Read the entire report from
our technical services team
Realize optimum corn yields through an integrated management approach for Western Corn Rootworms.
Effective management of Western Corn Rootworm (WCR) begins with an integrated approach that emphasizes stewardship of existing technology. The rotation to non-host crops can be an effective tool for managing corn rootworms but often is not a practical option in some corn growing areas. Bacillus thuringiensis (Bt) traited corn has been effective and highly successful. Unfortunately, planting of pyramided traited Bt corn has been overly relied on and now the protection provided by this technology is not as strong as it first was. To help preserve Bt traited technology corn, the incorporation of other strategies is needed, such as using soil-applied insecticides at planting and foliar insecticide treatments targeted at adult WCR.
SOIL-APPLIED INSECTICIDE TREATMENTS FOR PROTECTION AGAINST WCR LARVAL FEEDING: CAPTURE® LFR® INSECTICIDE AND ETHOS® XB INSECTICIDE/FUNGICIDE
Capture LFR insecticide and Ethos XB insecticide/fungicide help maximize root health at planting with a next-generation, liquid, in-furrow insecticide/fungicide that’s simple to mix with liquid fertilizer and delivers WCR root protection against this yield-robbing pest.
| Product Attributes | Capture LFR insecticide | Ethos XB Insecticide/Fungicide |
|---|---|---|
| Active Ingredients | Bifenthrin | Bifenthrin + Bacillus amyloliquefaciens strain D747 |
| Class | Pyrethroid: IRAC Group 3A | Pyrethroid: IRAC Group 3A & Microbial: FRAC Group 44 |
| Recommended Rates | 8.5 – 17 fl. oz./A | 8.5 – 17 fl. oz./A |
| REI | 12 hours | 12 hours |
| Starter Fertilizer Compatible | Yes | Yes |
| Benefit Provided | Protect roots from larval WCR feeding. | Helps maximize root health at planting and protect roots from larval WCR feeding. |
FOLIAR ADULT INSECTICIDE TREATMENTS TARGETED AT REDUCING GRAVID EGG-LAYING WCR ADULTS: STEWARD® EC INSECTICIDE
Steward® EC insecticide delivers reliable control of adult WCR when applied properly. Primary exposure is through ingestion with some contact activity for increased control levels and moderate residual activity. Adult WCR behaviors are affected (feeding, egg laying and mobility) within zero to four hours of ingestion and this product resists wash off once dried. There is minimal impact to many key beneficial insects and predators and there is no flaring of spider mites. Steward EC insecticide has been formulated to help eliminate mixing, handling and clean up issues and contains both an oil solvent and a surfactant package that provides optimal leaf wetting and surfactant characteristics for excellent crop protection.
| Product Attributes | Steward EC insecticide |
|---|---|
| Active Ingredients | Indoxacarb |
| Class | Oxadiazine: IRAC Group 22 |
| Recommended Rates | 6-10 fl. oz./A |
| REI | 12 hours |
| Benefit Provided | Suppress the number of eggs laid and potential WCR problems in the future. Plus, controls other Lepidopteran pests. |
An effective and properly timed foliar insecticide application of Steward EC Insecticide can suppress the number of eggs laid and reduce potential WCR larval feeding problems in the future. Three factors are important to consider when applying Steward EC insecticide:
- Proper Timing: Treatments are usually started when more than 10% of the females are gravid. It is not advisable to make treatments too early, since more females will emerge to lay eggs and newly emerged silks and foliage will not be protected. It is not advisable to make treatments too late, since egg laying will already be complete.
- Good Coverage: Because this product needs to be consumed, it needs to get to where the adult WCR are feeding. It is recommended that 3-5 gallons/A are applied by aerial applications.
- Proper Rate: Field efficacy trials have shown Steward EC insecticide provides excellent knockdown and control at rates of 6-10 fl. oz./A. If high adult WCR numbers are present and longer residual control is needed, the higher rate should be used.
INTEGRATED APPROACH: SOIL-APPLIED INSECTICIDE TREATMENTS AND ADULT FOLIAR INSECTICIDE TREATMENTS
Soil-applied insecticide treatments, such as Capture LFR insecticide and Ethos XB insecticide/fungicide can provide protection to corn roots and help maximize yields. The research trial below shows that using Ethos XB insecticide/fungicide can decrease root damage to Bt traited corn and conventional corn. In addition, the application of Ethos XB insecticide/fungicide to conventional corn can result in root ratings similar to that of just using Bt traited corn.
COPELAND, KS, SCHMIDT FARM, 2020
Planted: 5/1/20; Hybrids Planted: Pioneer 1828 AM and Pioneer 1828 Q; Evaluated: 8/5/20
| Bt Traited Corn | Ethos XB insecticide/fungicide | Node Injury Scale (0-3) |
|---|---|---|
| Yes | Yes | 0.04 |
| No | Yes | 0.14 |
| Yes | No | 0.36 |
| No | No | 0.74 |
NIS = Node Injury Scale
Economic threshold guidelines:
- If NIS <0.25, no economic loss
- If NIS 0.25-0.75, economic loss dependent
- If NIS > 0.75, economic loss likely
Node Injury Scale: Oleson, J.D., Y. Park, T.M. Nowatzki, and J.J. Tollefson. 2005. J. Econ Entomol. 98(1): 1-8.
Adult foliar applied insecticide treatments such as Steward EC insecticide can drastically reduce WCR egg numbers and ultimately larvae the following year. The research trial below shows a Steward EC insecticide application made the prior year can reduce larval feeding in conventional corn to similar levels of just using Bt traited corn.
IOWA STATE UNIVERSITY, DR. GASSMANN, JOHNSON FARM, AMES, IA, 2020
Planted: 5/1/20; Hybrids Planted: Syngenta N63R GT and N63R 3122; Evaluated: 7/27/20
The Steward EC insecticide application applied the prior year, resulted in the conventional hybrid root ratings looking similar to the Bt traited hybrid the following year.
Capture LFR insecticide and Ethos XB insecticide/fungicide are Restricted Use Pesticides. Always read and follow all label directions, precautions and restrictions for use. Some products may not be registered for sale or use in all states. FMC, the FMC logo, Capture, Ethos, LFR and Steward are trademarks and HatchTrak is a service mark of FMC Corporation or an affiliate. ©2021 FMC Corporation. All rights reserved. 21-FMC-2843 07/21
