مشخصات پژوهش

Sweet corn is susceptible to weed competition for nutrients, moisture, and light interception. Herbicides labeled for use on sweet corn are limited. Hence, it is necessary to provide information about the POST sulfonylurea herbicides and mixtures and their different degrees of sensitivity in sweet corn varieties. The objectives of this experiment were to evaluate the efficacy of sulfonylureas and nicosulfuron+bromoxynil/MCPA and mesotrione/s-metolachlor/terbuthylazine as post herbicide mixtures on broadleaves and grasses weed species, sweet corn grain yield and crop injury. Field experiments were conducted in 2017-19 to investigate the efficacy of the acetolactate synthase (ALS)-inhibiting herbicides nicosulfuron at 80 g a.i. (active ingredient) ha-1, nicosulfuron/rimsulfuron (37.5+37.5)% at 131.25 g a.i. ha-1, foramsulfuron at 45 g a.i. ha-1, and mixture of herbicides nicosulfuron at 80 g a.i. ha-1+bromoxynil/MCPA (20+20)% at 600 g a.i. ha-1, mesotrione/s-metolachlor/terbuthylazine (3.75+37.5+12.5)% at 1343.75 g a.i. ha-1 on the grain yield of three sweet corn varieties. The results indicated that nicosulfuron, nicosulfuron+bromoxynil/ MCPA and nicosulfuron/rimsulfuron, respectively, controlled≥ 90% of Amaranthus retroflexus L. and Solanum nigrum L. at Mashhad. A reduction in biomass nearly ≥ 80% was observed in A. retroflexus, Cyperus rotundus L., Heliotropium europaeum L., Echinochloa crus-galli (L.) Beauv., Abutilon theophrasti Medik. by these herbicides in Sari, Iran. The applications of nicosulfuron, foramsulfuron and mesotrione/s-metolachlor/terbuthylazine at 80, 45 and 1343.75 g a.i. ha-1 respectively, to ‘Golden KSC403su’, mesotrione/s-metolacholor/terbuthlazine at 1343.75 g a.i. ha-1 to ‘Merit’ and nicosulfuron and mesotrione/s-metolachlor/terbuthylazine at 80 and 1343.75 g a.i. ha-1 respectively, to ‘Chase’ were associated with the maximum sweet corn yield. The experiment showed that weed control improved grain yield on sweet corn varieties through sulfon