Main measures for anti-freezing of citrus fruit trees

In order to prevent sudden low temperature and cold wave, try to reduce the degree of freezing damage of citrus. Winter citrus antifreeze can do the following measures.

1. Choose a suitable microclimate environment for the construction of the park: the saplings on the hilly slopes should be selected from the south slopes of the sheltered sun; the flat gardens should have windbreaks in the east, north and west of the orange orchards. The wind-proof forest can be used for evergreen trees such as camphor and privet.

2. Selection of citrus varieties with strong cold resistance: Citrus genus, citrus subgenus evergreen fruit tree, with many varieties, and the difference in cold resistance between varieties is also great. Among the citrus varieties that have been planted locally, the cold resistance is from strong to weak: Wenzhou mandarin, Nanfeng tangerine, ponkan, navel orange, orange (hybrid orange and orange), pomelo. Navel oranges, oranges and pomelo cannot be developed in large areas when planting selected varieties.

3. Timely application of base fertilizer: The time of citrus application of base fertilizer should be completed locally from late October to mid-November. Too early to promote the late autumn bud, consumption of nutrients to reduce the cold resistance of the tree, too late due to low temperature is not conducive to root wound healing.

4. Irrigation in the garden: Entering the middle and late November, the citrus begins to be filled with water, and the soil in the garden should be kept moist in the absence of rain in winter. According to the weather forecast, refill the water once every 3-5 days before the cold wave.

5. The main pole of the plant is coated with white soil: the main pole is painted with 30-40% lime liquid, and the grounding plant and the rootstock are grafted to the soil. The soil pile is more than 30 cm high. Applying white soil can reduce the degree of damage caused by melting snow and the occurrence of post-freezing crack disease.

6. Suppressing steaming heat preservation agent: Spray the whole canopy once every 5-7 days before the cold air comes with 200 times of steaming and heat preservation agent. Repeat the spray immediately after the cold wave.

7. Crown cover: When the minimum temperature drops below zero, the canopy is covered with a non-woven fabric or plastic film. When the cold wave turns fine, the cover can be uncovered when the temperature is above 5 degrees Celsius, and the frost is covered at night. In the case of permitting conditions, simple plastic greenhouse insulation can be built before the end of November.

8. Clear the snow in the canopy: When encountering heavy snow, shake the canopy branches in time to shake off the snow on the canopy to prevent the snow from breaking the branches.

9. Ground lime: When the night is clear after snow, the acres in the orange garden are sprinkled with 50-100 kg of granular lime. Quicklime can increase the temperature in the garden by decomposing the emitted gas and reduce the harm of radiation cooling.

10. Foliar spray fertilizer: After the cold wave, choose sunny at noon (between 10 am and 3 pm) to spray water once every 1-2 days, for 5-6 times. Spray 0.3% urea and 0.2% potassium dihydrogen phosphate solution once every 7 days or so for 3-4 times. Reduce the citrus to restore the tree potential due to dehydrated leaves and foliar fertilizer after freezing.