Originally published April 20, 2012
The accompanying photograph is of Command injury to drilled Cheniere. The farmer applied the herbicide himself using a well calibrated ground rig. He was able to associate the injury pattern with the first pass of each of two loads he applied that day. We discussed the situation with Henry Stefanski, the FMC representative in an effort to understand why it happened. The problem likely occurred in the process of loading the spray rig. Command 3ME is heavier than water. If the agitator was not running when the herbicide was added to the tank even though there was water in the tank the herbicide settled to the bottom of the tank where a larger dose was drawn into the sump and boom before it could be mixed thoroughly. Thus the first pass of spray contained a higher than desired dose of herbicide resulting in the injury. It also means the remainder of the area sprayed probably has less than the intended amount applied to it.
Even though there is considerable bleaching, long term consequences are not expected to be severe. We recommended that he keep the field moist, but not establish a flood until the new leaves are coming out green. It also means no other herbicides can be applied until recovery is observed. In this case the direct effects may not be as great as the indirect especially if broadleaf weed pressure becomes heavy before recovery is evident.
The LSU AgCenter and the LSU College of Agriculture