As crops continue to mature, there are still pests to scout and management decisions to be made.
One pest to keep in mind this time of year is soybean aphid. Soybean aphids have been around for a couple weeks in South Dakota, so its important to stay on top of scouting. There are two effective methods of scouting traditional scouting and speed scouting. Both approved methods are effective; however, speed scouting is designed to take less time. For details on how to perform each method, visit extension.sdstate.edu and search aphid scouting.
Keep in mind, if you determine management of soybean aphids is necessary, pyrethroid-resistant aphid populations have been documented in many counties in South Dakota. SDSU Extension entomologists do not advise using this class of insecticides in South Dakota for soybean aphid management. However, should you spray pyrethroid insecticide for control of aphids, closely monitor the population to ensure effectiveness.
If you experience a pyrethroid failure, contact Adam Varenhorst at [email protected].
For a more timely and comprehensive look at pests currently facing crops in the state, subscribe to the SDSU Extension Pest & Crops Newsletter.
Grain storage
In other news, we have reached small-grain harvest for many growers. As harvest continues, good quality grain storage practices sometimes get pushed aside.
In most situations, its not necessary to treat grain with a protectant insecticide before binning as long as its removed from storage by May or June of the following spring or fed to livestock within a year of harvest. However, if you plan to store longer than this, you should only apply a protectant after the grain reaches optimal storage moisture.
There are seven main steps to stored grain integrated pest management to consider:
- Structural and maintenance components: Keep bins clean and repaired. Keep a 10-foot perimeter around your bins free of vegetation and be sure to clean up grain spills outside of the bin. Before filling the bin check for any leaks that might allow precipitation or rodents in. Clean bins well, ridding them of as much old grain as reasonably possible (never put new grain on top of old grain).
- Residual insecticide sprays: Residual insecticides can help protect grains, but be sure to follow all labeled instructions. Spray inside walls, ledges, floors, and sills. Spray outside walls and base.
- Condition grain: Store clean, dry grain. For long-term storage corn should be at or below 13-14% moisture, soybeans at 11%, wheat at 13.5%, and oil sunflowers at 8% or less.
- Proper aeration: Run bin fans during cool, dry periods to ensure uniform temperatures and reduce moisture.
- Use insecticide protectants: Treat grain as it is moved into storage.
- Regularly inspect grain: Stored grain should be inspected often; at least once per week until it reaches 55F or below, at which time inspections every two weeks should suffice. When inspecting grain, dont forget to follow safety procedures and always have another person outside the bin with a cellphone, wear a properly attached harness, and always break up crusted grain using a long pole or other tool from a distance.
- Treat infestations when necessary: If there is an insect infestation, move grain and re-treat; cold weather can help kill insects when moving grain. Other options include feeding the infested grain, fumigating the bin, or selling at a reduced price.
For more details on preventing stored grain pests and insecticide application, go here.
Upcoming events
For sign-up and details, visit extension.sdstate.edu/events.
- Forage Field Day July 31, 9 a.m. to 3 p.m. at Castana, Iowa
- Garden Hour Aug. 5, Aug. 12, Aug. 19, and Aug. 26, 7 p.m. online webinar.
- Whole Farm Planning Integrating health care and health insurance Aug. 13, 5:30-8 p.m. at Watertown.
- Cottonwood Field Station Field Day Aug. 15, 9 a.m-noon MDT 19 miles east of Wall.
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