Maize is native to Central and South America, there is no specific time of introduction to China, the history of cultivation in China is about 470 years. According to archaeological discoveries, as early as 10,000 years ago, there was wild corn here, and the Indians planted corn for 3,500 years.

Archaeologists have found remains of a corn culture in the Tehuacan Valley in Puebla state between 7,000 B.C. and A.D. 1540, showing how Paleo-Indians gradually began to harvest wild fruits and transitioned to cultivating corn in captivity while hunting activities became increasingly rare.

Extended information

Maize ecological characteristics: maize is a temperature-loving crop, the whole life cycle requires higher temperatures. Corn biological effective temperature of 10 ℃. Seed germination requirements 6-10 ℃, below 10 ℃ germination slow, 16-21 ℃ germination flourish, germination optimal temperature of 28-35 ℃, 40 ℃ or more to stop germination. Seedlings can tolerate short-term -2 - 3 ℃ depending on the temperature.

Erupting period requires 15-27 ℃, flowering period requires 25-26 ℃, grouting period requires 20-24 ℃. Different corn varieties of temperature requirements are different, China's early maturity varieties require cumulative temperature 2000-2200 ℃.

Middle-maturing varieties 2300-2600 ℃; late-maturing products and 2500-2800 (3000) ℃. Most of the world's corn-producing areas are concentrated in July isotherms of 21-27 ℃, frost-free period of 120-180 days.

Baidu Encyclopedia - Bracts

Baidu Encyclopedia - Corn