How to Grow Red-Fleshed Kiwifruit: The Latest Cultivation Techniques and Methods Tutorial
Red-fleshed kiwifruit is a fruit that serves as both food and medicine. Every 100 grams of fresh flesh contains 100-420 mg of vitamin C, which is 5-10 times higher than citrus, 11-13 times higher than lemon, and 20-80 times higher than apple. It belongs to the red-fleshed kiwifruit variant of Chinese kiwifruit (Actinidia chinensis) and is a very early-maturing red-fleshed variety. Its offspring have stable genetic traits and strong stress resistance. The fruit is relatively large, with a rich, sweet and delicious flavor, and stores fairly well.
Cuttage Propagation
Propagating red-fleshed kiwifruit by dormant-branch cuttings has the advantages of an abundant source of cuttings, more nutrients stored in the branches, and rapid new shoot growth of the seedlings after rooting, and the plants can leave the nursery in the same year.
1. Selecting cuttings: Thin dormant branches root earlier after cuttings. Thick dormant branches root later and are prone to water loss and flower withering under adverse climatic conditions. However, using branches that are too thin as cuttings makes it difficult to grow sturdy seedlings, so branches with a diameter of 8-10 mm should be selected as cuttings.
2. Timely cutting: Kiwifruit trees are generally pruned from January to mid-February, and the pruned branches can be used as cuttings, inserted as soon as they are cut. If cuttings are collected early but planting is delayed, apply a protective agent to the cut ends, then wrap them in plastic film for storage, or store them at 5°C, or store them in a cool, open-field location. No matter which storage method is used, strict precautions must be taken to prevent the cuttings from losing water and drying out. The cutting period should be no later than April. The cutting bed soil should be clean fine sandy soil or sandy soil.
3. Cutting treatment: To improve the seedling survival rate, after red-fleshed kiwifruit cuttings are trimmed, soak them in a 50-fold dilution of rooting promoter for 20 hours, so that the cuttings fully absorb water and rooting is promoted. When a wooden box is used as the cutting bed, the cuttings can be shorter, about 10 cm. When a field is used as the cutting bed, the cuttings should be longer, about 15-20 cm, and in both cases they should be inserted deeply.
4. Timely potting: After the cuttings root, they can be potted. The potting soil should have good water retention, otherwise the growth of the cuttings will be affected. In the early stage of transplanting, the pot diameter should be 10.5-12 cm, and as the seedlings grow, they should be transplanted into larger pots in a timely manner. After the new shoots of the cuttings elongate, they need to be supported with stakes early.
Artificial Pollination
After artificial pollination, red-fleshed kiwifruit can produce large fruit. Fruit without seeds will all drop. The more seeds a fruit contains, the larger the fruit.
1. Pollen collection: Collect the swollen flower buds of the male flowers before they open. Or collect the flowers after they open but before the anthers dehisce. Then sift the male flowers directly through an iron mesh with 2-3 mm openings. Or cut out the anthers with scissors. Or use an anther collector. Then the anthers can be spread thinly on kraft paper or the like and placed at room temperature of 22-25°C and humidity of 50% for 1 day and night, so that they dehisce. After dehiscence, collect the pollen with a sieve of 80-100 mesh. When storing kiwifruit pollen, first place it in a container such as a tea caddy with a desiccant, then wrap 1 teaspoon of pollen separately in medicine wrapping paper, and store it in a cold storage room, taking it out for use whenever needed.
2. Pollination method: Within 3 days after the male flowers open, carry out artificial pollination with a cotton swab or the like. Within 5 days after the male flowers open, fertilization capacity is still maintained, and artificial pollination is reliable when the petals have not yet turned brown. Lycopodium powder can be used as a pollen extender. The degree of extension is generally 30-50 times the volume of the pollen. To enable the pollen to adhere to more pistils, the pollen and lycopodium powder can be put into a plastic bag and fully shaken and stirred. Kiwifruit pollen that has already been diluted and extended with lycopodium powder must be used on the same day. Cotton swabs or feathers can be used as pollination tools. The pollination work must be done carefully and thoroughly. When the stigma of the female flower is in good condition, artificial pollination can sometimes be carried out even in the rain.
