Late-Season Soybean Scouting

As we roll into late summer, it’s important to continue to scout soybean fields for signs of disease, insect pests and weed escapes. The notes you take today can have a significant impact on this year’s crop and also help you make more informed decisions in future years. Soybean aphid scouting should be well underway at this point. Aphid pressure has been relatively low throughout most of Latham Country to this point, but it’s important to remain diligent in checking your fields. The generally accepted economic threshold for this pest is an average of 250 aphids per plant with more than 80 percent of plants infested and an increasing aphid population. You’ll need multiple scouting repetitions to determine what is happening with aphid populations in your field.

Two-spotted spider mites are another insect pest in soybeans that have the ability to rapidly increase in population under the hot and dry conditions some of our geography has faced. If mites are positively identified and causing plant damage — and hot, dry conditions are expected to persist — control measures should be considered. Field border treatments may be an option as infestations of spider mites are often confined to field edges.

Late summer is also when several soybean diseases show up, including Sudden Death Syndrome, Frogeye Leaf Spot, White Mold and others. South Dakota State University has a detailed article on late-season soybean diseases.

Knowing which diseases are present in your fields can help determine which variety to plant next year. Planting varieties with disease resistance can be the most effective and the most economical method of disease control. Latham® soybeans have great resistance to the major diseases that occur in our trade territory including: Soybean Cyst Nematode (SCN), Sudden Death Syndrome (SDS), Brown Stem Rot (BSR), Iron Deficiency Chlorosis (IDC), White Mold and Phytophthora.

Soybean pests and diseases can be very serious issues. If you have any questions, feel free to contact me at 402-620-5790 or check in with your dealer.