Detailed Explanation of Pecan Planting Techniques and Management Methods
The pecan is the fruit of the American hickory, native to the United States and northern Mexico on the North American continent, and has now become one of the world's nut tree species. It is also cultivated in the ** Uyghur Autonomous Region of China, and small-scale trial planting has begun in Zhejiang Province. The fruit is rich in nutrients and delicious, a rare and tasty nut with high planting prospects. Let's take a look at the pecan planting techniques below!
Pecan Planting Conditions
1. Temperature conditions: Pecans prefer a warm and humid climate, with an optimal annual average temperature of 15.2°C. They can tolerate a maximum temperature of 41.7°C and are relatively cold-hardy, suffering no frost damage even at -15°C. However, low temperatures during the flowering period will affect flowering, pollination and flower development.
2. Water requirements: Pecan growth requires relatively large amounts of water, with different water needs at different phenological stages throughout the year. Generally, moderate rainfall is required before flowering during the spring shoot growth period. From late April to mid-May during the flowering period, continuous rainy weather should be avoided. From June to September, which is the fruit and naked bud development period, sufficient and evenly distributed rainfall is required.
3. Light conditions: Pecans are not particularly demanding regarding light. Young trees require a shaded environment, so seedling cultivation requires artificial shading. Adult trees grow poorly on sunny, dry and barren south-facing slopes.
4. Soil requirements: The ideal soil for pecan planting is loose, gravelly loam rich in humus derived from weathered limestone. The best soils are dark oil-black soil and yellow soil developed on limestone, as well as yellow soil developed on sandstone, slate and shale. Red soil and sandy soil are not suitable for growth.
Pecan Propagation Methods
1. Seed propagation: After harvesting the fruit, spread it in a ventilated indoor area. Once most of the outer husks have split open, remove the seeds. Sowing can be done in both spring and autumn, but autumn sowing is less safe than spring sowing because seeds are easily eaten by rats and birds. Sometimes winter drought causes seeds to lose water, resulting in a low germination rate. Autumn sowing is typically completed before the soil freezes in autumn. Spring sowing should be done early, preferably in mid-March. If spring sowing, the seeds must undergo sand stratification treatment.
2. Grafting propagation: The rootstock used for grafting is generally walnut. In the cold regions of North China, Manchurian walnut is used; in the Yangtze River basin, wild walnut is mostly used; in Shandong and Shaanxi, Chinese wingnut is used. Scions are collected from superior individual trees, selecting plump and robust vegetative branches from the outer canopy, 30-40 cm long and 1-1.5 cm thick. Plump and full buds from the middle and lower parts of the scion are used as grafting buds.
3. Cutting propagation: Pecan cutting propagation usually uses 1-year-old robust branches. The cuttings are 17-20 cm long. With standard cutting methods, the survival rate exceeds 90%.
4. Root cutting propagation: Roots are collected when seedlings are lifted from the nursery, then heeled in temporarily. Cuttings are made in spring. The root cuttings should be 1 cm in diameter and 10 cm long, preferably planted in beds. The upper cut end of the root must be buried 0.5-1 cm below the bed surface.
5. Layering propagation: During the dormant period, robust branches from the base of the mother plant are bent down into the soil. After a period of time, they will root. The branches are then separated from the mother plant and transplanted for further cultivation.
Pecan Planting Techniques
1. Land preparation and fertilization: For pecan planting, select plots with deep, loose soil, sufficient water sources, and sheltered, sunny locations. The ideal spacing between plants and rows is 4×5 m to 7×8 m. Planting holes should be 1-1.5 m in diameter and 1-1.2 m deep. Topsoil and subsoil should be kept separate. First place a layer of straw at the bottom of the hole, then cover with topsoil to 20 cm. Add 50 kg of organic fertilizer, 20 g of Jiadi powder, and 500 g of superphosphate, and mix thoroughly with the soil.
2. Transplanting: Pecan transplanting is done after leaf fall or before bud break. Large seedlings should be transplanted with a soil ball. For 1-2 year old small seedlings, as many lateral roots and fibrous roots as possible should be retained, and they should be promptly dipped in mud slurry to prevent root dehydration that would affect survival. During the young tree stage, especially before the first winter after planting, measures such as burying the trunk and mounding soil should be taken to protect young trees from cold and winter dieback. Particularly in the cold winter regions of North China and Northwest China, whitewashing the trunk of large trees (with lime) helps prevent frost damage to the trunk.
3. Pruning and training: Early pruning of pecans should be light, retaining an appropriate number of main branches to promote early fruiting. When pruning, ensure the inner canopy is well-ventilated and receives light. In the early stage, branches in the upper canopy should be retained as much as possible, while the lower canopy can be gradually thinned. If necessary, overly dense large branches can be sawed off. The saw cuts must be smoothed and coated with a protectant to prevent decay. After entering the decline stage, all parts above where renewal shoots emerge on the canopy can be sawed off to cultivate the sprouted renewal shoots. All dead parts of the main branches of the declining canopy should be cut off entirely. When performing truncation renewal, it is best to combine it with deep plowing and fertilization.
4. Cultivation and weeding: Within 1-3 years of establishing a pecan orchard, crops such as soybean, corn and Atractylodes macrocephala can be intercropped. During intercropping, the orchard should be cultivated and weeded, and appropriate amounts of organic fertilizers such as burnt mud ash, cake fertilizer and barnyard manure should be applied. Additionally, 1-2 times per year between July and August, weeds, shrubs, thorns and vines in the woodland should be cut down. The cut weeds should be used to cover the woodland floor. In winter, the mulch should be plowed into the soil to increase soil fertility.
5. Fertilization and fruit retention: Before spring bud break each year, apply about 30 kg of urea per mu. During the fruit enlargement period, apply 80 kg of fruit-tree-specific fertilizer. In autumn, apply 3000 kg of base fertilizer. After entering the fruiting stage, increase fertilizer application based on the fruiting situation. Foliar fertilization can be done once every 15 days or so in combination with pesticide spraying. Spray 0.3% urea during the early and late growth stages, and spray 0.3% monopotassium phosphate in June-July. In winter, water thoroughly for overwintering and bud break. During the rainy season, drain promptly to prevent waterlogging. Fruiting trees should be fertilized twice a year. In February, open radial trenches along the tree drip line and apply 20 kg of corn stalks and 5 kg of night soil per tree. In July, apply mainly NPK compound fertilizer at 0.2 kg per sq m.