Abstract: Four doses of 32% formamidosulfuron·methyliodosulfuron sodium saline dispersion granules 14.4, 22.8, 31.2, 45.6 g（a.i）/hm² were set, 30% formamidosulfuron aqueous dispersion granules 30 g（a.i）/hm² were used as control agents, and manual weed control and blank control were set. The effect of 32% formamidosulfuron·methyliodosulfuron sodium saline dispersion granule on weed control in the summer maize field and its effect on summer maize yield were studied. The weed’s stems and leaves were sprayed during 2~6 leaves after 22 days in maize sowing. Four kinds of weed populations were monitored on 20, 40 and 60 days after spray treatment, the nutrient accumulation of weeds was analyzed at the same time, and yield was measured after summer maize harvesting. The results showed that the application of 32% formamidosulfuron·methyliodosulfuron sodium saline dispersion granule at 14.4~45.6 g（a.i）/hm² showed good control effects on annual weeds, such as Echinochloa crusgalli, Digitaria sanguinalis, Eclipta prostrata and Portulaca oleracea. After 60 days, the density control effects ranged from 79.82% to 95.35% on Echinochloa crusgalli, Digitaria sanguinalis, Eclipta prostrata and Portulaca oleracea, and the fresh weight control effects ranged from 81.75% to 96.76%, which was similar to that of the control agent of 30% formylcarbamsulfuron aqueous dispersion granule 30 g（a.i）/hm². The effect of each treatment on increasing the yield of summer maize was 20.70%~25.10%, which was significantly better than manual weeding and blank control. In the process of using 32% formylaminosulfuron and methyliodosulfuron sodium saline dispersion granules, no pesticide damage or toxication of human and livestock was found, and it was friendly to the environment.

Key words: formamidosulfuron·methyliodosulfuron, annual weeds, control effects, summer maize, yield