Main anti-freezing measures of citrus fruit trees

In order to prevent sudden low temperature, cold wave, as far as possible to reduce the degree of citrus freeze damage, winter citrus antifreeze can do a good job of the following measures.

1. The suitable microclimate environment should be selected for garden construction: the south slope area with wind and sun should be selected for citrus planting in hilly slope land, and windbreak belts should be built in the east, north and west of citrus garden in flat land. Windbreak forest available camphor, privet and other evergreen tree species.

2. Citrus varieties with strong cold resistance were selected: Citrus belongs to Yunxiang family-Citrus subgenus evergreen fruit trees, which have many varieties and great differences in cold resistance among varieties. The cold-resistance of citrus cultivars planted in this region is from strong to weak: Satsuma mandarin, Nanfeng mandarin, Ponkan, Navel orange, Zangkan (hybrid of mandarin and orange), Pomelo. Navel orange, hybrid orange and pomelo cannot be developed in large areas locally when planting and selecting varieties.

3. Timely application of base fertilizer: citrus base fertilizer application time should be completed in late October to mid-November. Early should promote late autumn germination, consumption of nutrients to reduce the cold resistance of trees, too late because of low ground temperature is not conducive to root wound healing.

4. Irrigation in the garden: In the middle and late November, the citrus garden begins to irrigate, and the soil in the garden should be kept moist in the case of no rain in winter. According to weather forecast, irrigate enough water 3-5 days before cold wave.

5. White cultivation of main stem of plant: white cultivation of main stem with 30-40% lime solution, soil cultivation at the interface between ground plant and rootstock, mound height of more than 30 cm. White soil coating can reduce the damage of snowmelt and the occurrence of post-freezing split skin disease.

6. Spray steam inhibiting heat preservation agent: spray the whole tree crown with 200 times steam inhibiting heat preservation agent 5-7 days before cold air comes. Repeat the spray once immediately after the cold wave.

7. Crown cover: When the minimum temperature drops below zero, cover the crown with non-woven fabrics and plastic films. When the cold wave turns clear, the cover can be removed when the temperature is above 5 degrees Celsius during the day, and the frost protection can be covered again at night. If conditions permit, simple plastic greenhouse can be built before late November for heat preservation.

8. Clear the crown snow: in case of heavy snow, shake the branches of the crown in time, shake the snow on the crown, and avoid the snow pressing off the branches.

9. Sprinkle quicklime on the ground: 50-100 kg of granular quicklime is sprinkled on the mu of orange garden when it is sunny at night after snow. Quicklime can increase the temperature in the garden by decomposing and emitting gas, and reduce the harm of radiation cooling.

10. Foliar fertilizer spraying: After the cold wave, choose sunny noon (between 10 a.m. and 3 p.m.) and spray clean water once every 1-2 days for 5-6 consecutive times. Spray 0.3% urea +0.2% potassium dihydrogen phosphate solution once every 7 days for 3-4 consecutive times. Alleviate citrus defoliation due to dehydration after freezing and restore tree vigor by foliar fertilizer supplementation.