Abstract :
In order to study the effect of sowing date and plant density on some traits of coriander, an experiment was conducted in research field of Islamic Azad University, Birjand branch, Iran in 2010 as a split-plot experiment based on a randomized complete block design with nine treatments and three replications. The main plot was sowing date at three levels of March 30, April 14 and April 29. The sub-plot was plant density at three levels of 20, 40 and 60 plants m-2.The results showed that with the delay in sowing from March 30 to April 29, umbel number per plant, fruit yield per hectare, fruit and biological yield of single plant significantly decreased 76.7, 76.4, 78.2 and 76.8%, respectively. Also, means comparison indicated that the increase in density from 20 to 60 plants/m2 led to the increase in fruit yield per hectare by 87.6%, but umbel number per plant and fruit and biological yield of single plant decreased 13.7, 37.6 and 34.8%, respectively. Also, sowing date and plant density interaction significantly affected fruit yield per hectare, fruit and biological yield of single plant and harvest index. In total, it is recommended to use sowing date of March 30 with the density
