If you farmed in the 1960s or 1970s, treating soybeans to many farmers meant opening the seed box, pouring on a black powder and stirring it in with a stick or whatever was handy. You were adding an inoculant so that bacteria would promote development of nodules on the roots. It was extremely important in fields where soybeans hadn't been grown many times. Many people still use inoculants and believe it adds yield today.
Today, however, 'seed treatment' usually means planting seed that came with a treatment applied at the seed plant. But just asking for treated seed or knowing you're buying treated soybean seed isn't enough, most experts say. You need to know what it is treated with.
About 90% of the soybeans that Syngenta sells this year will be treated, says Mark Lawson, a technical specialist with Syngenta, based at Danville. Most of it is treated with what the company considers is its top of the line treatment – CruiserMaxx. It contains an insecticide and fungicides.
It may also contain a new seed treatment called Vibrance, Lawson notes. This is brand new chemistry, available commercially for the first time this spring.
"It controls rhizoctonia root rot," he explains. That's the disease that can invade plants when they are young. Tell-tale symptoms are red lesions on the plant near the soil line, root rot and seed rot. It can cause yield losses if the infestation of Rhizoctonia is severe and enough plants are killed or stunted.
Soybeans often survive but don't get off to a good start. "We're glad to have a product finally that can address rhizoctonia root rot as well," Lawson concludes.
Ingredients in the CruiserMaxx treatment should be able to handle phytopthora root rot. It takes different chemistry to control that pathogen. Expect phytophthora to be worse if it stays cool and wet, and if there are depressional soils in the field.