The lowest temperature for grape growth is about 12℃- 15℃, the lowest ground temperature is about 10℃- 13℃, the optimum temperature for flowering is about 20℃, and the optimum temperature for fruit expansion is 20℃-30℃. If the temperature difference between day and night is large, the coloring and sugar content are better.
After the grapes germinate in spring. If the temperature rises quickly, it will easily lead to too many branches, which is characterized by insufficient node length and poor fertilization at flowering stage. In case of late spring cold, more phosphate fertilizer and high carbon organic matter should be applied, and nitrogen fertilizer should be reduced as much as possible.
Although grapes can be planted in various soils, loam and fine sand loam are the best. Although sandy soil has good air permeability, its ability of retaining fertilizer and water is poor. Loam is between sandy soil and clay.
Its water and fertilizer conservation ability is strong, and most of them are very fertile. When the grapes grow vigorously, they are easy to blossom and bear fruit, and the high temperature and light conditions are good.