When was the onion introduced to China?
The onion is also known as ball onion, round onion, jade onion, etc. It is a biennial herbaceous plant of the genus Allium in the family Liliaceae. The prostaglandin A it contains can reduce peripheral vascular resistance and blood viscosity, and it can be used to lower blood pressure, refresh the mind, relieve stress, and prevent colds. It can also clear oxygen free radicals in the body, enhance metabolic capacity, resist aging, and prevent osteoporosis, etc. Now let us take a look at when the onion was introduced to China!
When was the onion introduced to China?
The onion originated in Central Asia or West Asia. In ancient Egyptian stone carvings from 1000 BC, there are pictures of harvesting onions, after which it spread to the Mediterranean region. During the Western Han Dynasty, Zhang Qian traveled to the Western Regions and brought back many species from there, and at that time there were already records of onion cultivation in the Western Regions. After the Age of Discovery, it spread from Europe to the world. It was introduced to North America in the 16th century, reached Japan in the 17th century, and in the 18th century Lingnan Zaji records that the onion was introduced by white Europeans to Macao, China and cultivated in the Guangdong area.
Where are the onion's production areas distributed?
The onion is widely cultivated throughout the world, and there are now many different varieties that have been used in foods around the world. The main onion production areas in China are distributed in Jinxiang, Yutai, Shanxian, and Pingdu in Shandong; Fengxian in Jiangsu; Jiuquan and Wuwei in Gansu; Yuanmou and Dongchuan in Yunnan; Xichang in Sichuan; and Hengchun, Fenggang, and Checheng in Taiwan, China, among other places.
What growing conditions does the onion need?
1. Temperature: The onion has strong adaptability to temperature. Seeds and bulbs can germinate slowly at 3-5°C. The suitable temperature for seedling growth is 12-20°C, for leaves 18-20°C, and for bulbs 20-26°C. Vigorous seedlings can withstand low temperatures of -6 to -7°C.
2. Light: The onion is a long-day crop. During the bulb expansion stage and the bolting and flowering stage, it needs long-day conditions of more than 14 hours. Under high-temperature and short-day conditions, it only grows leaves and cannot form bulbs. The suitable light intensity for onions is 20,000-40,000 lux.
3. Water: Onions should be supplied with sufficient water during the germination stage, the peak seedling growth stage, and the bulb expansion stage, but water must be controlled during the seedling stage and before overwintering to prevent excessive seedling growth and frost damage. The leaves are drought-tolerant and suitable for 60-70% humidity.
4. Soil: The onion has strong adaptability to soil, and neutral loam that is fertile, loose, and well aerated is suitable. Sandy loam easily achieves high yields, but clay loam produces firm bulbs with good color and good storage quality. The root system has weak fertilizer uptake capacity, and high yields require sufficient nutrient conditions.