Kate apricot cultivated under a simple plastic greenhouse achieves maturity 30 to 40 days earlier than open-field cultivation, significantly boosting economic returns by 15 to 20 times. This method not only improves yield but also enhances fruit quality and market value.
1. Structure of a Simple Plastic Greenhouse The greenhouse is designed as a north-south oriented arch-shaped structure with a span of 10 meters and a length of 60 meters. Its maximum height reaches 2.5 meters, while the shoulder height is 1.5 meters. The framework consists of reinforced cement columns as vertical supports, with bamboo rafters used for arches and cantilever beams. There are five rows of columns, spaced 2.5 meters apart. Vertical columns are placed 1 meter apart, and the distance between side columns is 3 meters. A suspension beam is installed above the middle three rows of columns, with 20 cm suspension poles placed every 1 meter along the beam. Arches are erected on both side and suspension columns at 1-meter intervals. No drip film is used; instead, the greenhouse cover is tightly pressed together. A laminating line is placed in the center of every two arches, allowing for ventilation by opening a gap between the two sides near the shoulder area.
2. Cultivation and Management Techniques Soil conditions at the test site are ideal—sandy loam with excellent drainage and irrigation systems. Organic matter content ranges from 0.60% to 0.78%, and the pH level is between 7.1 and 7.3. The main variety grown is Kate apricot, paired with Italian No. 1 as a pollination tree at a ratio of 5:1. Planting density is initially high, with spacing of 1.0 meter by 2.5 meters. As the canopy expands, thinning is performed to increase spacing to 2.5 meters when the canopy closes.
Pruning follows a small trunk sparse or naturally happy tree shape. For easier management, the trunk can be raised slightly, but not exceeding 50 cm. Three to six strong branches are selected as main branches, with the tree height controlled 30 to 35 cm below the greenhouse film. Pruning is mainly done during the growing season. Before bud break, proper pruning is applied to missing branches, and buds and back shoots are removed promptly. Branches with angles less than 60 to 70 degrees are thinned out. When new shoots reach 15 to 20 cm, the tips are cut to limit growth and improve light penetration. After harvesting, drooping, dense, cross, and overlapping branches are pruned, and weak branches are shortened. In autumn, branches are opened to promote ripening. Winter pruning focuses on removing dense, diseased, and weak branches, with long fruiting branches over 50 cm being shortened.
The optimal time for covering and uncovering the greenhouse is late December and mid-April, respectively. By the end of April, the average temperature reaches 15°C, and the fruit is nearly mature.
Temperature management is critical. About 20 to 30 days before covering the greenhouse, the soil temperature is increased by 2 to 3°C to avoid adverse effects of low ground temperature. The ideal temperature range for different growth stages includes germination (10-20°C), flowering (12-23°C), young fruit (15-24°C), fruit enlargement (12-28°C), and fruit ripening (22-32°C). Adjustments are made through venting and opening windows.
Fertilization and irrigation are carefully managed. After covering the greenhouse, each plant receives 0.5 to 1 kg of NPK compound fertilizer, along with sufficient water. The tree crown is sprayed with 5% urea to boost nutrient levels and humidity. During flowering, 0.3% borax is applied. Three applications of active bio-organic fertilizer are used during the hard nucleus and fruit enlargement stages to enhance stress resistance and reduce physiological fruit drop. Potassium sulfate (0.2–0.25 kg per plant) is added during fruit enlargement to improve size and quality. In August and September, 50 kg of organic fertilizer per plant is applied to enrich the soil and support tree nutrition.
Flower and Fruit Management 1. Artificial Pollination: Due to high humidity and limited pollinators, artificial pollination is essential. Flowers are hand-pollinated using brushes between 8 to 11 am daily after blooming. 2. Fruit Thinning: Overloading can weaken the tree. Fruit thinning is performed about 20 days after flowering, with long fruiting branches retaining 3–4 fruits, medium branches 2–3, and short branches 1–2 or none. 3. Growth Regulators: Paclobutrazol is used to control excessive growth. A 15% solution diluted 300 times is sprayed twice in mid-July to regulate canopy development. 4. Pest and Disease Control: Lime sulfur is applied one week after larvae emergence and again before bud break to prevent pests. During flowering, insecticides and fungicides are used as needed, typically 1–2 times during the growing season.
Cnc Rotary Axis Calibrator,Cnc Rotary Axis Calibration,Machine Tool Calibration Tool,Machine Tool Calibration Instrument
Automated Precision Inc. , https://www.apiasean.com