Farmers paying attention to resistance management realize stewardship is a huge component in protecting the crop technologies they've come to rely on so heavily.
Yesterday's confirmation of Cry3Bb1-resistant populations of western corn rootworms only reinforces this principle. If that weren't enough, Monsanto representatives have been out helping growers navigate through this situation.
Luke Samuel, Monsanto's corn insect traits product development manager, says the key to guarding against Cry3Bb1 resistance is implementation of one of several best management practices they've developed. Option one is simple: maintain a traditional corn/soybean rotation. Easy enough, but many growers are hesitant to switch back to soybeans in the land where corn is king.
Next on the list: consider a hybrid with pyramided rootworm protection, such as Monsanto's Genuity SmartStax. These products typically cost more than triple-stack hybrids, but they come with the added benefit of dual modes of action against corn rootworm and a 5% refuge requirement, which is included in the bag.
For those who don't want to move to a refuge-in-the-bag product, Samuel recommends using a soil insecticide in conjunction with a product that has a single Bt trait for rootworm protection.
"We want to make sure we're stewarding these rootworm technologies properly," Samuel notes. "With multiple modes of action and refuge in the bag, SmartStax is a big part of this."
Monsanto also notes the data assessing their BMP approach has demonstrated that farmers can manage rootworm resistance issues. Additionally, they note fewer performance-related inquiries have been made this year regarding rootworm traits than last year.
Lastly, Samuel says corn rootworm populations typically don't travel very far and can be effectively managed by implementing BMPs.
"Corn rootworm management is a field-to-field scenario," he notes. "Rootworms don't move very far. Generally, where they hatch is where they lay their eggs."
The resistant rootworms were confirmed from two populations collected in northwestern Illinois in Henry and Whiteside Counties last August. University of Illinois' entomologist Mike Gray reported the results yesterday at Agronomy Day. The announcement comes a year after Iowa State University's Aaron Gassmann confirmed Cry3Bb1-resistant populations in Iowa.
BMP BREAKDOWN: Monsanto representatives have visited farmers who have reported a loss in Cry3Bb1 effectiveness. This pie chart shows what options they've elected to help maintain rootworm control.