1.      Introduction: One of the important goals of greenhouse development in Iran is production efficiency and water consumption reduction. Currently, approximately 80% of the country's greenhouses are cultivated with cucumbers, tomatoes, and peppers. Nearly 95% of vegetable crop seeds are imported from other countries. Therefore, one of the high costs of greenhouse crop production is the preparation of seed. The highest price of seed provision is for pepper seed production. Propagation by cutting is a very economical and efficient method for some plants. Environmental conditions such as temperature, light, relative humidity, hormones (especially auxin), carbohydrates, minerals, and other internal substances are effective factors in the rooting of cuttings. Maintaining the relative humidity around the cuttings is very important, especially in the herbaceous cuttings. For better rooting, it should be kept at the optimal level. Excessive temperature causes the growth of buds before root formation and increases the rate of water loss from the leaves. Natural growth regulators, especially auxin in plants, are necessary to produce adventitious roots. Bell pepper is an important vegetable not only because of its economic value but also because of the nutritional value of its fruits, which are an excellent source of natural colors and mineral compounds. The purpose of this research was to investigate bell pepper propagation by using the cutting method to reduce the cost of propagation and production.
 
2.      Materials and Methods: Two types of nodal and non-nodal cutting were taken from 1204 (red color) and 7141 (green color) greenhouse pepper hybrid cultivars. The cutting had at least one leaf and a bud next to the leaf. To prevent rotting, the bottom of the cuttings was treated with Captan fungicide 0.4% for one minute. The cuttings were treated with concentrations of 0, 1000, and 1500 ppm of indole-3-butyric acid hormone for 30 seconds. The cuttings were cultivated in seedling trays in a mixed culture medium of 60% perlite and 40% cocopeat. Seedling trays were placed in a greenhouse with day temperatures of 25-30 °C and night temperatures of 18-23 °C. The Mist system was used to provide the relative humidity for cuttings. Day and night relative humidity was 85-90% and 65-70%, respectively. A factorial experiment was carried out based on a randomized complete block design with three replications. The factors were pepper cultivar, type of cuttings, and indole-3-butyric acid hormone concentration. In order to effect evaluation of different treatments on rooting, one month after planting of cuttings in the seedling trays, the percentage of rooted cuttings, the number of roots, the length of the largest root, and the total length of roots were measured.
 
3.      Results and Discussion: The results showed that the number of roots and the total length of roots in the cutting samples increased significantly in cultivar 7141 (green color) compared to cultivar 1204 (red color). So the number of roots for two cultivars was 7.2 and 6.4, and the total length of roots was 32 and 25.6 cm, respectively. The nodal cutting produced a greater number of roots and the total length of roots than the non-nodal cutting. In nodal cutting, the number of roots and the total length of roots were 7.3 and 31.1 cm. These two traits were recorded for non-nodal cutting at 6 and 25.4 cm, respectively. The presence of nodal roots at the bottom of the cutting increases rooting in pepper cuttings. Better rooting on the nodal can be related to more nutrients and auxin at the nodal site. Both concentrations of 1000 and 1500 ppm of hormone significantly increased the number of roots and total length of roots compared to the treatment without hormone. There was a significant difference in the length of the largest root between the concentration of 1500 ppm and the treatment without hormone. But in this trait significant difference between the concentration of 1000 ppm and the treatment without hormone was not observed. Between the two hormone concentrations, no significant difference was detected in the studied rooting traits. The highest number of roots, 9.5 numbers was observed in nodal cutting with 1000 ppm of IBA.
 
4.      Conclusion: Although pepper is an herbaceous plant, compared to other herbaceous plants such as cucumber and tomato, its cuttings are hard to root. Two weeks after planting in seedling trays, the pepper cutting only formed callus and one or two small roots. In case a large number of adventitious roots are formed in cucumber and tomato cuttings within two weeks. In pepper, it takes about a month for the cutting to produce enough adventitious roots.