OPTIMISING AGRONOMIC REQUIREMENTS FOR SEED YIELD AND QUALITY OF DILL (ANETHUM GRAVEOLENS L.) OIL

The studies were undertaken on Dill (Anethum graveolens L.) at Punjab Agricultural University, Ludhiana to find out the optimum time of sowing, seed rate, row spacing, nitrogen and phosphorus requirements in order to manipulate its seed yield potential and quality of oil. The research work was carried out during winter seasons of 1982–83 and 1983–84 on a loamy sand soil under irrigated conditions. There were three separate field experiments on dates of sowing (30 September, 15 October, 30 October, 15 November, 30 November and 15 December); seed rates and row spacings (5, 10, 15 kg/ha and 30, 45 60, 75 cm) and nitrogen and phosphorus levels (0, 30, 60, 90, 120 kg N/ha and 0, 20, 40 kg P₂O₅/ha). The results showed that, in order to get the higher seed yield, the crop should be sown in mid of October in lines 30 cm apart and using 10 kg seed per hectare. It should be supplied with 90 kg N/ha. However, the phosphorus application did not help to increase the seed yield. The oil content in seed was maximum in the early sown crop of 30 September/15 October. All other factors like seed rate, row spacing, phosphorus application did not affect the oil content. However, it decreased with the increase in nitrogen levels. The physico-chemical analysis of seed oil showed that its specific gravity, refractive index and optical rotation was not affected appreciably by any of the agronomic factor.