Basil is popular culinary herb and used as fresh and dried in Iranian and Mediterranean diet. Moreover, basil is used in traditional medicine and well-known flavoring principles. Nowadays consumption of this culinary herb increases due to its flavor and antioxidant activity. Therefor, optimizing biomass production is necessary. One of the agriculture practices that must be optimize for herb production is plant density and light use efficiency. The objective of this study was to evaluate the influence of plant density and cultivar on biomass production. Five different cultivars from different regions of Iran (Ardestan, Marvdasht, Mobarake, Kashan, Babol), with four plant densities, 500, 250, 100, 50 plant m-2 were studied in the experimental greenhouse of horticulture department of Tehran university. The highest yield and light use efficiency obtained in Ardestan cultivar and 500 plants m-2 density. In plants such as basil that yield is depend on vegetative growth, plant density should be taken into account based on cultivar to obtain maximum use of light and obtain better yield.
