What are the ecological adaptation characteristics of hemp?

Hemp can adapt to a wide range of temperature, especially in the seed germination period and the early stage of seedling growth, so it can also be planted in some alpine regions, and it can also germinate and grow in autumn sowing in Heilongjiang, Jilin, Inner Mongolia, Henan and other provinces. Hemp seeds can germinate at the low temperature of 1 ~ 3℃, but it is suitable for sowing when the soil temperature is stable at 8 ~ 10℃. The optimum temperature for seed germination is 25 ~ 30℃. When the temperature is 8 ~ 10℃, it takes 15 ~ 19 days for germination, and when the temperature is 23 ~ 26℃, it takes 3 ~ 4 days for germination. The suitable temperature for seedling growth is10 ~15℃; The rapid growth period is 18 ~ 30℃, and the optimum temperature is 19 ~ 23℃. The suitable temperature from flowering to seed maturity is 65438 08 ~ 20℃. Seeds can tolerate the low temperature of -5 ~- 12℃ in a short time from germination to early seedling growth. However, in the late growth stage, the flower organs were not tolerant to low temperature, and the flower organs were damaged at-1℃ at flowering stage, and the flower organs died at -2℃, especially the male flowers.

Hemp is a light-loving crop and a short-lived plant. Adequate sunshine is beneficial to axillary bud germination and inflorescence development of plants, which can improve seed yield. Weak light can inhibit axillary bud germination, reduce branches, promote apical growth, and improve fiber yield and quality. Under the condition of short sunshine, hemp blooms and bears fruit in advance, with short plants and low fiber yield. The daily sunshine hours after emergence are controlled at 10h, which can bloom 20 ~ 40d earlier than natural light. Long light can prolong vegetative growth period, thus increasing fiber yield. Therefore, "planting in the south and planting in the north" is widely used in production, that is, introducing hemp seeds from low latitudes to high latitudes for hemp harvesting and cultivation, and the effect of increasing production is very obvious. But the span is too long, the mature seeds can not be harvested, the fiber maturity is poor, and the tension is low.

Hemp is a tall crop, which needs more water and fertilizer. In the growing period, it is more resistant to weather drought than soil drought, which requires a certain amount of precipitation or irrigation water. Deep soil layer, loose and fertile soil, rich organic matter, low groundwater level, convenient irrigation and favorable for growth. The suitable pH value of soil is 6.0 ~ 6.5, and slightly alkaline soil can also be planted. Sandy loam, the hemp skin planted is thin, white in color, soft in fiber, strong in tension and good in quality; When planted in clay loam, the hemp skin is thick and the fiber yield is high, but it contains more glue, the fiber is coarse and hard and the quality is poor; Heavy clay, sandy soil and calcareous soil have adverse effects on growth; It is difficult to protect seedlings in alkaline soil, and it is not suitable for growing hemp.

There are great differences in stress resistance among cannabis varieties. The varieties with strong cold resistance and drought resistance include Yanchi hemp, Huangzhangxian hemp and Fuping hemp, Wuchang hemp and Liaoyang hemp with strong lodging resistance, Laiyang hemp, Wuchang hemp, Lu 'an hemp, Dayao hemp, Huating hemp and Hancheng hemp with strong water and fertilizer resistance, and Wuzhai hemp, Fuping hemp and Huating hemp with strong waterlogging resistance.