Midsummer Management Decisions
Rescue Herbicide Applications in Soybeans
The last few years has seen the industry as a whole struggle with post emergence herbicide applications in soybeans. It should always be the goal to get full control with one multi-mode of action post emergence application. Sometimes that doesn’t happen. If a rescue treatment is your only option check the herbicide label for information on these points that need to be considered.
Know the Rotational Crop Restrictions – Herbicide products that contain the active ingredient fomesafen (Flexstar®, Top Gun®, Battlestar®, Warrant Ultra® to name a few) have a 10 month restriction before planting corn. This window should be even longer if the weather turns abnormally dry. We suggest stopping fomesafen application by July 1 and switching to another active ingredient.
Know the stage of the soybeans– Many herbicide and spray adjuvant products can damage the delicate flowers on a soybean plant. Before spraying make sure to check your field’s stage and speak with your chemical provider about crop safety concerns.
Know the preharvest interval – Herbicide, fungicide, and insecticide preharvest intervals can have huge variability. While we generally don’t run into any issues with this until later into August, it never hurts to check the label for this information early.
Timing is crucial when it comes to getting big returns on fungicide applications. Ask yourself the questions below to determine if any of your fields could be designated ‘high risk’. Begin scouting those fields the last week of June for disease pressure and crop stage. Apply fungicide immediately following full tassel. This will bring early disease control and maximum return from the other plant health benefits such as slowed respiration rates and nitrogen efficiency. Talk with Jacobsen Seed Representative for more information.
What’s this hybrid’s sensitivity to disease? Genetics play a large role in how a hybrid will respond to disease. Talk with all of your seed representatives about each hybrid in your operation and their disease susceptibility.
What is my field’s history of disease? Certain crop pathogens can over winter in crop residue. Fields that have had a history of disease, are corn on corn or have a lot of residue in general should be scouted more often.
What does the weather look like? – Warm rainy/humid weather can help kickstart foliar diseases in corn. Areas with persistent fog or heavy dew are also favorable to disease development. Hot nights are stressful to corn and the plant health benefits from fungicide can be very beneficial during warm weather patterns.