Tight Crop Input Dollars Will Increase Need to Carefully Manage Foliar Fungicide
By Nora Schultz, Sales Agronomist, CCA
“To spray or not to spray?” This is one of the most common questions throughout the Corn Belt in mid-summer. Crop prices will make it more important than ever to actively manage each foliar fungicide application to get the biggest bang for your buck. Begin scouting high risk fields (see reverse side) starting the last week in June to understand disease pressure and crop stage because timing is critical to large returns with fungicide. Therefore, apply fungicide to corn immediately after tassels have emerged. This will minimize any risk to developing silks as well as maximize protection and plant health during this extremely important stage in the plants life. In soybeans, apply fungicide at the end of R2 (full bloom) to R3 (beginning pods on the top 4 nodes). Knowing the disease pressure in a field is important because the fungicides used today give us the best control when applied before serious infection. Fungicides are often separated into ‘preventative’ and ‘curative’ groups (or a combination of both). ‘Curative’ fungicides are most effective 24-72 hours after infection and do not cure lesions on a leaf.
What is High Risk?
It is important to determine where your areas of highest risk are and give them adequate attention. Below are some characteristics to consider when looking for your high risk areas.
Susceptibility Level of the Hybrid/Variety – Each hybrid/variety will have a different level of susceptibility to certain foliar diseases based on its genetics. Talk with your seed advisers about each hybrid/variety in your operation and make note of ones with weaker scores.
Field History – Many foliar pathogens winter over in crop residue. Understand how much residue is present along with known history of foliar disease. Corn planted into corn residue that had a foliar disease last year increases risk for this season.
Weather – Foliar disease development is often most favorable in rainy/humid conditions. Fields should be scouted more often if this weather or prolonged periods of dew persist. Often hot and dry conditions suppress disease development.
Talk with you Jacobsen Seed Representative about which fields should be your focus and for help scouting.