Here are some timely updates for growers as we try to continue and finish up planting for the 2024 growing season.
Southern Corn Rust was confirmed in Decatur County a couple of days ago, but there is no need for us to panic. Southern corn rust (SCR) is a potentially devastating disease in southeastern corn. The good thing for us is that it does not overwinter in our area. Each year the spores from SCR must move from the south northward to infect our crop. You can track the movement of SCR by using this link. Each year UGA Ag and Natural Resource Agents monitor sentinel corn and soybean plots checking for rust diseases. The current SCR map is below. We will continue to monitor the movement of SCR and can assist growers in determining when a fungicide application is appropriate.
As we near pinhead square on much of our cotton crop it is time to begin scouting for Tarnished Plant Bugs and their damage. Tarnished Plant Bugs (TPB) are true bugs similar to stink bugs, they can feed on larger bolls but they do most of their damage to developing squares in the early season. Square retention counts should be made once the cotton reaches pinhead square and continue into week two of bloom. Later in the season it is best to monitor with a drop cloth or sweep net.
To make a square retention count gently pull the top two main stem leaves apart and look for the presence or absence of a small square. When plants are retaining less than 80% of small squares and plant bugs are observed we would recommend the application of an insecticide. Plants with 80 percent first position square retention at first bloom still have maximum yield potential.
Retention of these squares also helps reduce vegetative growth in the plant since energy is being sent to the developing bolls. For threshold levels throughout the season and management recommendations contact your County Agent.
The other rust disease, soybean rust, was also detected in Georgia this week. Soybean rust was detected on kudzu in Telfair County this week and then in Tift County so we need to be aware. Soybean rust can infect plants at any growth stage, but it is most severe after plants begin to flower and set pods. Growers can usually get by with one fungicide application at the R2 stage. This is also when we would recommend boron and Dimilin for control and suppression of foliar feeding caterpillars. With early detection and delays in planting we need to scout fields to make sure that infection is not occurring sooner than R2.
