I. Variety Selection and Planting Techniques
1. Variety Selection: Select varieties with a short fruit development period, early maturity, large fruit size, bright color, good taste, high pollen content, and high yield. Commonly used cultivars in production include Purple Amber and Special Early Red. The main cultivars and pollination varieties are planted in a 5:1 ratio to ensure effective cross-pollination and maximize productivity.
2. Planting Specifications: In greenhouses, plants are spaced at a height of 2 meters and 1 meter, with the first row placed 100 cm from the northern wall. The southernmost row is kept 80 cm away from the front wall to allow for proper air circulation and sunlight exposure.
3. Planting Hole Preparation: Dig planting holes that are 40 cm deep and wide. After filling the hole with topsoil, add 100 kg of organic manure and 2 kg of compound fertilizer per plant. Water thoroughly after planting to ensure good root establishment.
II. Tree Management
1. Tree Shape: The tree is trained into a spindle shape, with a height of 1 to 1.8 meters and a trunk height of 30 cm. It has 4 to 5 layers, with 12 to 15 main branches arranged parallel and evenly distributed. The main branches grow at an angle of 70° to 80°, with a length of 40 to 70 cm, which is ideal for the given planting specifications.
2. Summer Pruning: During summer, prune according to the desired tree shape by pinching buds, softening branches, twisting tips, and opening branch angles. This helps control upright growth and promotes better ventilation and light penetration. After harvest, prune back long branches to moderate ones, leaving a new shoot at the tip.
3. Winter Pruning: Focus on trimming long shoots, removing non-fruiting branches, crossing branches, overly dense branches, and upright branches on the back. This helps control tree height, maintain balance, and improve fruiting ability.
4. Chemical Control: Apply paclobutrazol in mid to late July to regulate growth and promote flower bud formation. Use a 15% paclobutrazol solution diluted 300 times, applying it once daily for seven days or up to three times if necessary.
5. Flowering Management: Assist pollination using artificial methods, feather hairpins, or bees to increase fruit set. Thin fruits twice: the first time three weeks after flowering to remove small, double, or crowded fruits; the second time five weeks after flowering, based on a target yield of 2000 kg per acre. Distribute remaining fruits evenly along the branches.
III. Pest and Disease Control
1. Disease Prevention: Greenhouse plums are prone to leaf spot. Before bud break, spray with 5°Bé lime sulfur. During summer, apply a 1:4:240 copper sulfate lime solution every 20 days to prevent disease spread.
2. Insect Pest Control: After warming, spray insecticides at 1500 times dilution during locust egg hatching. For spider mites, use 1500 times dilution of broom or 2500 times Qishaosu. Treat leaf roller moths with diflubenzuron at 1500 times dilution.
IV. Fertilization and Irrigation
After planting, create shallow trenches between rows (20 cm wide, 5 cm deep) for drainage, irrigation, and fertilization. In the early growth stage, apply fertilizer every 10 days—25 kg of ammonium bicarbonate and potassium dihydrogen phosphate during the budding to flowering phase. During the young fruit stage, use 25 kg of urea, diammonium phosphate, and potassium sulfate. After harvest, apply underground fertilization with 100 kg of ammonium bicarbonate or 50 kg of urea. In September, apply 3,000 kg of organic fertilizer, 30 kg of diammonium phosphate, 30 kg of potassium sulfate, and 30 kg of urea per acre. Water after each application. In addition, water 1–2 times based on soil moisture and loosen the soil after irrigation.
V. Temperature and Humidity Control
1. Temperature Regulation: Plum trees require 40–50 days of dormancy at 0°C–7°C for 1000–1500 hours. After leaf fall, start forced dormancy and ensure sufficient cooling before warming. After warming, adjust temperature by controlling ventilation. Ideal temperatures during key growth stages: 13–15°C during early bloom, 3–5°C at night, 18–20°C during the day, not exceeding 22°C. Nighttime should be 6–8°C. During fruit growth, daytime is 25–28°C, nighttime 10–12°C. During fruit coloring, maximum daytime temperature should not exceed 30°C, with nighttime 10–15°C. Remove plastic film when outside temperatures reach 10–12°C at night.
2. Humidity Regulation: Maintain 70% relative humidity from film removal to germination, 50% during flowering, 60–70% during fruit expansion, and 50% during fruit coloring. Adjust humidity through irrigation as needed.
VI. Fruit Harvesting
Harvest fruits when they are mature and ready. For long-term storage or transportation, pick about 80% ripe fruits. Avoid watering 10 days before harvest. Harvest in the morning after dew has evaporated, avoiding midday heat.
One-click Video Measuring Machine
One-click flash tester, also known as One-click fast measuring instrument and One-click fast image measuring instrument, is widely used in the measurement and detection of die-cutting products, mobile phone cover plates, mobile phone glass, PCB, springs, screws, precision hardware, machined parts, and other products. Once used, the one-button flash tester does not need a fixture, and the product can be placed arbitrarily. The full-size measurement of the product can be completed with one button, with high efficiency, high accuracy, and simple operation.
Fast Measuring Instrument,Fast Image Measuring Instrument ,One Button Measuring Instrument,One-Key Precision Detector
Zhejiang dexun instrument technology co., ltd , https://www.dexunmeasuring.com