How is the Shangdu Onion King cultivated?

The Shangdu Onion King is a new high-yield, high-quality Welsh onion variety bred by agricultural technical experts in Heze City, Shandong Province, through three years of cultivation trials, multi-crossbreeding, and selective and definitive breeding. In 2002, provincial and municipal agricultural experts conducted on-site sampling and yield measurement of a 120-mu demonstration field of Shangdu Onion King in Cao County, which showed: an average of 8,000 kg of fresh onions per mu, with high-yield fields exceeding 10,000 kg, roughly double the yield of ordinary Welsh onion varieties.

This variety belongs to the long-white type, with a single stalk that does not branch, a plant height of 160-170 cm, a white length of 75-85 cm, a straight diameter of 4-5 cm, an average plant weight of 1 kg, and a maximum weight of 1.5 kg. Mature plants have 8-10 green tubular leaves, with sharp leaf tips and a deep green leaf color, covered with a waxy bloom. The white stalk is straight and cylindrical, with no obvious swelling at the base, a crisp and tender texture, few fibers, abundant juice, slightly sweet, and mild pungency, making the commercial onion of excellent quality.

The Shangdu Onion King has strong adaptability, tolerating both low and high temperatures, with an effective growth temperature of 5-35°C, and a suitable plant growth temperature of 15-25°C. The seedlings can overwinter, and they do not go dormant even in hot summers. Moreover, regardless of size, the product can be harvested and marketed at any time, and it can be sown in stages across multiple seasons for year-round supply.