Lately we’ve seen a few soybean diseases show up within our growing region. It’s important to be able to differentiate between diseases that may show similar symptoms out in the field, such as brown stem rot (BSR), sudden death syndrome (SDS) and charcoal rot. While a disease like frogeye leaf spot may be easily distinguishable, it may be harder to verify what these other diseases are without taking a closer look into the plant.
SDS and BSR are similar looking when they start to show symptoms on the leaves, but when you break the stem of the plant, BSR will have a brown inner pith, compared to a more normal, healthy looking stem on SDS. You may also find blue growths on the roots of an SDS affected plant. Charcoal rot has more of a yellowing leaf symptom than interveinal chlorosis and typically shows up when the plant is stressed from heat and drought. Charcoal rot also creates small dark spores in and around the stem of the plant.
Crop rotation, choosing varieties with tolerance, average-to-later planting dates can all help to minimize issues with these diseases later in the season. Seed treatments will not help with BSR or charcoal rot, but ILEVO can help with SDS susceptible areas.
It is necessary to have a game plan if you have had a history of seeing any of these diseases present on your acres. Thinking ahead with variety selection, crop rotation, as well as other management techniques can help you maximize yield through susceptible fields.
- Jonathan Williams, Southern Region Product Agronomist