Key Management Techniques for High-Quality Red Fuji Apple Trees in the Year of Planting
Key Management Techniques for High-Quality Red Fuji Apple Trees in the Year of Planting
The time for planting apple saplings can be chosen in spring or autumn. In spring, it is generally chosen after the soil thaws and before the fruit trees bud. At this time, the saplings have a long post-planting recovery period and bud later, which can easily cause slow sapling growth. Autumn planting is generally chosen after leaf fall and before the soil freezes. At this time, the ground temperature is relatively high and the soil moisture content is relatively high. After the sapling roots are injured, the wounds heal easily and early, and new roots can grow. Moreover, the saplings bud earlier the following year, which helps improve the survival rate of planted saplings. It should be noted that fruit trees planted in autumn need to have soil mounded over them for cold protection before winter. For orchards with dry, windy spring weather and no irrigation conditions, it is preferable to plant apple saplings in autumn.
2 Trunk heading
Before the saplings bud in spring, the trunk should be headed according to the shaping requirements and sapling quality. Generally, the trunk is headed 80.0-100.0 cm above the second graft union, that is, on the cultivar branch section. Plump buds should be retained below the cut, and the cut diameter should be more than 0.8 cm. If the trunk height is not tall enough or there are no well-growing plump buds within the shaping zone of the trunk, heavy short pruning can also be done at a plump bud. When the sapling grows to the height at which the trunk can be headed, head the trunk in the following spring before the tree buds. If the soil fertility is not particularly rich, heading the sapling trunk can promote strong growth of the main trunk and help form a good tree shape as early as possible. When the soil is relatively fertile and the saplings grow strongly and luxuriantly, not heading the trunk can also be chosen.
3 Plastic film mulching
After the saplings are planted in spring, irrigate once with enough water. After the soil in the tree dries slightly, tidy the tree, do shallow hoeing to loosen the soil, rake and break up soil clods, shape the tree into a shallow dish shape that is higher outside and lower inside, then cover the tree with 1 sq m of plastic film. Make a hole in the center of the plastic film, then slip it down over the sapling trunk from the top so that the plastic film lies on the ground. The center hole in the film and the edges of the film should be pressed firmly with soil. This can significantly increase the surface soil temperature of the tree, prompt the saplings to produce new roots earlier, promote root growth, and improve the survival rate of planted fruit tree saplings. When planting apple saplings in autumn, the four tasks of planting, trunk heading, bagging, and film mulching can be carried out at the same time. However, apple saplings planted in spring should be covered with plastic film immediately after planting.
4 Bagging saplings to retain moisture
After the saplings are planted, put a plastic bag over the branches and trunk to reduce water evaporation from the branches and trunk. When putting on the plastic bag, cover all the aboveground part of the branches and trunk. If the trunk is too tall, it can also be covered down to the second union. Tie the top tightly with string, and also tie the lower opening of the plastic bag tightly with string. Putting a plastic bag over the branches and trunk can promote early sprouting of the terminal buds of the saplings, and the tree body will have a large number of shoots. This can significantly improve the survival rate of planting and can prevent damage by June beetles. When the terminal buds of the saplings have sprouted to about 3.0 cm, first cut open the top for ventilation so that the saplings inside the bag gradually adapt to the external environment. After two or three days, untie the string at the bottom, and remove the plastic bag completely in the evening. When removing the plastic bag, do not do it too early, too hastily, or too late.
If the plastic bag is removed too early, the buds growing on the saplings may be damaged by pests such as June beetles; if the plastic bag is removed too hastily, the newly grown young leaves are exposed from a high-temperature, high-humidity environment to a dry environment, and the leaves are easily damaged, leading to drying up; if the plastic bag is removed too late, the temperature inside the plastic bag is very high, which can easily scorch the leaves.
5 Bud notching
The best time is before the tree body buds. If bud notching is done too early, long branches are likely to grow; if bud notching is done too late, more short branches will grow. After the Red Fuji apple sapling trunk is headed, it is not necessary to notch buds on the branches within 20.0 cm of the cut, and it is also not necessary to notch buds on the main trunk within 50.0 cm from the ground. For the remaining buds on the branches and trunk, make a cut above each bud with a knife or scissors every 5.0-6.0 cm. When notching buds, pay attention to the direction of the notched buds, arranged in a spiral, and make the shoots that emerge uniform in thickness. When notching buds, pay attention to making a "blind cut" above the bud, cutting through the cortex to the xylem, but do not injure the xylem too deeply. The notching knife should be dedicated and often disinfected to avoid infecting the branches and trunk with diseases when making cuts. In spring when it is windy and the climate is dry, the notching wounds are best placed on the leeward side to prevent the occurrence of rot disease.
6 Shoot removal from the tree body
After the saplings bud, promptly remove the young shoots growing from the interstock and rootstock to ensure that nutrients are supplied in a concentrated way to the cultivar scion and to accelerate vigorous growth of the cultivar scion.
