As soybean growers begin another season, ISU Extension Plant Pathologist Alison Robertson says there are four main seedling pathogens to be aware of:
Certainly this year is starting out to favor the Pythium species that are more prevalent in cool, wet soils. While Pythium and Fusarium are usually limited to damaging the early seedling stage of development, Phytophthora can be a season-long problem. I have also noticed that Rhizoctonia can linger in the soils and cause damage at a later time.
Pathogens can start infecting the seed as soon as it begins to take in water, which is the very first step in the process toward germination and emergence. It doesn’t, however, stop there. As that seed continues to absorb water, swell and develop a hypocotyl, pathogens can attack and destroy the seedling even after emergence.
The good news is these four particular soybean pathogens can be managed very well by using seed-applied fungicides like Latham’s SoyShield. Note that Dr. Robertson references using a combination of active ingredients, which is exactly what SoyShield is – and it was specifically designed with that in mind.
Benefits of seed treatments far outweigh the costs. In a wet, cool planting season like this, fungicide-treated seed is a must to prevent damping off from Pythium, Rhizoctonia, Phytopthora and Fusarium.