In year 2, a majority of these “hotspots” will have disappeared but there still may be a few under extremely high rootworm pressure.  

• By year 3 after inoculation, all the hotspots should disappear.

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What is the best application window for Biocontrol Nematodes to achieve the best rootworm control?

• Persistent Biocontrol Nematodes have a wide application window due their ability to persist across long periods when host insects(prey) are not present.  

• The longer time between the application of Biocontrol Nematodes and the presence of the target insect, the better the year 1 activity.

• As an example, rootworm typically hatches around June 1.  An early May application usually results in better year 1 control than a late-May application.  

• Recent field data also shows that a Biocontrol Nematode application the previous September results in a significantbetter year 1 activity against rootworm than an early May application.

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Should I use a soil insecticide with my traited corn in the year of application of BC nematodes?

• Since year 1 activity of Biocontrol Nematodes ranges from 60%-80%, the use of a soil insecticide at planting frequently has benefit for the farmer by increasing the yield recovery for reduced root damage.

Does Biocontrol nematodes benefit traits which are not failing as much as failing traits?

• The beneficial role of Biocontrol Nematodes changes when used with a failing RW trait vs a RW trait which is newly introduced or still providing a good level of root protection.

• With the failing RW trait, the presence of Biocontrol Nematodes reduces the level of rootworm feeding damage and there is a yield recovery from the reduced root damage.  

• For a  fully functioning RW trait, Biocontrol Nematodes target the survivors of the RW trait (yes, there are survivors), resulting in a delay of the rootworm resistance development and an increased durability of the RW trait. Said simply, Biocontrol Nematodes enable a RW trait to last longer before resistance emerges.