Key Management Techniques for Pomegranate Trees in Late Autumn and Early Winter

 1. Fertilization. After harvesting the fruit in autumn, applying an appropriate amount of human manure and urine helps accumulate nutrients in the tree. The fertilization method is to dig a circular fertilization trench about 30-50 cm deep and about 40 cm wide at the outer edge of the tree canopy, or, centered on the main trunk of the fruit tree, dig radial fertilization holes 30 cm deep and 20 cm wide at intervals around the outer edge of the tree, and dig the trench and apply the fertilizer on the same day. The amount of fertilizer applied should be determined according to tree vigor, tree age, soil fertility, and the current year's yield. In autumn, pay attention to foliar topdressing, which should focus mainly on phosphorus and potassium fertilizers, with a total fertilizer solution concentration not exceeding 0.3%. For topdressing outside the roots, biogas slurry or decomposed manure water can also be sprayed.       

2. Training and pruning. The tree shape of pomegranate is fairly flexible; generally, 4-7 main branches are evenly arranged, with each main branch having 2-3 side branches. Young trees grow vigorously and should be pruned lightly and left to extend, focusing on developing scaffold branches to achieve early canopy formation and early fruiting. During the full fruiting period, branching capacity is strong and the canopy easily becomes crowded; vigorous trees should be thinned more and headed back less, while weak trees should be properly headed back to promote branching.       

3. Deep plowing of the pomegranate orchard. In order to eliminate overwintering pests and diseases in the pomegranate orchard, regardless of the size of the area or the number of pomegranate trees, a thorough deep plowing should be carried out before the beginning of winter. Remove all fallen twigs and leaves under the fruit trees, weeds, and various pruned branches, especially diseased and insect-infested branches, dried branches, dead buds, and mummified fruit, from the orchard, and burn them in a centralized manner or compost them into fertilizer, which can reduce the occurrence of pests and diseases the following year. After cleaning the orchard, deep plow more than 20 cm to destroy the habitat and overwintering environment of pests and diseases and expose overwintering pathogens and pests in the soil to low temperatures so they freeze to death.       

4. Mounding soil for cold protection. After winter pruning and before the soil freezes, mound soil around the root crown of the pomegranate to a thickness of about 20 cm, or build a semicircular mound of soil on the north side of the root crown, 30-50 cm high. The mounded soil should be moist and loose, and soil should be taken from some distance away from the roots to prevent root injury.       

5. Timely winter irrigation. The time for winter irrigation in a pomegranate orchard is generally best when the average soil temperature in the 5 cm soil layer is stable at 5 degrees C. At this time, even if the nighttime temperature drops below 0 degrees C and freezing occurs, it can still thaw after the daytime temperature rises. If winter irrigation is too early, the temperature is still relatively high and evaporation is large, which is not conducive to storing water and preserving soil moisture and reduces the pomegranate's ability to resist cold and prevent freezing. If it is too late, because the temperature is relatively low, the soil becomes compacted, water cannot seep down, and accumulated water freezes, making the root system vulnerable to freeze damage. The amount of irrigation water should be such that on the same day after irrigation all the water infiltrates underground and reaches the root distribution layer, that is, 20-30 cm for immature fruit trees and 70-100 cm for mature fruit trees, with soil moisture maintained at 60%-80% of the field maximum water-holding capacity as suitable. After winter irrigation, loosen the soil in time to preserve moisture and prevent soil compaction.       

6. Pest and disease control.        1. Disease control. The main diseases of pomegranate include dry rot, brown spot, and rough skin disease. In late autumn and early winter, promptly prune off mummified fruit and dried diseased branches on the tree and burn them in a centralized manner to reduce sources of disease.        2. Pest control. The main pests of pomegranate include aphids, peach fruit borers, red spiders, and fruit borers, and integrated control measures can be adopted for the above pests. After harvesting the fruit, remove the old cracked bark from the tree, and use a medicinal paste made of 1:1 clay and 50% phoxim to plug tree holes and smear trunk cracks, so as to minimize the overwintering pest population.