胡麻是我国华北、西北主要的油料作物,历年播种面积在八、九百万亩。据多年试验证明:胡麻种子有适应低温发芽能力,一般在1—3℃时,便可萌动发芽。在一对真叶期间,若气温短时降到零下2—4℃,都不受冻害。甚至降到零下5—6℃,也仅有轻微冻害。因此,胡麻对我国北方的倒春寒、春霜具有较强的抗御力。1980年5月14—16日,河北张家口坝上地区发生倒春寒,气温骤 Flax is North China and Northwest China’s major oil crops, sown area over the years in the eight, nine million mu. It has been proved for many years that flax seeds can adapt to germination at low temperature, usually germinating at 1-3 ℃. During a pair of true leaves, if the temperature drops to minus 2-4 ℃ for a short time, it will not be frost damage. Even down to minus 5-6 ℃, only a slight frost damage. Therefore, flax on northern China’s late spring, spring cream has a strong resistance. May 14, 1980 May 16, Zhangjiakou, Hebei dam area upside down, the temperature suddenly