Influence of Seed Rate and Nitrogen Fertilizer on Yield, Yield Components and Essential Oil of Cumin (Cuminum cyminum L.)

Cumin (Cuminum cyminum L.) is a medicinal plant that is used in food industries, drinks, cosmetics, soap, perfume and cheese. Cumin's drugs are applied in curing disorders of digestive system. Due to its ecological, physiological and economic characteristics, cumin is suitable for cultivation in the dry and semi-dry climates. This experiment has been conducted to determine the best seed rate and amount of N fertilizer on the yield and essential oil content of cumin at the experimental farm of Islamic Azad University of Jiroft, Iran, in 2007. Variable factors were: seed rate (8, 14, 20 and 26 kg/ha) and nitrogen fertilizer (0, 50, 100 and 150 kg of nitrogen per ha.). Traits under study were: number of plants per area unit, number of umbels per plant, number of seeds per umbel, plant height, 1000 seed mass, total dry matter, harvest index (HI), seed yield, and essential oil percentage and rate. Results show that seed rate has a significant effect on number of plants per area unit, number of umbels per plant, number of seeds per umbel, plant height, seed weight and total dry matter, harvest index, seed yield at 1% level and on essential oil percent at 5% level. Also, amount of N fertilizer has significant effect on no. of umbel per plant, no. of seed per umbel, seed weight, and total dry matter, harvest index, and seed yield at 1% level. No. of umbel per plant was decreased by increasing seed rate and increased by increasing N fertilizer. Total dry matter increased by increasing seed rate and N fertilizer, but HI decreased. The highest seed yield was obtained at 150.7 plants per unit area (969.2 kg/ha) and 100 kg/ha N fertilizer (955.6 kg/ha). The highest seed yield (1016 kg/ha) and essential oil yield (3.4% equal to 36.07 kg/ha) obtained at treatment with 14 kg of seed per hectare and 50 kg of nitrogen (150.7 plant/m 2 ) that are recommended under experimental conditions.