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Typical examples of efficient cultivation of greenhouse tomatoes
Hou Wang Zhai Village, located in Houdian Town, Hebei Province, China, has become a model for sustainable agricultural practices. In 2002, Zhangwang Wang led the construction of a large semi-subterranean solar greenhouse with an actual area of 8 meters by 50 meters. This project involved 50 local farmers who built a total of 60 greenhouses. The facility adopted a long-term winter cultivation model, incorporating advanced high-efficiency farming techniques, along with rainwater harvesting and water-saving irrigation systems.
Over three consecutive years, the yield per greenhouse reached between 9,000 to 11,000 kilograms, equivalent to 15,000 to 18,000 kilograms per 667 square meters. Each greenhouse consumed approximately 180–220 cubic meters of water during the growing season (from August 20 to June 30), resulting in an annual revenue of 10,000 to 1.5 million yuan per greenhouse. Farmers earned a profit of 2.1 to 25,000 yuan per square meter, or about 1.4 yuan per kilogram of tomatoes. The return on water usage was around 70–80 yuan per cubic meter, making this system highly efficient and economically viable.
The main cultivation techniques include:
1. **Choosing the Right Variety**: Based on climate conditions and market demand, the Israeli Heisela company’s FA-189 variety was selected. It is an indeterminate type, resistant to low temperatures and low light, with hard fruits that are easy to store and transport.
2. **Nursery Timing**: Seedlings were started between July 15 and 25, with a seedling age of 25–30 days. This timing ensures strong growth before transplanting.
3. **Seed Treatment and Seedling Care**: Seeds were soaked in fresh water for 3–4 hours, then in a 10% trisodium phosphate solution, followed by another 3–4 hours in fresh water. After sowing, they were covered with 1 cm of soil and old newspaper. Healthy seedlings had a height of 15–20 cm, a stem thickness of 0.5 cm, and 3–4 true leaves after 25–30 days.
4. **Soil Preparation**: Before planting, the soil was tested and found to have 1.5–1.8% organic matter, 65 mg/kg available nitrogen, 10.5 mg/kg available phosphorus, and 160 mg/kg available potassium. Fertilizers included 1,000 kg of high-quality compost, 2 kg of dry chicken manure, 100 kg of triple compound fertilizer (N15%, P15%, K15%), 80 kg of urea, and 60 kg of potassium sulfate. The soil was prepared into wide rows (80–100 cm) and narrow rows (40–60 cm).
5. **Transplanting Time**: Transplanting usually took place around mid-August, with a planting density of 2,000–2,200 plants per 667 square meters. After planting, a 500-fold solution of Primo 500 and rooting agent was applied to prevent damping-off and root rot while promoting healthy root development.
6. **Post-Planting Management**:
- **Top-Dressing and Watering**: When the first fruit cluster reached the size of a walnut (diameter 4–5 cm), the water-fertilizer joint application began. Urea (8–10 kg) and potassium sulfate (10 kg) were applied 8–10 times, with 8–10 cubic meters of water each time.
- **Pruning**: A single-stem pruning method was used. When the sixth node showed flowering buds, two leaves were removed. Once 50–60% of the main fruit was harvested, side branches were managed for secondary fruiting. Typically, 2–3 pruning sessions were performed, resulting in 20–24 fruit layers.
- **Flower Protection and Fruit Setting**: Anti-dropping agents (30–50 mg/kg) or 2,4-D (15–20 mg/kg) were sprayed to increase fruit set and reduce flower and fruit drop. At flowering, 50% carbendazim or fast-inking was used to prevent botrytis.
- **Disease Prevention**: On the 7th day after planting, 80% Dasheng M-45 WP 500 times or 75% chlorothalonil wettable powder was sprayed. Amisidac 25% wettable powder was applied every 10 days. Disease management followed the principle of "comprehensive prevention, timely control, and rational use of chemicals."
This integrated approach has not only improved productivity but also ensured environmental sustainability and economic viability for the local community.