Essay on replanting of property greening in autumn

(1) comes from the essay "Winter wheat is sown and germinated in autumn, and blooms and bears fruit in early summer of the following year. For this kind of plants, the low temperature in late autumn and early winter becomes a necessary condition for flowering; Under the condition of long sunshine, American tobacco can't bloom when the plant height is 3-5 m in summer, but it can bloom when the plant height is less than 1m when it grows in greenhouse in winter. " It can be known that the external conditions that affect flowering are mainly temperature and sunshine time.

(2) Farmers in northern China have long known that if winter wheat is replanted in spring, it will only grow seedlings and will not blossom and bear fruit. The reason is that the temperature in spring is higher than that in winter, and the sunshine time in summer is long, which is not conducive to wheat flowering and fruiting.

The solution to this problem is to treat winter wheat at low temperature for a period of time before sowing.

So the answer is:

(1) What is the temperature (acquired temperature)? The length of illumination time (or illuminance)

(2) Winter wheat was treated with low temperature for a period of time before sowing, and did not experience low temperature in late autumn and early winter.