Effects of Nitrogen Fertilization and Soil Water Content on Seed and Oil Yield in Perennial Castor in a Mediterranean Environment

Castor (Ricinus communis L.) is an oilseed species that can be grown as a semi-perennial in Mediterranean environments, including the coastal areas of Sicily. The present study investigated optimization cultivation techniques for castor, with crop being maintained over two-year period, through evaluation different agronomical inputs order to increase seed yield. effects irrigation (I) and nitrogen fertilization (N) on oil yield their components were assessed castor cultivated typical semi-arid environment. Four levels (I0, I30, I60, I100: 0, 30, 60, 100% evapotranspiration—ETm restoration, respectively) main plot three (0, 120 kg N ha−1) sub-plot considered. Irrigation mostly affected number racemes per plant, capsules raceme, weight. content was, average, 39.2% 45.6% first second year, respectively. highest was obtained by I100N120 treatment (4154.0 ha−1); however, combination high soil level (N120) medium water availability (I60) resulted satisfactory yields. reduction intermediate could also environmentally friendly strategy not significantly affecting