Effect of sowing date and plant density on yield and yield components of fennel (Foeniculum vulgare).

To study the effect of sowing date and plant density on yield and yield components of fennel in research field of Islamic Azad University, Birjand branch, Iran in 2009 as a split-plot experiment based on a randomized complete block design with three replications. The main plot was sowing date at three levels of March 19, April 9 and April 30 and the sub-plot was plant density at three levels of 6.7, 10 and 20 plants/m2. According to the results, the effect of sowing date, plant density and their interaction was significant on umbel number per plant, seed number per umbel, 1000-seed weight and seed yield. Means comparison indicated that the highest umber number per plant, umber number per m 2 , seed number per umbel and seed yield was obtained at the first sowing date and the delay in sowing significantly decreased them, while it increased 1000-seed weight. Also, means comparison indicated that the increase in plant density led to the significant decrease in umbel number per plant and seed number per umbel but it significantly increased umber number per m2, 1000-seed weight and finally, seed yield. In total, according to the results, it is recommended to use sowing date of March 10 with the density of 20 plants/m2 for the cultivation of fennel in Birjand, Iran since it produced 1163.30 kg/ha.