What is the relationship between the severity of frost and topography and management conditions? How to prevent freezing injury?

Topographically, the frost on the north slope hit by the north wind is serious, while the frost on the south slope is light. It is heavier under the mountain (early germination and flowering) and lighter on the mountain (late germination and flowering); Low-lying land is heavier and flat land is lighter.

Judging from the management conditions, the thriving trees are slightly frozen and seriously weak.

Measures to prevent frost:

① Choose plots with light frost for farming.

(2) Strengthen fertilizer and water management, make trees strong, irrigate in early spring, delay germination and relieve frost.

③ Control pests and diseases, prevent early defoliation and enhance tree vigor.

(4) Before and after flowering, according to the weather forecast, the whole garden should be irrigated the day before frost or sprayed with water 1-2 hours before frost, and the temperature of the microclimate in the garden can be increased through the condensation of water.

⑤ Before first frost, the temperature was increased by smoking. The ignition time should preferably start around first frost time and last until the sun comes out.