Once the plants have tasseled, pollen shed begins shortly there after and has already begun in some fields. The photo below shows the silk of an ear that is ready for pollination. Pollen shed only occurs for a limited amount of time and pollination begins from the bottom of the ear to the top. Each silk must capture pollen to fertilize the kernel it is attached to or the kernel will abort. Once the kernel has been pollinated, the silk can easily separate from it.
Now is an important time to be scouting for disease. Northern Corn Leaf Blight (NCLB) and Southern Rust are the two main ones to be on the lookout for. NCLB was found in the Pee Dee this week, but Southern Rust, which is carried by the wind up from the South each year, has not yet been found in SC. We need to be scouting regularly for these diseases. The photo below shows NCLB lesions found in Dillon County this week.
Southern Rust is pictured below. Again, this hasn’t been found in SC yet, but stay on the lookout. This is a bad one and we don’t want it to get away from us.
With corn prices being so low this year, Clemson corn specialist David Gunter is recommending we shoot for just one fungicide application in order to minimize production costs. If possible, it would be best to delay applying a fungicide until Southern Rust has moved into the state; however, if you find NCLB in high concentrations in a field, you may not be able to delay treatment. Timing of fungicide applications should be made on a field by field basis for the time being, though once Southern Rust moves in, everyone will need to make a protective application. The chart below shows some data from David Gunter’s corn fungicide trials from 2014.
Take note of the fungicides used above as well as their timing. The treatments at VT worked well as opposed to the treatments at V6. For more information on fungicides labeled for corn, check out pages 158-160 of the UGA Pest Management Handbook.
Check back for updates on Southern Rust.