Detailed Explanation of High-Yield Cultivation Techniques for Korean Zhengjian Goji Berry

1 Variety Characteristics and Traits

The Korean Zhengjian goji berry has large berries, red color, thick flesh, and a soft, moist texture. Its sugar content is 11.3%, which is 3.3%-4.3% higher than that of Ningxia goji berry. It has wide adaptability, tolerates drought, poor soil, and low temperatures, and offers the advantages of early fruiting, high yield, excellent quality, short cycle, and quick returns.

2 Cultivation Techniques

2.1 Fine Soil Preparation. Apply Sufficient Base Fertilizer

The goji berry has wide adaptability and is not strict about soil requirements, but planting in low-lying plots should be avoided as much as possible. Generally, from late February to early March, carry out fine soil preparation and apply 1.125 t/hm2 of organic fertilizer or 0.600-0.675 t/hm2 of special goji berry fertilizer as base fertilizer.

2.2 Planting Method and Density

Use trellis-type close planting cultivation. Generally, erect 1200-1500 cement posts/hm2, and ensure 2 wires between the cement posts to help secure the goji berry branches and vines. Before planting, first cut the goji berry branches into 12 cm segments and plant them around the Awakening of Insects period, with a row spacing of 80 cm, a plant spacing of 35-40 cm, and a planting density of about 53,250 plants/hm2.

2.3 Field Management

2.3.1 Management After Planting and Before Budding After the goji berry branches are cut for cuttings, pay attention to spraying once with lime sulfur mixture, a strong rooting and seedling-strengthening agent, and abamectin before budding after planting, when the branches turn green, to promote rooting and strengthen seedlings and to prevent mites, powdery mildew, black fruit disease, anthracnose, and other diseases.

2.3.2 Tree Shape Training After the seedlings survive, keep one vigorously growing branch as the central trunk. When the plant height reaches 60 cm, pinch off the growing tip to encourage side branches. Within 10-15 cm below the pinching point, evenly select and retain 3-5 side branches in different directions, and remove all other side branches. When the side branches grow to 10-15 cm, pinch them again to encourage the sprouting of secondary branches. At the same time, select one vigorously growing regenerative branch (water sprout) at the top of the main trunk as the central trunk, top it at 25 cm above the canopy, and train the second layer of main branches to bear fruit. In the 2nd year and 3rd year, train the third and fourth layers of fruiting branches according to the above method, generally retaining 5 layers of main branches. Note: retain 3-5 branches in the 1st year, no more than 15 branches in the 2nd year, and no more than 20 branches in the 3rd year. Use soft rope to assist climbing and control excessive growth of branches and seedlings.

2.3.3 Tree Shape Pruning

2.3.3.1 Dormant Period Pruning. (1) Clear the base. Cut off water sprouts sprouting from the base; (2) Cut the top. Cut off upright water sprouts growing within the canopy. However, for canopies that are not tall enough or have gaps, such water sprouts can be used to extend the top to fill the gaps; (3) Clear the interior. Cut off overly dense fruiting branches in the canopy interior and old, weak, diseased, and pest-damaged branches that do not bear fruit or bear few fruits; (4) Trim the periphery. Cut off horizontal branches, thorn-like branches, and overly dense branches, heavily prune old and weak fruiting branch groups for rejuvenation, and retract the canopy if it is too large; (5) Cut the bottom. Remove all branches below 30 cm near the ground.

2.3.3.2 Summer Pruning. (1) In early May, remove or cut off new buds sprouting from the root crown, main trunk, canopy interior, and top, and also cut off dried and dead branches in the canopy; (2) From mid-May to mid-July, promptly cut off useless water sprouts growing from the plant and canopy. In late June, while cutting off water sprouts, top the intermediate branches and strong fruiting branches growing from the middle and upper parts of the canopy to encourage a second layer of branches to bear fruit.

2.3.4 Timely Topdressing In June, apply fruit-setting fertilizer at the appropriate time, applying 150 kg/hm2 of 3-element compound fertilizer (content above 14%), and carry out intertillage and weeding at the same time. After mid-June, carry out foliar fertilization. Every 10-15 d, use 1.50-2.25 kg/hm2 of monopotassium phosphate mixed with 450 kg of water to spray the canopy evenly once, and spray 2-3 times. After the fruit ripens, spray foliar fertilizer once every 7 d, generally 2-3 times, to promote fruit ripening.

2.4 Control of Diseases, Pests, and Bird Damage

2.4.1 Disease and Pest Control The main diseases are powdery mildew, black fruit disease, and anthracnose. The main goji berry pests are aphids and mites. Comprehensive control measures should be adopted. In addition to strengthening fertilizer, water, and field management, chemical control should also be used.

2.4.1.1 Aphids. Reasonable sparse planting helps ventilation and air permeability. Clear residual branches, fallen leaves, and weeds in and around the orchard, and burn them outside the orchard to eliminate insect eggs. In mid-April when aphids begin to hatch, use 150-300 mL/hm2 of 25% deltamethrin emulsifiable concentrate diluted with water plus 300 times dilution of 40% sulfur suspension concentrate and spray once. After an interval of 10 d, spray again with 300 times dilution of 0.6% matrine for control. At the same time, insert yellow plastic boards coated with organic oil in the field to trap and kill winged aphids. In mid-May, at the early stage of aphid occurrence, spray with 225 g/hm2 of 50% pirimicarb wettable powder mixed with 450 kg/hm2 of water, and in early June spray once more with 300 times dilution of 0.6% matrine.

2.4.1.2 Eriophyid mites. According to the living habits of eriophyid mites, especially their overwintering characteristics, in early October or 15 d before bud opening the following year, spray the entire goji berry orchard with 300 times dilution of 40% sulfur suspension concentrate to massively kill adult eriophyid mites that have not yet entered or emerged from overwintering sites. After adult mites emerge from overwintering, spray with 1000-1500 times dilution of 20% amitraz (Manke) emulsifiable concentrate or choose 2000-2500 times dilution of 5% hexythiazox (Nissorun) emulsifiable concentrate. The control measures for rust mites and eriophyid mites are basically the same; control rust mites together with eriophyid mite control.

2.4.1.3 Black fruit disease. When black fruit disease occurs in goji berry, spray with 1500 times dilution of 25% carbendazim emulsifiable concentrate for control.

When carrying out disease and pest control in goji berry, attention should be paid to promoting the use of new, highly efficient, low-toxicity, and low-residue pesticide formulations, such as abamectin, imidacloprid, Hanjian, agricultural streptomycin, monopotassium phosphate, and Aiduoshou. Comprehensive control should be carried out 4-5 times each year.

2.4.2 Bird Damage Control During the fruit ripening period, nets should be set up around the orchard in time to prevent birds from eating the fruit.

3 Fruit Harvesting and Processing

From late July to late October, manually pick 3-5 times. Pick with the fruit stalk attached.