It is important to protect soybeans from various pathogens, even at the seed level. Wade Webster, NDSU Extension Plant Pathologist, has some vital information.
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It is important to protect soybeans from various pathogens, even at the seed level. Wade Webster, NDSU Extension Plant Pathologist, has some vital information.
What is In the Pod: Soybean Updates?
The NDSU Extension weekly podcast In the Pod: Soybean Updates delivers timely insights and expert advice on soybean production.
Bruce Sundeen:
You're listening to In The Pod, soybean updates, a weekly trek into the latest soybean information from NDSU Extension. Before planting soybeans, it's important to consider seed treatment. Today, we're talking about protecting soybeans from various pathogens. Let's go through the details with Wade Webster, NDSU Extension plant pathologist. Wade, why are seed treatments important for soybean production?
Wade Webster:
Soybean seed treatments are incredibly important to help make sure those plants can get a good head start in the beginning of the season. So there's a lot of different types of seed treatments. We do have the fungicides. We have insecticides and different inoculants. As far as from a pathology perspective, we're just gonna focus on those fungicides and making sure that we are fighting off some of those pathogens that we may be seeing within that soil so we can protect them, get a good final plant populations, give them the best chance that they can of having optimal yields that season.
Bruce Sundeen:
Wade, in the early season, what are the most common seedborne and soilborne pathogens that soybean growers need to know about?
Wade Webster:
Yeah. So of those soybean seedling diseases or those pathogens that we're dealing with, we do have four of them. They're kinda broken up into two separate groups. The first two are Phytophthora and Pythium or what we call water molds, and those need a lot of moisture in that soil. And because of that moisture, they have little spores that can swim throughout that soil and they can move little distances at least from where they are originating from going after those soybean roots. And then we have two others called fusarium and rhizoctonia. Those are what we call our true fungi. And those pathogens typically need wet soil conditions, but they don't need standing water like they do with the water molds. Now these pathogens, they typically only affect early within that season, within that first two to three weeks again when the seed treatments are effective, but Phytophthora is the only one that can cause disease throughout that entire season, throughout all growth stages of soybean production. For all of these, seed treatments are incredibly important, but they are not the only management strategy that we have to deploy to combat these.
Bruce Sundeen:
What about environmental conditions? How does that affect the need for seed treatments? And at what point does it become essential?
Wade Webster:
There's a lot of different considerations when thinking about seed treatments. Now some of these can include a history of seedling diseases or poor emergence within your individual fields. You may have low spots within your field that just naturally accumulate more moisture, especially after heavy rainfall events. And so those are gonna be areas that we're gonna need to pay attention to and look out and specifically apply these seed treatments in those areas. There's different environmental conditions. Again, I mentioned moisture with those water molds, but we need to also pay attention to temperature too. Most of these need very high temperatures, so above 70 degrees of soil temperature, but the Pythiums especially are what we consider an early season pathogen because it needs those cool soil conditions. Typically, that will be those early planted fields, 50 degrees or around that 50 degree mark for temperature of that soil. Just because they have differing levels of temperature, there's still some cases in which these Pythiums can have higher temperatures and still be able to cause infection.
Bruce Sundeen:
Wade, what are some important factors when choosing a seed treatment, and how can farmers tell if they're effective?
Wade Webster:
Yep. So within using the proper seed treatment so I did mention that there are water molds and there are true fungi. Now these seed treatment products, they're not going to target each one individually. So we need to make sure that we are applying the correct active ingredients for those different pathogens that we have in our field. So the water molds have very specific active ingredients that are not going to impact the growth of the fungi, again, Rhizoctonia and Fusarium, and inversely, the other way around too, in which the products that are targeting these pathogens such as fusarium and rhizoc are not going to impact the water mold species. If you know you have problems with all groups of these seedling pathogens, then we need to make sure we have a full fledged seed treatment on our beans so that we have full protection throughout that early emergence stage.
Bruce Sundeen:
Thanks, Wade. Our guest has been Wade Webster, NDSU Extension plant pathologist. You're listening to In the Pod, soybean updates, a weekly trek into the latest soybean information from NDSU Extension.