Detailed tutorial on the latest plum planting techniques and methods
The plum, also known as green plum, is a tree of the Dipterocarpaceae family, reaching up to 30m tall with a trunk diameter of up to 1.2m. The bark is blue-gray. Young branches and tender leaves are densely covered with stellate hairs. The inflorescence is a cymose panicle with small, white flowers. The fruit is nearly spherical, with 2 long and 3 short wings enlarged from the sepals. It is mostly distributed in Zhao'an, Fujian, Puning, Guangdong, Hainan, Taiwan, China, southeastern Anhui, Xuancheng City, Guangde County, Tongxi Township, Songchen Village, and Baitai Group. It grows from beaches at an altitude of 3-4m up to barren, thin mountain slopes at an altitude of 900m, and is more common at altitudes of 200-500m. It is also distributed in Thailand, Malaysia, Indonesia, and the Philippines. It is a national third-class protected vulnerable species. The main cultivar classifications of plum include green bamboo plum (green plum), white powder plum, soft-branch large-fruit plum, and other cultivars.
Site conditions
The altitude range of 1800m–2550m is suitable for the growth of fruit plums. Within this range, plots with good soil conditions, deep and fertile soil layers, convenient transportation, and good irrigation conditions should be selected, and planting in low-lying, wet, and poorly drained plots should be avoided.
Seedling requirements
Cultivated fruit plum seedlings must be of a pure cultivar, grafted from superior tree scions onto plum rootstock. The seedlings should be robust, with well-developed branches and axillary buds, a seedling height of more than 80cm, a root collar diameter of more than 0.8cm, complete main and lateral roots, many fibrous roots, and no pests or diseases, with strong stress resistance.
Planting time
Generally, fruit plums are suitable for field planting in spring, autumn, or the rainy season. According to the actual climatic conditions of Eryuan, field planting is suitable in the rainy season from July to August.
Field planting measures
1. Planting density: For flat land or gentle slopes with good soil conditions, use a spacing of 4m×4m between plants and rows, planting 42 plants per mu. For sloping land, to increase early yield, planned close planting may be carried out, using a spacing of 3m×4m between plants and rows, planting 55 plants per mu.
2. Planting pit preparation: According to standardized planting requirements, line-setting and point-marking are needed, that is, setting lines and points according to the designed plant and row spacing, with straight rows in both directions. The planting pit specifications require 80cm×80cm×80cm. When digging the pits, the topsoil and subsoil should be placed separately. When backfilling, apply 25-30kg of farmyard manure per pit, mix the soil and fertilizer evenly, and backfill to about 35cm, then place the mature soil (topsoil) downward and the raw soil (subsoil) upward, and backfill until it is 20cm-30cm above the ground, and make a circular tree basin.
3. Planting method: First, determine the center position of the planting pit as the planting point, then dig a hole 30cm deep and 40cm wide. Next, after removing the binding material from the selected grafted seedling, place the seedling upright in the planting hole, let the root system distribute evenly in the hole, gently cultivate soil over the roots, and after covering, gently lift the seedling so that the roots spread out and fully contact the soil. While filling the soil, press it firmly, taking care that the graft union is exposed 5-10cm above the ground and the tree basin is 20cm above the ground. After watering thoroughly to settle the roots, cover with plastic film. If any seedlings die within one month, they should be replanted promptly.
Soil management
1. Expanding holes and improving soil
This means improving the soil outside the planting pit. It is generally carried out in the autumn of the following year when applying base fertilizer. Dig pits at the edge of the tree canopy and then backfill with base fertilizer. The base fertilizer accounts for 70% of the annual fertilization amount. As the tree canopy expands year by year, fertilizer is applied outward in holes to achieve the effect of deepening and maturing the soil.
2. Cultivation management
Cultivation management mainly includes mounding soil to protect roots, cultivation, and weeding. Because fruit plum roots are shallow and leaves fall early, attention should be paid to deep plowing to mature the soil and guide roots deeper into the soil, so as to thicken the root soil layer, prevent exposed roots from being sunburned, and conserve moisture. Generally, in autumn during deep plowing and loosening of the soil, fertilized soil is applied at the same time, and weeding is carried out in a timely manner according to the local climate and the number of weed species in the soil, keeping the soil in the tree basin loose and free of weeds.
3. Reasonable intercropping
Within 1—3 years after field planting, short-statured crops such as vegetables and beans or green manure may be intercropped between rows, so as to support the orchard with the orchard.