Cucumber was first brought back to the Central Plains by Zhang Qian's mission to the western regions in the Western Han Dynasty. It is widely cultivated in all parts of China, and it is cultivated in greenhouses or plastic greenhouses in many areas; It is widely planted in temperate and tropical regions.
The planting time of immature cucumber mainly depends on the temperature index requirements, followed by sunlight: when the minimum night temperature is higher than 10 ℃, the daytime temperature is 20 ~ 30 ℃, and the soil temperature at 0 ~ 10 cm is higher than 12 ℃, direct seeding can be used. In autumn, cucumber can be planted in the open field by direct seeding. In the middle and lower reaches of the Yangtze River, it is usually sown in the first and middle of March in spring. The natural conditions of this crop of cucumber are good, and the varieties with vigorous growth, strong fruiting ability, large melon sticks and high yield can be selected for cultivation. The sowing time of summer stubble is from late May to mid June. In the middle and lower reaches of the Yellow River, seeds are sown from mid April to early may in spring, and from late June to early August in autumn. The greenhouse is OK all year round.
Delicious cucumber cucumber knowledge expansion 1. Cucumbers like warm, but not cold. The suitable temperature for growth is 10 ~ 32 ℃. It grows best at 25-32 ℃ in daytime and 15-18 ℃ at night; The optimum ground temperature is 20-25 ℃, and the lowest is about 15 ℃. The most suitable temperature difference between day and night is 10-15 ℃. The photosynthesis of cucumber was poor at 35 ℃, the obstacle of high temperature appeared at 45 ℃, and the cucumber was frozen to death at - 2 ~ 0 ℃. If the cucumber was tempered at low temperature, it could bear the low temperature of 3 ℃.
2. South China varieties are more sensitive to short sunshine, while North China varieties are not strict with the length of sunshine. They have become sunshine neutral plants. Their light saturation point is 55000 lux and light compensation point is 1500 lux. Most varieties grow well under 8-11 hours of short sunshine.
3. Cucumber has high yield and water requirement. The suitable soil moisture is 60-90%. The soil moisture should not be too much at seedling stage. The soil moisture is 60-70%. Sufficient water must be supplied at fruiting stage. The soil moisture is 80-90%. The suitable air relative humidity of cucumber is 60-90%. If the air relative humidity is too high, it is easy to get disease and reduce yield.
4. Cucumber likes wet but not waterlogging, likes fertilizer but not fertilizer, so it is better to choose fertile soil rich in organic matter. Generally, the soil with pH between 5.5 and 7.2 is preferred, but the pH value of 6.5 is the best.