Abstarct: Improving the rate of germination and crop growth in early season via increasing crop competitiveness can increase the competitive ability of crops with weeds and reduce weed damage. Thus, in order to evaluate the effect of seed pretreatment and foliage application of salicylic acid on growth and yield of maize (Zea Mayz L.) and weed control, a factorial experiment was conducted as randomized complete block design with three replications in North Khorasan province in 2016. Experimental factors were including weed control at four levels: control (no weeding), weeding all season and application of recommended dose of nicosulfuron (2 l.ha-1) and reduced dose of nicosulfuron (1 l.ha-1) and application of salicylic acid in four levels including; control (no treatment), pre-treatment of seeds with salicylic acid, foliage spraying of salicylic acid and integrated use of salicylic acid (pre-treatment of seed and foliage spraying). Results showed that, plant height, 300 seed weight and protein percentage increased significantly by application of salicylic acid than control. Leaf area index, leaf dry weight, ear diameter, ear length, grain number per ear row, grain yield, biological yield, harvest index, chlorophyll contents were affected significantly by interaction effects of treatments, so that, integrated method of salicylic acid application (foliage spraying and pretreatment of seeds) increased all of the above mention traits significantly in weeding condition. The results revealed that weed density decreased significantly by use of salicylic acid with different methods in weed infest treatment than control. Also, weed density decreased significantly by weeding and use of herbicide in the both concentrations than control, however the effects of recommendation dose on weeds control was less than reduced dose. baxsed on the results of this study, integrated use of pre-treatment of seeds and foliage spraying of salicylic acid could significantly improve the growth characteristics, yield and corn competitive ability with weeds.