Detailed Explanation of Labor-Saving Cultivation Techniques for Modern Peach Orchards in Southern China

Detailed Explanation of Labor-Saving Cultivation Techniques for Modern Peach Orchards in Southern China

Traditionally, southern peaches grown in Hunan Province and other southern provinces generally have low trunk heading, and the "one, three, nine" training system is adopted for tree shaping, resulting in canopy closure in later stages, early tree senescence, and inconvenience for field operations. To address these shortcomings, our research group conducted research on labor-saving cultivation techniques for modern peach orchards in southern China. The author believes that modern peach orchards in southern China should follow three basic requirements: first, labor-saving cultivation patterns, to improve light exposure, enhance quality, facilitate mechanical tillage, and promote wide-row planting and high-canopy cultivation technical measures; second, simplified tree management, with simplified pruning and simplified tree shapes as the main tree management cultivation measures; third, labor-saving soil and fertilizer-water management, using slow-release fertilizers, integrated fertilizer-water management, sod culture, and using grass to nourish the soil, promoting mechanized management. On the basis of meeting these three basic requirements, labor-saving cultivation techniques for modern peach orchards include:

1 High-standard orchard establishment

Peach is a tree that cannot tolerate continuous cropping. New peach orchards should be established on plots where peaches have never been planted before.

Dig planting trenches 80 cm wide and 40 cm deep. Before backfilling, first mix topsoil with organic materials at a ratio of 5:1. Organic materials can include rice husks, straw, sawdust, reed stems, cattle and sheep manure, weeds, mushroom residue, etc. Then uniformly mix in 5000 kg of organic fertilizer and 50 kg of superphosphate per 667 sq m. At the same time, measure the pH value of the mixed backfill substrate, and adjust the pH to 6.3-6.5 by adding quicklime. Backfill the prepared backfill substrate into a turtle-back shape and water thoroughly. Use high-ridge cultivation. Planting time is 30 days after backfilling. Straighten the root system, water thoroughly, and take care not to bury the graft union into the soil. Prune at a uniform height when planting. Advantages: The wide-row ridge planting with close spacing method facilitates machinery access to the orchard and saves labor.

2 Simplified tree management

Tree management cultivation measures mainly based on simplified pruning and simplified tree shapes. Simplified tree shapes and wide-row cultivation, transitioning from multiple scaffold branches to fewer scaffold branches:

(1) Simplicity and lightness: The main purpose of close planting is to use the advantages of the population to achieve early fruiting and early high yield. Without this purpose, close planting loses its meaning. Closely planted trees have a small tree body, and the load per individual tree is relatively light. There is no need to build a complex and strong multi-level framework. The tree structure is greatly simplified, pruning is light, and this is conducive to early fruiting. Sparse planting, on the other hand, must first cultivate a large and sturdy tree framework, with strict subordination relationships, and pruning cannot be light. Sparse planting with light pruning and long shoots can also achieve early fruiting, but the tree body expands slowly, and yield per unit area is low; moreover, the framework is weak with poor bearing capacity, making high yields difficult to achieve later.

(2) Combining promotion and control: "Tree growth depends on promotion, fruiting depends on control." Sparse-planted trees have large individual space and must be encouraged to fully expand in order to fully utilize land and light energy, so the early management of sparse-planted trees is basically promotion only without control. Close-planted trees mainly rely on the population to utilize space, and individual expansion is limited, so the management of close-planted trees involves both promotion and control (promote in spring, control in summer; promote roots, control canopy; promote lower, control upper; promote inner, control outer; promote main, control auxiliary; promote weak, control strong, etc.). Promotion only without control leads to delayed fruiting; control only without promotion leads to low yield. Only by promoting first and then controlling, both promoting and controlling, and combining promotion with control, can the appropriate balance be achieved to attain early fruiting and early high yield.

(3) Summer pruning as the main approach: Winter pruning is vigor-promoting pruning, which benefits strong trees. The framework cultivation of sparse-planted trees mainly relies on winter pruning. Summer pruning is vigor-reducing pruning, which benefits fruiting. Close-planted trees do not have strict requirements for the framework. With a focus on early fruiting and high yield, they mainly rely on summer pruning.

