Basil (Ocimum basilicum L.) is an aromatic plant of economic importance in Brazil, very used as a spice for food preparation. It is also used to obtain essential oil, which important in the perfume industry. The purpose of this experiment was to analyze the effect of five irrigation water depths, as well as an economic viability analysis of the application of irrigation in basil production. The experiment was carried out from March to October 2007. The water depths were based in the cumulative class A pan evaporation (CPE): 0, 50, 75, 100 and 150% CPE. The analyzed variables were dry weight for leaves and flowers, content of essential oil, and dry mass and length of root zone. The essential oil yield and net return were calculated. The third harvest was possible only under irrigation. The daily excessive water depth was detrimental to plant development. The 100% CPE water depth showed the maximum dry mass productivity (4,248.67 kg ha-1), as well as the maximum essential oil yield (58.26 kg ha-1) with net annual profit of R$ 2,543.82 ha-1.
irrigation scheduling; medicinal plants; class A pan evaporation; aromatic plants
