According to the latest USDA crop progress figures released June 22, corn and soybean planting is complete in Michigan. However, there are pockets in the central portion of the state that were inundated with rain a couple of weeks ago, which caused ponding in some fields, says WinField United agronomist Jason Roth. He adds that these could potentially become prevent-plant acres this year.
Michigan does not have a cutoff date for dicamba applications, but already-purchased dicamba products must be used by July 31. Other options include protoporphyrinogen oxidase (PPO) herbicide chemistries (Group 14 herbicides). Applications should include a residual herbicide in the tank. PPO chemistries aren’t going to be as effective as dicamba applied on soybeans post-emergence, and farmers should apply them when weeds are under 4 inches tall.
Tissue tests taken so far this season have indicated nitrogen, sulfur, manganese, zinc and boron deficiencies in Michigan corn plants, so farmers should be diligent about having tissue samples taken in their fields.
Tassel is when most farmers often consider doing a fungicide application, and that growth stage is three or four weeks away in Michigan, says Roth. The state hasn’t seen a lot of disease pressure yet. If this holds, later fungicide applications will probably work better than doing them earlier, says Roth, especially for diseases like tar spot, which can cause significant yield loss late into the grain fill period.
Even in the absence of disease, some hybrids can potentially derive plant health benefits — including optimized respiration rates and water use efficiency — from fungicide applications. If the weather continues to be fairly dry, Roth recommends farmers apply fungicides either early in the day or later in the evening when plant leaves aren’t curled. It’s too early for fungicide applications in soybeans, but it might make sense now for farmers to go out with micronutrients to help optimize soybean nutrition.
Armyworms are currently a problem in parts of Michigan, migrating from wheat fields into cornfields, so farmers should scout to stay ahead of this insect pressure, says Roth.