Effect of Low Temperature Stress on the Hemerocallis Fulva

The suitable temperature is the necessary condition of plant growth and development; the temperature is too high or too low will have harmful effects on plant growth. Low temperature damage to plants is called cold damage, and high temperature damage to plants called heat damage. According to the degree of low temperature and the damage condition of plants, cold injury and chilling injury are divided. The adaptability and resistance of plants to low temperature are called cold hardiness of plants. The plant's adaptability to high temperature and its resistance to heat are called thermal resistance of plants. The winter blight of the lily has influenced its application and popularization in the garden. The cold resistance of 31 lily varieties was studied, which provided reference for landscape designers. The observation shape was observed in winter, and the measured results of water content, bound water content and relative conductivity of the leaves were compared. There were great differences in the winter viewing period of 31 varieties, of which 7 varieties were evergreen in winter, but there were also differences in cold hardiness. Among the 7 evergreen varieties, 4 are excellent, suitable for viewing in winter, and can be widely used in gardens.