Sensitivity of Barley (Hordeum vulgare) to Herbicides of Different Modes of Action

Field studies were carried out during the winter seasons of 2006–07 and 2007–08 to evaluate herbicides of different modes of action for selective weed control in barley at the Agronomy Research Farm of CCS Haryana Agricultural University, Hisar. Clodinafop (40 to 70 g/ha) and fenoxaprop (90 to 150 g/ha) inflicted 20 to 53% and 28 to 40% crop injury, respectively two weeks after application (WAT); however, plants recovered later on and no crop injury was observed 8 WAT. Pinoxaden (40 to 60 g/ha) was safe to crop and only 7% injury was observed at the highest application rate, 2 WAT which disappeared later on. Similarly, carfentrazone caused leaf injury within three days which was reduced to 7% 2 WAT and disappeared quickly. No injury was observed for metsulfuron (4 g/ha) or 2,4-D ester (250 and 500 g/ha). Isoproturon and 2,4-D ester 1.0 kg/ha and tribenuron 30 g/ha suppressed the crop initially, but it was not significant and crop recovered. UPH 906 at 45 and 50 g/ha wrecked 70 to 83% injury, respectively to barley crop 2 WAT and there was no recovery 8 WAT. CIL-H at 60 and 70 g/ha caused 45 to 57% crop injury 2 WAT which reduced to 17 and 37% 8 WAT. Atlantis (mesosulfuron+iodosulfuron) 10.8 to 21.6 g/ha resulted in 50 to 65% injury 2 WAT; injury reduced to 36% 8 WAT, but not at higher rate (67%). Similarly, Total (sulfosulfuron+metsulfuron) at 32 g/ha inflicted 65 and 45% injury 2 and 8 WAT, respectively. AE F 130060 alone at 8.12 g and in combination with MKH 6561 (5+22 and 7+28 g/ha) inflicted heavy damage to crop resulting in 48, 73 and 80% injury, respectively 2 WAT and 47, 97 and 100% mortality 8 WAT. Pinoxaden was found to be most advantageous grass weed killer for barley without any crop damage; clodinafop and fenoxaprop injury, though disappeared after four weeks may not be desirable due to their inconsistent results against Phalaris minor in wheat under rice-wheat growing zones. Isoproturon and fenoxaprop can be used in barley as early post-emergence against grass weeds if there is no resistance to these herbicides in P. minor, whereas pinoxaden can be used against both Avena ludoviciana and P. minor. Metsulfuron and carfentrazone can effectively be used for the control of broad leaf weeds in barley and as tank mix with grass herbicides for broad spectrum weed control.