Since the 1990s, and particularly within the past decade, soybean seed treatments have become a common tool for farmers from all regions. Some farmers use them as insurance against poor germination rates. Others like the protection against seedling diseases when planting in cold, wet soils. Recently, farmers have started adding nematicide treatments to help fend off nematodes and biological treatments for growth promotion.
Given the sheer number of options available, navigating the seed treatment world can be disorienting for farmers. With that in mind, we invited Iowa State researcher Alison Robertson, Ph.D., to discuss the categories and uses for seed treatments. Robertson specializes in the study of soybean pathogens and seedling diseases.
Q: How should a farmer select a seed treatment?
A: Seed treatments may contain active ingredients such as fungicides, insecticides or nematicides to control pathogens and pests, and biological products for growth promotion. The first thing we look for is whether a seed treatment is designed for one specific purpose or if it offers a range of benefits. Typically, a farmer should use a seed treatment with three or four active ingredients, because of the diverse set of pathogens in the soil.
Q: What are the primary reasons farmers should use seed treatments?
A: Most soybean pathologists recommend a seed treatment if you are planting into cold, wet soils. Also, if there’s a history of poor stand establishment, if you are planting lower populations or planting into poor seedbed conditions. Depending on your individual farm circumstances, it might not be necessary to use seed treatments on all your acres.
Q: What should farmers who use seed treatments look for after planting?
A: Some treatments can slightly damage the plants, so after emergence a farmer should scout his fields and see if there is any burning on the cotyledons. This isn’t a sign that anything is wrong, but it does provide evidence that the treatment has worked. After a couple of days, the plants grow out of the damage, and research indicates that yield is not affected.
Q: Are there new or recent developments with seed treatment technology?
A: There has been quite a lot of work looking at biologicals, not as stand-alone treatments, but in partnership with treatments that address pathogens in the field. In addition, nematicides have been developed recently to help fight off soybean nematodes.
Q: Other than seed companies, where should farmers go for more information on seed treatments?
A: First, your local land-grand universities, extension offices and extension newsletters are excellent sources of regional information. Also, the Plant Management Network’s Focus on Soybean is an excellent place to find information about seedling diseases.