The correct method of spraying herbicides is an important factor affecting weed control. In this regard, three types of herbicide sprayers including tractor mounted boom sprayer, knapsack atomizer and knapsack boom micronair were investigated to control weeds in the corn fields of Safiabad Agricultural Research Center, in Dezful, Iran. In order to compare the performance of these three sprayers, a randomized complete block design with five treatments and three replications was implemented. The treatments of this experiment included spraying by a mounted tractor boom sprayer, knapsack atomizer, knapsack boom micronair, and weeding by a human (first control), as well as no weeding and spraying (second control). After identifying the types of weeds in the field, nicosulfuron herbicide was applied. The results showed that the lowest means of weeds dry weight including Cleome viscosa, Corchorus olitorius, Cyperus rotundus, Physalis alkekengi and Convolvulus arvensis belonged to the micronair sprayer treatment with the values of 2.53, 2.92, 2.94, 1.43 and 1.92 g.m-2 respectively. The study of corn yield and yield components showed that among the spraying treatments, the highest mean of biological yield, number of corn plants per unit area, corn ear weight per unit area, number of seeds in a row of an ear, wood weight of an ear, thousand-seed weight, corn plant height, a corn ear weight and seed weight of an ear of corn belonged to micronair sprayer treatment with the values of 30 t.ha-1, 74000 plants per hectare, 12.93 t.ha-1, 36.3 seeds per row, 46 g, 415 g, 299 cm, 260 g and 216 g respectively.