Sesame (Sesamum indicum L.) is grown mainly in the tropics. It is typically grown by smallholders with nearly all of its production in developing countries. It is an important source of high-quality oil and protein. Inappropriate use of fertilizers and monocropping are among the major production constraints. The objective of this paper is therefore to review the effect of N fertilizers on sesame growth and productivity. Growth and yield of sesame are greatly influenced by the application of N fertilizer. In most of the sesame-producing countries, optimum seed yield of sesame was obtained from application of 46–100 kg·N/ha. Adequate nitrogen fertilization also improves uptakes of other nutrients, particularly P and K and some micronutrients. Preemergence application of mobile nitrogen (urea) is less efficient due to losses. Mobile form of N fertilizer became available within two days for the crop. Split N applications where the N fertilizer is applied at different growth stages of the crop increases productivity. Side-dress application is one of the easiest ways to maximize nitrogen use efficiency. N fertilizers should be placed 3–5 cm deeper than the seeds and 5–10 cm apart from the plant for side dress but not far than 20 cm. Under optimal environmental conditions, nitrogen fertilizer has no effect on phonological traits but on the growth parameters. In the potential areas, application of 46–100 kg·N/ha gives maximum yield and lowering the application of N to less than 46 kg·N/ha in marginal areas is economical.

Cabbage aphid is attacks plants in the family Brassicaceae (Cruciferae), which includes such important crops such as oilseed rape, Brassica napus L., mustard, Sinapis (Brassica) alba (L.) and nigra (L.) and cabbage vegetables. Field experiments were conducted at Alamata Agricultural Research Center (AARC) during 2019 cropping season to evaluate and verification of insecticide on Cabbage aphid insects, and the corresponding yield of cabbage. The treatments (three insecticide treatments, including unsprayed plots as a control) were laid out in factorial arrangement in RCBD with three replications. The efficacy of Candidate and standard check were recorded 68.12% and 65.21%, respectively. Insecticide treatments significantly reduced the infestation of the insects. The lowest insect population and incidence values of 81.27% and 66.05% and 8.33% and 3.33% were recorded, when treated with lmida-win and ConFidence respectively. Candidate (lmida-win) and standard check (Con-Fidence) reduced cabbage aphid population by 94.6% and 91.2%, as compared to unsprayed plot. In conclusion, the results of the present studies revealed that lmida-win foliar spray was effective in reducing cabbage aphid infestation and increased yield. However, more extensive studies are recommended for developing better management of cabbage aphid through integration of insecticide spray schedules and cultivars to enhance sustainable cabbage production in Ethiopia.