Effect of nitrogen and phosphorus fertilization on the growth and qualitative attributes of Japanese mint (Mentha arvensis L.)

Abstract

The study investigated the impact of varying nitrogen (N) and phosphorus (P) levels on the growth and development of Japanese mint (Mentha arvensis L.) through key agronomic traits during the rabi season (2022-23) at the Department of Agronomy, Crop Research Centre, Asian International University, Imphal (Manipur). The experimental design consisted of five nitrogen levels (N1 to N5, ranging from 40 kg to 200 kg of N per hectare) and three phosphorus levels (P1 to P3, ranging from 40 kg to 80 kg of P2O5 per hectare). Parameters including plant height, number of branches, stem girth, canopy spread, days to 50% flowering, leaf area and menthol (%) were recorded at 30, 60, and 90 days after planting (DAP). The results showed that nitrogen significantly influenced plant growth, with the highest nitrogen level N4 and N5 generally promoting greater plant height, stem girth, and canopy spread. Phosphorus application, however, did not show a consistent significant effect across all parameters. The interaction between nitrogen and phosphorus did not significantly affect any of the growth parameters. Furthermore, no significant differences were observed in days to 50% flowering and leaf area in response to nutrient treatments. Nitrogen levels have a pronounced effect on the growth performance of Japanese mint, influencing key parameters such as plant height, stem girth, and canopy spread. Phosphorus application, however, did not significantly alter growth patterns.