7 Timely supplemental watering after planting
After the saplings are planted, judge whether another irrigation is needed according to the soil moisture content. If water is lacking, irrigate again about 15 d after planting to improve the survival rate of the saplings after planting and ensure vigorous growth of the young trees. In drought-prone areas with little rain from May to June, special attention should be paid to timely supplemental watering.
8 Pest and disease control
Adhere to the pest and disease control method of "prevention first, integrated control." For orchard sites where the saplings were not disinfected against the corresponding pathogens before planting, spray the whole orchard once with 5°Bé lime sulfur mixture after the fruit trees are planted and before the saplings begin to bud. When the new leaves of the saplings begin to spread out, if aphids occur, promptly spray for control, or choose insecticides such as imidacloprid acetamiprid, imidacloprid, and pirimicarb mixed with foliar fertilizer and spray continuously 3 times, which can completely eliminate them; when tortricid moths are found, promptly control them. Spraying 1,500 times diluted diflubenzuron No. 3 in early May can effectively control them. After mid-July, early defoliation disease is likely to occur. According to the disease incidence on the leaves, spray agents such as Daconil M-45 and 1.5% polyoxin. Generally, spraying 3 times is sufficient, and the late-stage leaf retention rate can be above 92%; if the leaf edges of young trees are found to be dry and the terminal leaf tips are wilting, choose 50% carbendazim 600 times dilution or 70% thiophanate-methyl 800 times dilution for root irrigation.
9 Fertilization management
When the branches of newly planted fruit trees grow to about 15.0 cm, apply some fast-acting nitrogen fertilizer to the soil. Urea can be chosen as the fertilizer. Apply 0.1 kg of urea per Red Fuji apple tree, and apply another 0.1 kg after 20 d. During the growing season, spray foliar fertilizer two or three times to promote growth, or choose to spray a 0.2%-0.3% urea aqueous solution. In the growing season, starting in early May, spray 0.3% urea once about every 10 d, continuously 3 times, which can effectively supply the nutrients needed for sapling growth; in mid-August, spray 0.5% monopotassium phosphate to increase the potassium content of the leaves and prompt the leaves to stop growing; from late September to early October, apply base fertilizer. Slow-release fertilizers can be chosen, such as decomposed organic fertilizer and farmyard manure. Apply 10.0 kg of organic fertilizer and 15.0 kg of farmyard manure per small tree. The application method can be circular, radial, or trench application.
10 Intertillage and weeding
Intertillage and weeding are mainly carried out from April to September. After each irrigation and after heavy rain, timely hoe and loosen the soil so that the surface soil becomes fine, loose, and breathable and does not harden; in dry weather, weed and loosen the soil once every 15 d, which helps resist drought and preserve moisture. Carry out the last weeding and soil loosening of the year in early to mid-September, with a depth that does not affect root growth, generally 5.0-10.0 cm. In summer, when temperatures are high and there is abundant rain, weeds proliferate. When hoeing weeds, hoe shallowly to drain moisture and preserve soil moisture. When using mechanical weeding, keep 0.5 m away from the trunk, and never injure the bark of the saplings. Near the saplings, hoe lightly and shallowly to avoid damaging the sapling roots; between the plants and rows, hoe deeply. Eliminating weeds can prevent the tree body and weeds from competing for water and nutrients, reduce water loss, and improve soil moisture conditions. Intertillage and weeding can also improve soil permeability, increase the frequency of microbial activity in the soil, and promote root growth.
11 Reasonable intercropping
In newly planted fruit tree orchards, reasonable intercropping can be chosen between the rows 1-3 a after planting to improve land utilization. Green manure can be planted between the rows to increase fertilizer sources. The main green manure crops include clover, hairy vetch, and ryegrass. Low-stalk crops can also be planted between the rows, such as potatoes, beans, and peanuts; it is forbidden to plant tall-stalk crops, deep-rooted crops, and crops with high fertilizer demands, such as sorghum and corn, as well as radishes and Chinese cabbage that need large amounts of fertilizer and water in autumn. When intercropping, attention should be paid to leaving a nutrient strip, generally about 1.0 m for one-year-old trees. Practice crop rotation when planting, and pay attention to strengthening fertilizer and water management.
12 Irrigation before freezing
Irrigate after leaf fall and before the soil freezes, to help the saplings overwinter safely.
13 Winter management
In winter, the temperature is relatively low, and newly planted saplings must receive special treatment to ensure their survival. For young trees planted in the current year or with relatively small tree bodies, soil mounding for cold protection can be carried out. That is, before the soil freezes, gently bend the young tree down. To prevent breakage, build a firm mound of soil on the side to which it will be bent down, make the top contact the ground, then cover it well with soil. The soil covering thickness is 20.0-40.0 cm. Be careful to cover the saplings tightly with soil, with no air leaks. After the soil thaws in late March of spring, promptly remove the cold-protection soil and straighten the young trees.