In order to study the phenology and competition of potato and safflower, as compared to those of the pure cropping, a study was carried out using factorial experiment with completely randomized block design, with three replications. This study was done in experiment field of University of Mohaghegh Ardabili in 2010. The investigated treatments included potato pure cropping in the fixed density of 6 plants pre m 2, safflower pure cropping with the densities of 6, 12 and 18 plants per m 2 and the intercropping of potato (6 plants pre m 2 density) with safflower in the densities of 6, 12 and 18 plants per m 2. The analysis of variance in phenology stages of pure culture and mixed with potatoes showed that all treatments were significant differences. Comparison mean the stages of phenology of safflower intercropping with potatoes showed that two stage emergence and stem elongation earlier seen in plant grown intercropping 18 plant in per. Mixed safflower plants and potatoes compared to other treatments. Delay was seen the phenology stages of flowering and handle the product because the longer vegetative phase and later getting into the reproductive stage, in terms of lime. Safflower competition mean the stage phenology of safflower effected density of potato showed that pure cultures of safflower compared with intercropping earlier spend of emergence, the stem elongation and head visible, flowering and seed ripening. Coefficient of relative congestion in all treatments on potatoes is greater than one, this study shows advantage competitive potatoes compared to safflower. Similarly, the smaller of these indexes suggest weak competition in safflower as compared to potatoes. Amount of relative yield total of potatoes and safflower in all treatments intercropping was smaller than the one. It shows that both components mixed to compete for use limited recourses.
