INTERACTIVE EFFECT OF SODIUM ABSORPTION RATIO (SAR), BORON RICH IRRIGATION WATER AND NITROGEN APPLICATIONS ON MORPHOMETRIC PARAMETERS OF PALMAROSA [CYMBOPOGON MARTINII VAR. MOTIA (ROXV) WATS.]

A field experiment was conducted at Research Farm of Agricultural College, Bichpuri (Agra), to assess the effect of SAR and boron rich irrigation water with nitrogen and their interaction on morphometric parameters of Palmarosa (Cymbopogon martinii var. motia (Roxv) Wats.). The treatment consists of three types of saline-sodic water having EC8 SAR 12.5 (S1), EC8 SAR 25 (S2) and EC 8 SAR 37.5 (S3). Four levels of boron i.e. B1 to B4 as 0, 2.5, 5.0 and 10 mg kg-1 were used for irrigation of the plants. The three doses of nitrogen as 40 (N1), 80 (N2), and 120 (N3) kg ha-1 were tested through soil application. The plant height and number of tillers per plant were significantly reduced by SAR and boron levels in saline-sodic water but these increased significantly with higher levels of nitrogen (120 kg ha-1). The mean increase in plant height and number of tillers per plant were 2.4 percent and 7.2 per cent. Interaction SAR × boron × nitrogen were found significant in case of herb yield and dry matter production at fourth harvest stage. Each increasing level of SAR and boron decreased the herb yield and dry matter production while useful effect of nitrogen could be observed at each level of SAR and boron. Each higher level of SAR and boron resulted significant reduction in oil content as 11.8 and 15.5 per cent with highest level S3 of SAR37.5 over lowest level S1 of SAR12.5 and B4 level of boron in comparison to B1 level of boron, respectively. The oil production of Palmarosa decreased significantly with each higher level of SAR and boron in saline-sodic water. At fourth harvest, the maximum oil production was recorded with N3 level of nitrogen, which was 19.0 per cent higher in comparison to N1 level of nitrogen. Interactions between SAR x boron x nitrogen were found significant in case of oil content and oil production at various harvest stages of Palmarosa. The increasing levels of SAR and boron generally decreased the geraniol and geranyl acetate of Palmarosa oil at fourth harvest while higher doses of nitrogen slightly improved the same in comparison to lower levels of nitrogen.