Theses & Dissertations Open Access Effect of organic and inorganic nitrogen sources on growth, yield and oil content of sunflower grown in highly weathered soils of Morogoro Mwahija Almasi Irika Sunflower contributes about 40% of total national cooking oil requirement in Tanzania, ranking as one of the most important cooking oil with very high nutritional value. However, its production per unit area ranges between 800 and 1100 kg/… RUF-35636 2015 CC BY 4.0 8 Oct 2015