Field studies were conducted at Alexandria and St. Joseph, Louisiana to evaluate the compatibility of Staple in tank mixtures for controlling johnsongrass. Staple at 1 oz ai/A was used in combination with Assure II at 0.068 lb ai/A, Bugle at 0.098 lb ai/A, Fusilade 2000 at 0.188 lb ai/A, Poast Plus at 0.28 lb ai/A, Select at 0.125 lb ai/A, Roundup D-Pak at 1.0 lb ai/A, DSMA at 2.27 lb ai/A, and MSMA at 1.0 lb ai/A. A surfactant at 0.25% v/v was added to treatments.

At Alexandria, tank mix antagonism occurred when controlling johnsongrass after mixing Staple with either Poast Plus, Fusilade 2000, or Select. However, a synergistic effect was noted when mixing Staple with MSMA. No tank mix effects were observed when mixing Staple with Bugle, Assure II, or DSMA. Rainfall was 0.42 inches 1 week before treatment (WBT) and 2.02 inches 1 week after treatment (WAT).

At St. Joseph, a decrease in johnsongrass control occurred when Staple was mixed with each of the grass herbicides. However, a synergistic response did occur when Staple was mixed with Roundup. A total of only 0.16 inches of rain was recorded at this location from 1 WBT to 1 WAT.