Premier Co-op
Overcrowding
After nearly a decade in this role, it is not often a question of “if” herds are overcrowding, but more so “how much”? There are a ton of factors to consider whe...
Mar 31, 2026
Tar Spot
Jul 07, 2025
Don't Let Disease Sneak in
Crop and weather conditions are aligning for a potentially strong year, making this a season worth investing in. The majority of corn and soybean fields are showing excellent growth and yield potential. However, the consistently high relative humidity over the past few weeks has created ideal conditions, not only for crop development, but also for disease pressure, particularly tar spot. When tar spot reaches 50% severity on the ear leaf during grain fill, yield losses of 20-60 bu/ac have been reported.-
Caused by the fungus Phyllachora maydis
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Looks like small, raised black circular lesions on stalks, leaves, and husks
(These spots cannot be rubbed off) -
Most frequently appears between silking and late grain fill
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Can overwinter on infected residue left on the soil surface
Favorable Conditions for Tar Spot
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Cool temperatures
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High humidity
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Prolonged leaf wetness
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Irrigated fields are especially susceptible
Confirmed presence in PA, IN, IL, IA, MO, KS, NE, and now WI means this disease is active and spreading. See where tar spot has been reported here: https://corn.ipmpipe.org/tar-spot/
We recommend evaluating your fields now, especially if you’re nearing V10 or have a history of Tar Spot pressure. If you’d like help scouting or building a fungicide plan, our agronomy team is ready. Contact your Premier agronomist today to get started.
