Effect of Depth and Method of Irrigation and Nitrogen Application on Herb and Oil Yields of Java Citronella (Cymbopogon winterianus Jowitt.) under Semi-arid Tropical Conditions

A field expenment was conducted during 1992–94 at CIMAP, Field Station, Bangalore, India to study the effect of depth (25, 37.5 and 50 mm) and methods (Ridge and furrow and Broad Bed and furrow method) of irrigation and nitrogen levels (0, 200 and 400 kg N ha⁻¹ year⁻¹) on herb and oil yields of Java citronella. At the highest level of N application (400 kg N ha⁻¹ year⁻¹) ridge and furrow method was better suited for irrigating citronella. However, under lower N levels (0 and 200 kgN ha⁻¹ year⁻¹), as much as 30 % water can be saved by the broad bed and furrow method. The results have shown that highest herb and oil yields of citronella were achieved with the application of 400 kg N and maintaining 25 mm depth of irrigation. Content and quality of oil were not affected either by irrigation or nitrogen.