Tips for Preventing Soybean Seedling Diseases

Post-planting is an ideal time to begin early season crop scouting. Many soilborne pathogens strike as soon as the seed begins to take on water; others strike young seedlings.

While walking fields this spring, I’ve noticed everything from poor stand counts caused by inadequate seedbed preparation, soil compaction or soil crusting. All of these situations can promote seedling diseases. Understanding the symptoms of common diseases and diagnosing the problems will help you manage these diseases in the future.

The first step in combating soybean seedling disease is to choose high quality soybean seed. There’s a reason “quality” is literally stamped on each bag of Latham® High-Tech Soybeans. The Latham family has nearly 70 years of experience, producing the highest quality seed. Also be sure to check disease ratings in the seed product catalogs.

The second step to achieving higher soybean yields is seed treatment. Recently released research results show seed treatment is the best defense against seedling disease. Choose a seed treatment like Latham’s proprietary SoyShield® fungicide and SoyShield Plus, a fungicide-insecticide combination. It’s especially important to protect early-planted soybeans from seedling diseases and insects.

While it stands to reason that earlier-planted soybeans will have more potential for yield due to greater access to sunlight, there are risks associated with early planting. Plant in fit conditions to set up your crop for success. Optimal planting conditions for soybeans include dry soils that are consistently 60 degrees at planting time. Soybeans are a light-sensitive crop, so yields are strongly influenced by the amount of solar radiation the crop receives throughout the growing season.

Learn what you can this season to increase soybean yields in the future. If there’s an area where seedlings aren’t emerging, dig into the soils and see what’s happening underground. Some pathogens attack the seed. Some seeds are killed before germination. You may notice rotting seeds. Sometimes “damping off” occurs right before or right after emergence.

There are three main categories of seedling diseases: seed rot, seedling mortality, and root or lower stem decay. Watch for these in 2014:

• Seed rot occurs during the VO-VE growth stages and may be caused by three pathogens; Pythium, Phytophthora, and Phomopsis. Typical symptoms are soft decay of seed, missing seedlings in the row or poor emergence.
• Seedling Mortality, commonly damping-off or seedling blight, occurs during the VE-V4 growth stages. Pythium, Phytophthora, and Rhizoctonia, can cause seedling mortality.
• Root or lower stem decay may take place during the seedling stage or may not be apparent until later reproductive stages (VE-Rn). Pathogens that cause root stem decay during the seedling stage are the same as those that cause seedling mortality.