Onion

Onion (lat. Allium cepa L. var. cepa) is a vital vegetable crop belonging to the Amaryllidaceae family. It is a biennial plant grown primarily as an annual for its bulb, which develops from the thickened leaf bases known as scales, serving as storage for carbohydrates and water.

Originally native to the regions of Central and Southwest Asia, the onion has become one of the most widely cultivated vegetables globally. Its versatility allows it to adapt to various climatic zones, making it a cornerstone of both small-scale gardening and large-scale industrial agriculture.

The botanical structure of the onion includes a fibrous root system and hollow, cylindrical leaves. The development of the bulb is triggered by the length of the day (photoperiod) and temperature, which are critical factors that determine the yield and quality of the bulbs at the end of the season.

Successful onion cultivation requires well-drained, fertile soil with a neutral pH. Proper moisture management is essential: the crop needs consistent hydration during the vegetative growth phase but requires dry conditions during maturation to ensure the proper skin drying and longevity of the bulbs.

To ensure high productivity, farmers must monitor and manage several common threats:

• Downy mildew (Peronospora destructor)
• Neck rot (Botrytis spp.)
• Fusarium basal rot
• Onion fly (Delia antiqua)
• Onion thrips
• Stem and bulb nematodes