Changes in Essential Oil Content and Yield of Basil in Response to Different Levels of Nitrogen and Plant Density

Background: Basil (Ocimum basilicum L.) is a valuable medicinal and aromatic plant which is cultivated throughout the world. Therefore, it is necessary to determine effect of important agronomical factors on quality and quantity of its volatile oil. Objective: To determine plant density and nitrogen fertilization effects on quality and quantity yield of basil. Method: This study was done in Research farm of ACECR, Institute of Medicinal Plants & Natural Products Research in 2006 on the base of factorial experiment in randomized complete block design with four replications. All possible combinations of three plant densities (266666, 200000 and 160000 plants ha-1) and three nitrogen rates (0, 50 or 100 kg ha-1) were established. Results: The results indicated that plant density had significant effect (p < 0.01) on yield of dry herbage and oil. Plant density had no significant effect on oil content but due to the increment in dry herbage yield per unit area, oil yield had been significantly increased in higher plant density. Nitrogen fertilization had significant effect (p < 0.01) on all studied parameters. Although, nitrogen application had adverse effect on oil content, nitrogen fertilization up to 100 kg ha-1 increased yield of dry herbage and essential oil. Such increase in essential oil yield was caused by N fertilization due to an increase in dry herbage yield. Conclusion: The maximum yield of dry herbage and oil were obtained in plant density of 266666 plants ha-1 with nitrogen application of 100kgha-1 and was the best treatment in respect of dry matter and oil yield