There was a whole lot of agronomy discussed during this month’s Iowa State University (ISU) Integrated Crop Management conference. Here are a few things Extension specialists discussed.

Mix ‘em up

Using several herbicide modes of action in a weed control program is a good component of a diversified program. One hurdle to this, though, is the perception it will cost more money.

On the industry front, Monsanto (Roundup’s manufacturer) is working with companies like Valent and FMC to offer financial incentives for use of FMC and Valent preemergence herbicides with postemergence Roundup applications in the Roundup Ready program.

“The biggest impediment to diversification is the thought that it is costing farmers money to buy another herbicide,” says Mike Owen, ISU Extension weeds specialist. Incentivizing farmers to use preemergence products with Roundup in Roundup Ready systems helps make it more palatable costwise, adds Owen.

For applicators, splitting between preemergence and postemergence applications also helps reduce time crunches by widening the application window, he adds.

Dealing with resistance to SCN resistance

You’ve probably read about or even encountered soybean cyst nematodes (SCN) that resist SCN-resistant varieties. SCN resistance is highly concentrated in the PI 88788 resistance source. Soybean farmers who have encountered SCN resistance to varieties with the PI88788 source might consider other resistant varieties with different resistance  sources, such as Peking or Hartwing.

Still, planting alternative resistant source varieties is no guarantee they’ll outyield PI88788 resistance source varieties. Some ISU tests show varieties with alternative resistance sources as the highest yielders in SCN-infested soils. Conversely, varieties with the PI88788 resistance source have been top yielders in other trials.