It’s hard to believe something no bigger than a pencil eraser has the potential to make or break your year. But that's the power of a soybean seed.
“The full potential of the crop is locked in that seed,” says Bob Kemerait, University of Georgia plant pathologist. “Everything after planting either helps or detracts from it.”
Obstacles to Seeds' Success
Unfortunately, there are many factors working against your soybean seeds. Fungi see those seeds as a great host, insects look at seeds as a tasty meal and microscopic nematodes attack the emerging seedlings. Specific field conditions might warrant seed and seedling protection.
Seed treatment can include fungicides, insecticides and nematicides or a combination of these. “You need to ask yourself: ‘What is my target pest?’ Why am I going to use this product?'” says Phillip Glogoza, University of Minnesota Extension educator for crops.
To answer those questions, you'll want to take into account your soybean field's history. Have you suffered yield loss because of fungi, diseases, insects or nematodes? Did those losses occur during the seedling stages when treatment would be beneficial? What are the other factors, like crop rotation, that might increase risk?
Once you've figured that out, you can start evaluating your seed treatment options.
Many seed companies automatically treat corn seed, but you might be able to decide the level of protection for your soybean seeds; treatment is optional for soybean seeds.
Fungicides, Insecticides or Nematicides?
With the cost of treatment ranging from $10 to $20 per acre, depending on the level of protection, it all comes down to what delivers the best return on investment for your operation. “[If you’re planting in wet conditions,] I would definitely be looking at fungicides. Moisture breeds pathogens,” Glogoza says.
The biggest threats are Phytophthora and Pythium. If the pathogens exist in your field and conditions are wet, there’s a good chance one of those will show up. Phytophthora thrives in soil temperatures above 60°F, and Pythium prefers temperatures below that point.
Consider an insecticide if you’re concerned about wire worms, seed corn maggots, white grubs, cutworms, bean leaf beetles or aphids. Check the treatment label to see what pests it targets and if they are suppressed or controlled. Suppression means there can be some pest mortality, but it’s difficult to predict how much. With control, expect 90% to 95% mortality, Glogoza says.
Another damaging pest, nematodes, might also be damaging enough to consider treatment. If nematodes are present in your fields, they will likely be a problem for several years, so you may want to consider either biological or systemic treatment options. Biologicals use living organisms such as bacteria to protect the roots. Systemic nematicides are taken up and integrated into the root system. When nematodes feed on the root, they die.
Review your fields and what areas had challenges last year. Be sure to get your crop off to the right start while maintaining profitability.
What seed treatments have you considered or used on soybeans? What was your experience? Let us know in the comments.