What is the best time to plant winter rapeseed

Winter rapeseed is generally sown in September and harvested at the end of May, but in some areas it is sown in late September. The planting time differs from region to region, and local conditions should always be the standard.

Winter rapeseed distribution areas

1. North China and Guanzhong subregion

Includes the southeastern corner of Gansu, the area north of the Qinling Mountains in Shaanxi, central and southern Shanxi, as well as Henan, Hebei, Shandong and other provinces. It is generally a double-cropping area with two harvests a year. The average annual temperature in the rapeseed production areas is 10°C~15°C, the average temperature in the coldest month is 1°C~3°C, the frost-free period is 180~240 days, and the annual rainfall is 500~800 mm. Rapeseed is mainly winter-type Brassica napus (rapeseed), with a small amount of Brassica rapa (field mustard).

2. Yunnan-Guizhou Plateau subregion

Mainly distributed in Yunnan Province and Guizhou Province. The altitude is above 1000 m, the average temperature in January is above 5°C, winter and spring are dry, and the annual rainfall is about 1000 mm. Winters are warm and dry, with the rainy season from May to October and the dry season from November to April, and evaporation is high. It is a double-cropping area with two harvests a year. Rapeseed includes Brassica rapa (field mustard), Brassica juncea (brown mustard) and Brassica napus (rapeseed) types.

3. Sichuan Basin subregion

Includes Sichuan, Hanzhong in Shaanxi and some nearby areas. The soil in this region is fertile and the climate is warm and humid. The average annual temperature is 10°C~18°C, the average January temperature in most areas is 2°C~5°C, and the annual rainfall is 1000~1200 mm (only 600~800 mm in the Hanzhong area). Sunshine is relatively low. It is generally dominated by one crop followed by a second crop, that is, double cropping. Rapeseed is mainly Brassica napus (rapeseed), with a small amount of Brassica rapa (field mustard).

4. Middle Yangtze River subregion

Mainly includes Hunan, Hubei, Jiangxi and parts of Henan and Anhui. This region has fertile land, a mild climate and abundant rainfall. The average minimum temperature in January is 2°C~6°C, and the annual rainfall can reach 1400~1600 mm. There is often autumn drought, but spring rainfall is more concentrated. Autumn sunshine is relatively strong. It is mainly a triple-cropping area with three harvests a year. It is dominated by Brassica napus (rapeseed), with a small amount of Brassica juncea (brown mustard) and Brassica rapa (field mustard).

5. Lower Yangtze River subregion

Includes Shanghai, Zhejiang, Jiangsu and the eastern part of Anhui Province. This region has a mild climate, with an average annual temperature of 15°C~18°C, an average January temperature of 0°C~4°C, and annual rainfall of more than 1000 mm. Sunshine is abundant. The soil is fertile and water conservancy conditions are good. It is generally a double-cropping area with two harvests a year. It is dominated by Brassica napus (rapeseed); only Anhui and Zhejiang have some Brassica rapa (field mustard), and rapeseed yields per unit area are relatively high.

6. South China coastal subregion

Mainly includes Guangdong Province, Taiwan, China, Fujian Province, Hainan Province, and the area south of Guilin in Guangxi. This region has high temperatures, abundant rainfall and little frost or snow. The average annual temperature is 16°C~17°C, the average January temperature is above 10°C and can reach as high as 21°C, precipitation can reach 1500~2000 mm, and sunshine is abundant. It is generally a triple-cropping or multi-cropping area with three or more harvests a year. Rapeseed consists of early-maturing spring-type varieties with a short growth period. Both Brassica rapa (field mustard) and Brassica napus (rapeseed) are cultivated, but the planting area is very small.