STM Article Repository

Onion (Allium cepa L.) is member of the family Alliaceae and it is a vegetable that is the most widely cultivated species of the genus Allium. Several factors govern the production as well as the productivity of onion. Level of nitrogen fertilizer is among the factors that govern the production of onion. In this regards, to review the effect of different level of nitrogen on growth and yield of onion was the objective of this review paper. Onions have a variety of medicinal role. Nitrogen is an integral component of many essential plant compounds. Nitrogen is needed to form chlorophyll, proteins and it is a major part of all amino acids and many other molecules essential for plant growth and other critical nitrogenous plant components such as the nucleic acid and chlorophyll. Nitrogen is also essential for carbohydrate use within plants. Results from different climatic regions of the world also show varying responses of onions to applied nitrogen. As increased the level of N, increased the growth trend of the number of leaves, leaf length and plant body that onion has a high nitrogen requirement, particularly in the early stages of growth. Different researcher result indicated that the application of nitrogen fertilizer increased the bulb yield of onion also significantly increased.