Effect of Graded Doses of Nitrogen and VAM on Herbage, Oil yield and Nematode Population on Patchouli (Pogostemon patchouli Pellet)

Experiments were undertaken during 2002–2003 to find out the effect of graded doses of nitrogen and VAM on herbage, oil yield and nematode population on patchouli (Pogostemon patchouli Pellet). Both yield and yield attributing characters i.e. fresh herbage (297.9 g/plant), dry herbage (92.0 g/plant) and oil yield (110.4 kg/ha) were maximum after the application of 150 kg nitrogen and 50 kg VAM/ha. However, essential oil content of the herbage did not vary significantly among the treatments. Highest mycorrhizal colonization of 90.5% and minimum nematode population of 145.0/200 cc of soil was observed in the above treatment. Application of nitrogen @ 150 kg/ha and VAM @ 50 kg/ha enhanced the quantitative and qualitative traits and recorded the highest cost benefit ratio of 1: 3.67.