Traditional Culture Encyclopedia - Weather forecast - How do you understand long daylight and short daylight?

How do you understand long daylight and short daylight?

1. From March 22 to September 22, the sun shines directly on the Northern Hemisphere. The days are long and the nights are short in various places in the Northern Hemisphere. The higher the latitude, the longer the sunshine time, which is a long-sun area;

2. From September 24th to March 20th of the following year, the sun shines directly on the southern hemisphere, and the days and nights are short and long in the northern hemisphere. The higher the latitude, the shorter the sunshine time, which is a short-day area.

About long-day plants and short-day plants:

Long-day plants

Long-day plants refer to plants whose sunshine time is longer than a certain value (usually more than 14 hours) Plants that can only bloom, and the longer the light time, the earlier they bloom. Common long-day plants include wheat, barley, rye, oats, rape, beet, spinach, onion, cabbage, celery, carrot, cabbage, rhododendron, etc.; < /p>

Short-day plants

Short-day plants are plants that can bloom only if the day time is shorter than a certain value (usually more than 14 hours of darkness). Short-day plants generally bloom in autumn. Common short-day plants bloom in autumn. Sunshine plants include rice, cotton, soybeans, chrysanthemums, sorghum, American tobacco, cocklebur, late rice, wintersweet, hemp, etc.;

Distribution and characteristics

Plants require a certain length of daylight for flowering , this characteristic is closely related to the length of natural sunshine in the growing season of its place of origin. Short-day plants originate from low latitudes, while long-day plants originate from high latitudes. In areas near the equator, long-day plants generally cannot Flowering and fruiting, only short-day plants are distributed. In high latitudes, there is almost 24 hours of sunshine in summer, and only long-day plants are available.