INFLUENCE OF NITROGEN AND PHOSPHORUS FERTILIZATION ON GROWTH PERFORMANCE AND SEED YIELD OF NIGER (Guizotia abyssinica (L.f) Cass)

Abstract

Niger (Guizotia abyssinica) is an annual dicotyledonous oil crop and the only species cultivated in different countries throughout tropical and temperate zones. This study presents growth performance, seed yield and yield related traits of Guizotia abyssinica variety Kuyyu in different Nitrogen:Phosphorus fertilization rates of 0:0, 10.25:23, 20.5:23, 41:23 kg/ha and seeding rates of 7.5, 10 and 12.5 kg/ha in Gudane sirba Kebele of Guduru district, Horo Guduru Zone, Oromia regional state from June to November 2016 under rain-fed cultivation. The experiment was laid out in RCBD with three replications. Parameters such as plant height, number of branches/plant, number of capitula/plant, 1000 seeds weight (1000 SW), seed yield/ha, total biomass and oil content were measured at harvest. Except oil content which did not go in par with the rest of parameters measured, results showed that plant height, number of branches/plant, number of capitula/plant, 1000 SW, seed yeild/ha and total biomass increased with increasing level of N fertilization and decreased with increasing seeding rate. In all cases, the best performance was observed when plants were fertilized with 41 kg of N/ha with seeding rate of 7.5 kg/ha and this values recommended for farmers to adopt.