Orchard Site Construction
Kiwifruit is a perennial trailing plant with strong growth vigor, rapid growth, large leaves, and dioecious (separate male and female) plants, entering the fruiting period after 3 years. It has the characteristics of liking light, liking moisture, and liking slightly acidic soil, and fearing strong light, waterlogging, and saline-alkaline soil. Choose loam or sandy loam with convenient transportation, fertile soil, and convenient drainage and irrigation. When cultivated on such soil, the root system is well developed, the aboveground part grows vigorously, the yield is high, and the fruit is large with good color. Next best are gravelly soil and clay soil. However, before planting it is best to remove gravel (stones) and replace the soil, and to improve it by mixing in sand. The soil pH should be between 6.5-7.2, and cultivation is possible on hills, gentle slopes, and flat land. When building an orchard on sloped land, contour strip terraces or fish-scale pits should be built to conserve water and fertilizer. Kiwifruit fears strong wind, especially the dry hot wind of summer, which often breaks branches, causing leaf margins to scorch and leaves to fall, so the orchard site should avoid wind gaps, and windbreak belts should be established in windy areas.
It is best to grow your own nursery stock for orchard establishment, as this ensures quality. If purchasing seedlings, you must pay attention to distinguishing grafted seedlings from seedling (seed-grown) plants. Seedling plants have smaller leaves, more fuzz, darker green leaf color, and prominent leaf tips. Grafted seedlings have large leaves, less fuzz, lighter leaf color, and round or oval leaves with non-prominent leaf tips. In the Guanzhong area, wild delicious kiwifruit (Actinidia deliciosa) should be selected as rootstock, so that the seedlings grow sturdy with strong stress resistance. Jinyan kiwifruit is a dioecious plant, so when establishing an orchard, in addition to planting female plants, a certain number of male plants must also be provided. The male plants are required to have a flowering period consistent with that of the female plants, a long flowering period, a large amount of pollen, strong compatibility, and a high pollen germination rate. Male plants have small, round leaves with deep green color, while female plants have large leaves with slightly lighter color. Male plants have short, thick internodes, while female plants have longer, slightly thinner internodes; male plants have short petioles, while female plants have long petioles. In the buds of male plants, the central main bud has fuzz exposed. In the buds of female plants, the central main bud is prominent, smooth and round, with no fuzz. Kiwifruit buds are plump and exposed, and are easily knocked off during transport, so attention must be paid to protecting them.
Competition in fruit quality is, in fact, competition among varieties. When establishing an orchard, you should consider the arrangement of varieties well and select currently superior varieties and reasonable combinations.
For flat-land cultivation, use 3 m × 4 m. For gentle slopes, use 3 m × 3 m or 3 m × 4 m. For kiwifruit, the T-shaped trellis or improved T-shaped trellis is best, and a pergola trellis can also be used. The hedge trellis has lower yields. When building an orchard on hillside land, plant along the contour lines or dig fish-scale pits for planting. For flat-land orchards, follow the selected row and plant spacing. Dig pits for planting, with north-south rows being preferable. Mark lines and points according to the row and plant spacing, then dig the pits; the planting pits should be 1 m square. Then fill in alternately one layer of grass, one layer of manure, and one layer of soil, with the upper layer of fertilizer best being compound fertilizer or phosphate fertilizer mixed with soil. Note that if there is too much gravel, the soil should be replaced. Generally, apply 50-100 kg of organic fertilizer and 0.5-1 kg of superphosphate per planting pit each year. On the already leveled planting pit, use a shovel to dig a small hole, place the seedling so that it sits at the root crown, straighten the tree, and firm the soil. Too deep or too shallow is not conducive to sprouting. Autumn planting and spring planting are both acceptable, but autumn planting must be covered with soil to protect against cold.
When planting kiwifruit, male plants must be provided in proportion, preferably 8:1. In areas with a lot of rain in May (the flowering period), a ratio of 7:1 can be used. The planted seedlings should have 5 plump buds, and the root system should be properly pruned to help promote new roots. After the water seeps in, cultivate soil up to ground level or slightly above ground level. After sprouting, promptly remove the rootstock suckers. Promptly remove the binding strips at the graft union. To prevent newly emerged branches from being broken by strong wind, be sure to set a bamboo pole beside the sapling and tie the sapling to it. It is best to set up the trellis all at once, or it can be done in stages, as long as it does not affect kiwifruit growth. Promptly carry out inter-row cultivation and weeding, irrigation, and fertilization to promote rapid seedling growth.