Radiation frostbite occurs in perfectly calm weather, without wind and clouds, and in the hours close to sunrise. The layer of cold and heavy air that forms near the earth’s surface tends to flow down the slopes and depressions of the uneven areas of the earth. Therefore, due to their weight, the cold air flow moves to low-lying lands (hollows) and their accumulation in low points causes the hollow lands to act like cold air ponds and they are at high risk of freezing, while Which are safer on the slopes due to the flow of cold air drainage, so these areas are much more exposed to frost than other areas close to them. Obstacles such as walls with tall and dense trees (windbreaks) at the end of the garden slope prevent cold air from leaving the garden and intensify frost.
Ways to reduce radiation frost damage are:
1. Vegetation, fences and buildings should be designed to prevent the transfer of cold air around the plant area, direct cold air out of farms and gardens and thus reduce the risk of cold.
2. Refraining from plowing and clearing trees during the period of flower opening until fruit formation
3. Removal of weeds and accumulation of living or dead plant debris from the soil surface: For inactive protection against frost, it is better to remove all cover crops from orchards. Improves.
4. Watering the garden on nights when there is a possibility of frost. When soils are dry, there is more air space that prevents heat transfer and storage in the soil. Therefore, in dry years, frost protection is improved by wetting dry soils. Deep wetting of the soil (to a great depth of soil) is not necessary because most of the daily heat transfer and storage occurs at depths above 30 cm.
5. Heaters or flames can be used to compensate for the heat lost through radiation. The best time to use heaters is when temperature inversion conditions prevail. If there is a temperature inversion in the garden or farm, direct heat dissipation can heat the soil and plants. The heaters protect the plants in the garden or field from the danger of cold and frost by creating direct radiation by stirring the air in the layer of temperature inversion.
6. Use of wind generating machines