A field experiment was conducted to investigate the performance of soybean (c.v. Americana) when established with zero tillage technique on Imperata dominated area. Four different techniques of alang-alang control i.e. imazapyr (2.0 kg a.i./ha), glyphosate (2.5 kg a.i./ha), glufosinate (3.0 kg a.i./ha) and manual cultivation were arranged factorially with time of plantings i.e. 1, 2 and 3 months after treatments.
The alang-alang damages varied with herbicides and times. Imazapyr (2.0 kg a.i./ha) showed slow appearance of damage at 3 months after application, which was only 69%, while that of glufosinate was already down to 48% due to regrowth.
No phytotoxicity was recorded, but the yield was low.