Detailed Explanation of Key Techniques for Planting Pomegranate in Courtyards

Pomegranate has green leaves, red flowers and bright-colored fruit, a long flowering period, and fruit that ripens in autumn and can be harvested during the Mid-Autumn Festival and National Day periods. It is a fruit tree valued both for ornamental display and for its fruit. Grown in courtyards, it can beautify the environment and also offers relatively high economic returns. Its cultivation techniques are as follows.

1. Courtyard selection. Pomegranate is a tree species that loves light and fears waterlogging. The courtyard should have sufficient sunlight, relatively high terrain, loose soil and good drainage, and there should be no tall light-blocking objects nearby.

2. Planting techniques. Planting is carried out after leaf fall in late autumn and early winter. For the variety, local red-skin pomegranate may be chosen; its fruit is small but sweet in flavor. Northern large-fruit varieties such as Dahongpao may also be chosen. Pomegranate has a high fruit-setting rate with cross-pollination, so when a relatively large number of plants are to be planted, 2-3 varieties may be selected. Before planting, first dig drainage blind ditches in the courtyard. Then, at a spacing of 4×5 m, dig planting holes 80 cm deep and 80 cm wide; apply 5 kg of organic fertilizer in each hole, mix it evenly with the excavated topsoil and fill it into the bottom of the hole, add a layer of soil, spread the seedling roots in the hole and fill with soil, leaving the root crown of the seedling exposed above the soil surface, gently firm the soil, and water thoroughly once.

3. Fertilizer and water management. Fertilization is mainly based on organic fertilizer. From October to November, dig deep holes and apply livestock and poultry manure, etc.; before flowering, dig shallow holes and apply human urine and feces; during the fruit expansion period, apply a compound fertilizer of nitrogen, phosphorus and potassium once, which is beneficial to fruit growth and flower bud differentiation. After harvesting the fruit, dig shallow holes again and apply human urine and feces, which helps the tree store nutrients. Water shortage during the growing season is unfavorable to growth and fruiting, so water promptly in case of drought during the budbreak period, growing period and fruit expansion period. If there is continuous rainy weather during the growing season, clear the blind ditches and drain promptly to reduce soil moisture.

4. Flower and fruit management. Pomegranate flowers have two flower shapes, bell-shaped and barrel-shaped. Bell-shaped flowers cannot set fruit, while barrel-shaped flowers can set fruit. Pomegranate can bloom in three flushes from May to July. Fruit set from the first flush is the largest, and fruit set from the third flush is the smallest. To ensure that the first-flush flowers set large fruit and set more fruit, the following measures should be taken: 1. Artificial pollination. Along with flower thinning, collect bell-shaped flowers that are about to open, take out the pollen, spread it on glossy paper indoors, turn it frequently so the anthers dry in the shade, and after 30-50 hours when the pollen is shed, separate the pollen from the anther sacs, and store the pollen in a low-temperature, dry, dark place for later use. When the first-flush barrel-shaped flower buds first open, prepare an aqueous solution with 10 g of pollen, 5 kg of water, 0.25 kg of granulated sugar and 5 g of boric acid, and spray-pollinate the parts of the canopy with more barrel-shaped flowers. 2. Application of growth regulators. When the first-flush and second-flush barrel-shaped flowers are in full bloom, spray 40-80 mg/kg gibberellin solution once each time to increase the fruit-setting rate. 3. Flower and fruit thinning. Thin out bell-shaped flowers at the bud stage; when fruit set is already sufficient, all third-flush barrel-shaped flowers should be thinned out except for a few kept for ornamental display.

5. Training and pruning. Use a single-trunk natural open-center form, with a trunk height of about 60 cm and a tree height of about 3 m, 3-5 main branches, main branch angle of about 60°, 2 lateral branches arranged on each main branch, and fruiting branch groups borne on the scaffold branches.

1. Winter pruning. Young trees grow vigorously, so the main focus should be on training scaffold main branches through shaping, with light pruning and long shoots left unpruned, using secondary shoots to achieve early canopy formation and early fruiting. In the full fruiting period, the tree vigor should be stabilized and fruiting branch groups renewed in a timely manner. Pomegranate has strong branching ability and is prone to canopy closure, so vigorous trees should be thinned more and headed back less, while weak trees should be appropriately headed back to stimulate branching.

2. Summer pruning. Pomegranate sprouts branches 2-3 times a year, which affects ventilation and light penetration. During the growing season, remove buds and thin branches so that the tree has good ventilation and light penetration, pinch vigorous branches to cultivate fruiting branches, and remove water sprouts.

6. Disease and pest control

1. Fruit rot. It damages fruit in June, causing the entire fruit to rot, and disease incidence is severe during the rainy season with high temperatures. During the growing season, spray 1:1:160 Bordeaux mixture or 300 times 25% carbendazim solution for control.

2. Cotton aphid. When damage is severe, it affects photosynthesis, causes serious fruit drop and a low fruit-setting rate. At the budbreak stage, spray 3°Be lime sulfur mixture to kill overwintering eggs and newly hatched larvae. If damage is found during the growing season, spray pyrethroid pesticides at 3000 times dilution.

3. Slug moths are the main pests, with 2 generations per year, damaging leaves in summer and autumn and affecting photosynthesis. During winter pruning, pick off the overwintering cocoons of the yellow slug moth and bury them deeply; in summer and autumn, when newly hatched larvae damage leaves, pick off the leaves and concentrate them for destruction, and for young larvae spray 1000 times 90% trichlorfon solution for control.

4. Scale insects. Mainly the crape myrtle felt scale and the tortoise wax scale. When damaging the plant, they suck sap on the branches and trunk, causing tree decline. During the dormant period, manually brush off the scale insects with a stiff-bristled brush. At the budbreak stage, spray 3°Be lime sulfur mixture on the branches and trunk to kill overwintering insect bodies. During the nymph hatching period, spray 1000 times 50% dichlorvos solution or 3000 times decis solution for control.