Effect of nitrogen and row spacing on growth, yield and economics of niger (Guizotia abyssinica)

A field experiment was conducted during the rainy season of 1998 and 1999 to study the effect of nitrogen and row spacing of niger [Guizotia abyssinica (L.f.) Cass.]. Application of 20 to 40 kg N/ha had significant favourable effect on plant height, branches/plant, capitula/plant, test weight and biological yield. Niger seed yield increased significantly with increase in N level up to 40 kg N/ha, but stalk yield and harvest index showed significant increase only up to 20 kg N/ha. The maximum gross returns of Rs 6,771/ha and net returns of Rs 3,408/ha were obtained with the application of 40 kg N/ha which were 9.37 and 61.56% (gross returns) and 13.52 and 65.49% (net returns) higher over 20 and 0 kg N/ha respectively. However, the maximum benefit: cost ratio(1.01) was realized with 40 kg N/ha. Closer row spacing of 15 cm increased significantly almost all the growth and yield attributes as well as seed yield and N uptake over wider row spacings of 30 and 45 cm. Row spacing of 15 cm gave maximum gross returns (Rs 6,462/ha), net returns (Rs 3,447/ha) and benefit: cost ratio (1.14).