OVERCOMING ANTAGONISTIC EFFECTS OF NA-BENTAZON ON SETHOXYDIM ABSORPTION

The influence of adjuvants, inorganic salts, and herbicide formulation s on the antagonistic effect of Na-bentazon on sethoxydim absorption w as studied in quackgrass. Adjuvant BCH 815 00, at 2.4 L ha-1 alone or at 1.2 L ha-1 combined with 1.1 kg ha-1 of ammonium sulfate, added to the sethoxydim and Na-bentazon spray mixture overcame the antagonism o n C-14-sethoxydim absorption in quackgrass. Crop oil concentrate at ra tes up to 9.6 L ha-1 did not overcome the antagonism. Adding ammonium phosphate or ammonium nitrate to the spray solution was as effective a s adding ammonium sulfate in overcoming the antagonism caused by reduc ed absorption of sethoxydim even from the combination of Na-bentazon p lus Na-acifluorfen. Ammonium salts and NH4-bentazon overcame the antag onism of Na-bentazon by forming readily absorbed NH4-sethoxydim.