What are the key techniques for high-yield yellow peach cultivation?
Among the many peach varieties, the yellow peach stands out. Beneath its yellow skin, the flesh is soft, glutinous and sweet. A good yellow peach can be smelled from far away, its rich aroma refreshing the heart. In recent years, the economic value of yellow peaches has risen markedly, and more and more people are growing them, but the actual growing process demands real effort from us. To achieve high yield of yellow peaches, you must master the following key cultivation techniques, so that the yellow peaches grown are large and sweet.
1. Variety selection
Choose excellent varieties suited to the local area, and pay attention to combining early-, mid- and late-maturing varieties. In areas far from large cities, mainly choose mid- and late-maturing varieties that store and transport well. Pollenless varieties must be given pollinizer trees, and pollen-bearing varieties should also be given pollinizer trees; generally the ratio of main variety to pollinizer variety is 5-8:1. Pay attention to choosing varieties and rootstocks with good resistance to pests, diseases and stress.
2. Nursery stock selection and planting
1. Nursery stock selection
Choose grafted seedlings with more than 3 main and lateral roots, a length of more than 20 cm, full growth, a seedling height of more than 80 cm, a base diameter of more than 1 cm, and a well-healed graft union. Never use nursery stock subject to quarantine pests. Use mountain peach, wild peach or Qingzhou honey peach, etc. as rootstocks.
2. Planting of nursery stock
Planting density is 1-2 m between plants and 5 m between rows; where mechanical operations are used, the in-row spacing may be appropriately reduced. Planting time is divided into spring planting or autumn planting. Spring planting is done after the soil thaws, followed by irrigation, then plastic film mulching to raise soil temperature. Autumn planting is done after leaf fall until before the soil freezes, with timely irrigation after planting, then plastic film mulching. The planting hole is 0.8 m in diameter and 0.8 m deep. Before planting, first soak the seedling roots in water to absorb enough moisture, lightly trim thick roots, disinfect with 5 degrees Baume lime sulfur mixture, dip in mud slurry and then plant. Before planting, apply 40 kg of decomposed organic fertilizer and 0.5-1 kg of diammonium phosphate per plant; mix the organic fertilizer and chemical fertilizer with the topsoil dug out, backfill into the hole, fill to about 25 cm from the surface, tread firm or irrigate first and wait for it to settle before planting; irrigate promptly after planting, and keep a tree basin of at least 1 m × 1 m. The planting depth should be based on the depth at which the seedling was covered with soil in the nursery.
3. Soil, fertilizer and water management
1. Soil management
Every autumn, deep plow between the rows to improve the soil, plowing 40-60 cm deep around the outer edge of the canopy. For young trees, green manure or crops such as beans can be intercropped between rows, and cultivation is done after each irrigation and rainfall. For mature trees, use sod culture between rows and clean cultivation or mulching within the rows. Plant mouse barley grass, white clover, ryegrass, etc. artificially or allow natural grass; when the grass between rows is 30-40 cm high, cut it by hand or machine, keeping the stubble height at 8-10 cm, cutting 3-4 times a year, and spread the cut grass over the tree basin.
2. Fertilizer management
Apply base fertilizer in autumn after the fruit is harvested (September-October), in combination with plowing and soil improvement. Calculate 150 kg of decomposed organic fertilizer per 100 kg of fruit, and mix in 1.2 kg of ammonium dihydrogen phosphate and 1.2 kg of potassium sulfate. Generally apply 3000-4000 kg of high-quality organic fertilizer per mu, mainly by trench application, with the application site within the canopy projection area. Fertilization methods include digging radial trenches, ring trenches or parallel trenches, with trench depth 30-45 cm, and irrigate after fertilizing. Topdressing is done before bud break and 1 week after flowering, applying 0.5 kg of urea per 100 kg of fruit in a ring trench 10 cm deep; at the hard-pit stage apply 0.3 kg of urea per 100 kg of fruit; at the fruit swelling stage apply 1.0 kg of potassium sulfate per 100 kg of fruit. Irrigate promptly after topdressing, and no topdressing is allowed within 30 days before harvest. For foliar topdressing, spray 4%-5% zinc sulfate before bud break; spray 0.2% borax solution once at full bloom; before the hard-pit stage spray 0.2% urea and 0.2% potassium dihydrogen phosphate. No foliar topdressing is allowed within 20 days before harvest. In production areas where conditions permit, fertilizer should be applied based on nutritional diagnosis according to soil and leaf analysis results.
3. Irrigation and drainage
Irrigate once before bud break together with topdressing, irrigate once at the hard-pit stage, no irrigation within 15 days before harvest, and irrigate well with winter freezing water before winter. Before the rainy season, clear the drainage system to ensure smooth drainage during the rainy season. Peaches fear waterlogging, so strictly prevent water accumulation in the peach orchard.
4. Training and pruning
(1) Winter pruning. At present, there are two methods of winter pruning in production: long-branch pruning and short-branch pruning.
(2) Summer pruning. Carry it out 3 or 4 times a year.
Training and pruning must ensure ventilation and light penetration. The peach tree is a light-loving species, and canopy coverage should be maintained at about 70%. In overly dense orchards, thin out or adjust the tree structure, and keep the light transmittance under the canopy >40%.
5. Pest and disease control
(1) Strengthening cultivation management, applying more base fertilizer, rational irrigation, controlling humidity, controlling nitrogen and increasing potassium, rational load, and enhancing tree vigor are the foundation for pest and disease control.
(2) Strengthen nursery stock quarantine, and use rootstocks, scions and nursery stock free of pests and diseases.
(3) Planting leguminous alfalfa between rows can fix nitrogen, increase soil fertility, improve the orchard microclimate and suppress weed growth, and is conducive to the reproduction of natural enemies of spider mites, aphids, fruit borers, etc. When the number of natural enemies reaches a certain level, cut the grass at the right time to force the natural enemies up into the trees to control pests.
(4) Bagging the fruit can control various fruit-feeding pests at the same time; spray insecticides and fungicides before bagging. During the growing season, promptly remove pest- and disease-damaged fruit and burn or bury them deeply in a centralized manner.
(5) Do a good job of orchard cleaning to reduce the pest and disease base. In late autumn and early winter, thoroughly sweep up fallen leaves, pick up all fallen fruit, promptly remove them from the orchard, scrape off old bark from the trunk, and scrape the loose bark clean until smooth. Collect all scraped bark and burn it in a centralized manner; after inspection, if there are many natural enemies, they may first be stored appropriately before disposal.
(6) Whitewashing the trunk during the dormant period of the fruit tree can protect the trunk, prevent sunscald and freeze damage, and has insecticidal and fungicidal effects. The first whitewashing is done after leaf fall until before the soil freezes, and the second in early spring. The main trunk is the main part to be whitewashed; young trees, large trees with incomplete canopies, diseased trees, the south side of the trunk and the sunny sides of branches should be whitewashed with emphasis. Do not apply it to the branch tips, to avoid burning the buds. The whitewash mixture can generally be prepared with 10 parts quicklime, 0.5 part sulfur powder, 0.2 part salt, 0.2 part animal oil and 35 parts water.