(4) Emphasis on population structure: Sparse-planted orchards have large space in the early stage, with minimal influence between individuals. Individual trees are relatively independent, each with its own character. More emphasis is placed on tree structure rather than rushing to consider population structure. Close-planted trees have a large population, with significant mutual influence between individuals, and population structure evolves rapidly. In addition to tree structure, population structure must be considered early on. With the "wide-row, close-spacing" planting method, each row of trees should be viewed as a single tree. Shaping methods that can be adopted: wide-row trunk shape training, espalier shape training, one-sided leaning shape training, Y-shape training, etc.

3 Key techniques for Y-shape cultivation of peach trees

Based on the team's current research mainly focused on Y-shape training, the author takes peach tree Y-shape training as an example, and its key techniques are as follows:

(1) Adopting Y-shape training requires an orchard site with sufficient light, facing the sun, sheltered from wind, loose soil, complete drainage and irrigation facilities, and convenient transportation on gentle slopes or flat land. Steep slopes are not suitable for Y-shape.

(2) Planting:

Timing: Plant after leaf fall in autumn, and try not to wait until the following spring. (High survival rate of cultivation, promotes and maintains root growth)

Row direction: North-south orientation is best, or according to the terrain.

Density: 1.2 m x 4.5-5 m, planting 110-122 trees per 667 sq m.

Planting treatment: For seedlings with a stem diameter of 1.0 cm and seedling height of 70 cm, after pruning the root system, use 50% carbendazim at 500 times dilution + 50% phoxim at 1000 times dilution to kill fungal and insect sources carried by the root system. Root dipping time is 10 seconds.

The ratio of main cultivars to pollinator cultivars should preferably be 4-5:1. On hillside plots, plant pollinator trees in a diagonal pattern; on flat land, plant one row of pollinator trees every 3-4 rows in a longitudinal pattern.

(3) Branch thinning

For newly planted finished seedlings, remove all first-year branches on the trunk. Do not shorten or head the central leader of the seedling; allow it to grow freely.

(4) Trellising

In the first year, use bamboo poles or wooden stakes to fix and straighten newly planted young trees to cultivate a strong trunk. In July-August of the second year, when the young tree trunk reaches 2.5-3.0 cm, according to the required angle and orientation for "Y"-shaped training, fix the young tree with thick bamboo poles and tie it to an angle of 25-30 degrees from the vertical, achieving one-time shaping.

(5) Topdressing

Fertilize according to N:P:K = 3:1:4. In the early stage, mainly nitrogen fertilizer; in the later stage, mainly potassium fertilizer. Apply organic fertilizer at "1 jin of fruit to 2 jin of fertilizer" in September-October of autumn. During the pit-hardening stage to the second fruit-swelling stage, strictly control nitrogen fertilizer application to prevent pit splitting. (Adjust according to soil fertility conditions) [Jishan Huayao]

(6) Irrigation

Peach trees are drought-tolerant and afraid of waterlogging. Watering should be done with small amounts and frequent irrigation. Never use flood irrigation. In the rainy autumn season, drainage work should also be done well to prevent waterlogging in the peach orchard that causes tree death.

(7) Training

Summer heading, renewal pruning, and branch thinning: In the first year of pruning, head the trunk at 50-60 cm, then select and retain two new shoots spaced 10 cm apart to cultivate two scaffold branches. New shoots below 50 cm from the ground are removed at the early bud-break stage. All other new shoots are pinched to control growth when they reach 15-20 cm in length, keeping the angle between the two selected scaffold branches at 50-60 degrees and allowing the two scaffold branches to grow naturally. During winter pruning, the two scaffold branch extension leaders are kept at 50-60 cm, and all fruiting branches are removed, keeping the heads upright for vigorous growth and good ventilation and light penetration. At the same time, combine with early summer heading and autumn twig twisting for control. Less heading in winter - mainly long-shoot thinning: During winter pruning, fruiting branches are cut to 30-50 cm, keeping 15-20 cm spacing on opposite sides and 30-40 cm spacing on the same side. All other first-year branches are removed. In the third year of winter pruning, the scaffold branch extension leaders, based on the heading in the previous two years, undergo long-shoot pruning in the third year. For small branches retained on main and secondary branches, keep one fruiting branch every 15-20 cm, maintaining fruiting branches on the same side at 30-40 cm or more.