EFFECT OF GRADED LEVELS OF NITROGEN ON PRODUCTION OF FLOWER, OIL AND BULB OF TUBEROSE (Polianthes tuberosa L.)

A field experiment was conducted to determine the effect of different levels of nitrogen on flowering, essential oil and bulb production in tuberose (Polianthes tuberosa L. cv Rajat Rekha). Four treatments of graded level of nitrogen as (N0=0, N1=120, N2= 220 and N3=320 kg/ha-1) were evaluated under hot subtropical climatic conditions on loamy soils. Application of graded level of nitrogen significantly increased the number of leaves / clump (20.47%), plant height (37.35%), leaf area (32.86%), spike length (35.25%), number of florets / spike (43.23%) and flower yield / clump (93.03%) in N3 as compared to control, N1 and N2,respectively. Nitrogen application @ 220 kg ha-1 reduced days to flowering (by 13.36%), increased vase life (by 17.57 %), enhanced essential oil (by 0.128 %) and increased total bulb yield (by 66.94%, 34.01%) and 3.97% over control, N2 and N3, respectively.