We found and confirmed some Southern Rust of corn this week in Tattnall County. However, the incidence in the field was extremely low, and I have only seen it in one field so far. Any growers with later planted corn that has not reached dent with good yield potential may want to consider spraying a fungicide to protect their crop. We recommend to protect corn from rust until late dough/dent stage, however, some people will use fungicides to protect it until black layer.
Corn will generally reach dent stage somewhere around 100 days old. We are seeing some corn that has reached dent before that time however, since it has been so warm and accumulated more heat units than normal. Corn still needs water at dent stage, though. Corn can still use up to .3o inches per day at this stage. That’s still over 2 inches per week! We will be watching the corn now for black layer, which is when we can stop irrigating corn. You can see the milk line in kernels below. As the milk line goes further down the kernel, it will be approaching black layer stage.