Gangadharappa, P. M.Hiremath, J. S.Chavan, Mukesh L.Ragunatha Reddy., R. LKoulagi, SumangalaMAHANTESH, P. S2018-07-062018-07-062016-07UHSBhttp://krishikosh.egranth.ac.in/handle/1/5810057793TH563An investigation was carried out to study the effect of row spacing and nitrogen levels on growth, yield and quality of Japanese mint (Mentha arvensis L.) in the Department of Plantation, Spices, Medicinal and Aromatic Crops, K. R. C. College of Horticulture, Arabhavi during 2015-16. At harvest (100 DAP), maximum plant height, stem girth, plant spread, branches, leaves per plant, total dry matter production, essential oil content, menthol content, fresh herbage yield per plant, nitrogen content in plant and available nitrogen in soil after harvest was noticed at row spacing 60 cm. Whereas, the highest fresh herbage yield per plot, fresh herbage yield per hectare (23.95 t), oil yield per hectare (176.22 kg) and nitrogen uptake was noticed at row spacing of 30 cm. At 90 DAP, carotenoid, leaf area, specific leaf weight and harvesting index were maximum at 60 cm. At harvest, maximum stem girth, plant spread, number of branches, leaves per plant, total dry matter production, harvesting index, fresh herbage yield per hectare (21.18 t), essential oil content, oil yield per hectare (169.46 kg), menthol content, nitrogen content in plant and nitrogen uptake was maximum in plants supplied with 150 Kg N/ha. At 90 DAP, carotenoid, leaf area, leaf area index and specific leaf weight were maximum at 150 kg N/ha. There was no significant interaction effect on growth, physiological and yield parameters. Highest net returns and B:C ratio was observed in plants spaced at 30 cm row spacing and supplied with 150 kg nitrogen per hectare.ennullThesis