Cultivation techniques of sweet potato sprouts and vegetables

Sweet potato sprouts, also known as sweet potato leaves and sweet potato leaves, belong to the genus Sweet Potato of the Convolvulaceae. it is a variety of sweet potato seedlings with tender stems at the tip of sweet potato seedlings selected by artificial selection. In Hong Kong, it is still known as "vegetable queen", "longevity vegetable" and "anti-cancer vegetable". It is a real green vegetable product. Nutrition and health care function: sweet potato sprouts are nutritious, with 10-15 cm at the top of sweet potato vines and tender leaves and petioles per 100 grams. Sweet potato stem tips are rich in protein, carotene, vitamins, iron and calcium. According to laboratory analysis, the quality of stem tip crude protein is 21.1% of dry weight, 15.1% of dry weight, equivalent to that of pork and beef. The protein content of stem, leaf and stem tip is 2.7%, carotene is 5580 IU / 100g, vitamin C is 41.07mg / kg, calcium is 74mg / kg, iron is 4mg / kg, vitamin B1 is 3mg / kg, nicotinic acid is 6 to 10mg / kg, B6 is 2.1mg / kg. According to the detection of China Preventive Medical College, compared with 13 kinds of vegetables, such as celery, cabbage, spinach, Chinese cabbage, rape, leek, cucumber, eggplant, carrot, tomato and so on, among the 14 kinds of nutrients, 13 items, such as protein, fat, calories, cellulose carbohydrate, calcium, iron, phosphorus, carotene, vitamin C, B1, B2 and nicotinic acid, ranked first. Sweet potato stem tip is rich in mucin, which can protect the digestive tract, respiratory tract, joint cavity, membrane lubrication and vascular strength of human body. This substance can prevent arteriosclerosis caused by the deposition of lipids on the arterial wall, expand the atrophy of connective tissue of organs such as liver and kidney, and improve the immunity of the body. In addition, it also has health functions such as raising platelets, stopping bleeding, preventing night blindness, promoting intestinal movement, preventing constipation and so on. At present, sweet potato stem tip is listed as one of the most promising health longevity dishes in the United States. Japan, the United States and other countries even listed sweet potato stems as longevity food or space food. Germany called sweet potato leaves and tips as vegetable queens. It has health effects such as moistening intestines, defecating and lowering blood pressure. Cultivation methods: sweet potato has the characteristics of wide adaptability, strong stress resistance, drought tolerance, barren tolerance, plant absorption and regeneration ability, disease and insect resistance. Therefore, it is evergreen and grows vigorously in the south subtropics. Adopt all-organic cultivation, build a sunshade greenhouse, and cultivate with 45% shading black shading net. The seedlings can be directly cut and planted with sweet potato stems or top tender stems, drenched in water and moisturized, and can be picked after 15 days in summer and autumn and 30 days in winter and spring. If the stem tip of sweet potato is developed and processed into green vegetables and health food, its added value will be greatly improved. One planting can be picked all the year round, and the general yield per mu can reach more than 3000Mu 5000 kg. Picking standard: the buds of the products are between 10m and 15cm, the stems and leaves are green and glossy, no diseases and insect pests, no yellow leaves, no decay, no other pollution spots; packaging processing and preservation: vacuum packaging and cold storage.