Biomass and essential oil yields of rainfed palmarosa (Cymbopogon martinii.(Roxb.) Wats. var. motia Burk.) supplied with different levels of organic manure and fertilizer nitrogen in semi-arid tropical climate

A field investigation was carried out for 2 years (1994-1996) on a red sand y loam soil in the semi-arid tropical climate of South India, to study the influence of different levels of farm yard manure (FYM) (0 and 15 t/ha per year) and fertilizer nitrogen (0, 40, 80 kg N/ha per year) on the biomass a nd essential oil yields of palmarosa (Cymbopogon martinii (Roxb.) Wats. var . motia Burk., family, Poaceae) grown under rainfed condition. During the p eriod of investigation, palmarosa gave seven harvests in 2 years with 23.6- 37.2 t/ha total (total of seven harvests) biomass yield, and 99.2-159.1 kg/ ha total essential oil yield per hectare. Application of FYM at 15 t/ha per year increased the total biomass yield by 10.7% and total essential oil yi eld by 10.3% over control (no application of FYM). Addition of nitrogen (N) at 80 kg/ha per year enhanced the total biomass yield by 57.6% and total e ssential oil yield by 60.3% in comparison to no N application. The quality of the essential oil with 1.7% (E)-beta -ocimene, 2.5% linalool, 73.1% gera niol, 15.8% geranyl acetate and 2.0% beta -caryophyllene was found to be go od and was readily accepted in the market. (C) 2001 Elsevier Science B.V. A ll rights reserved.