Cultivation techniques of purple sweet potato

Sweet potato, also known as sweet potato, etc., is an annual plant of Convolvulaceae, which is planted in most parts of China except Qinghai-Tibet alpine region. In recent 20 years, more and more foreign research results show that sweet potato is rich in nutritional value. Sweet potato is rich in 18 kinds of amino acids, the content of dietary fiber is 10 times that of rice and flour, vitamin E is 9.5 times that of wheat, it is a physiological alkaline food, and it is necessary to maintain the acid-base balance of human health. Selenium-enriched purple sweet potato is a new sweet potato variety introduced from Provincial Academy of Agricultural Sciences in Pinghu City. After successful trial planting in 2007, it was tested by Agricultural Product Quality Safety Supervision and Inspection Center (Zhejiang) of Ministry of Agriculture. The organic selenium content per kilogram of fresh sweet potato reached more than 0.01 mg, and the anthocyanin content per kilogram of fresh sweet potato reached 200 mg. Regular consumption can improve immunity, lower blood pressure and protect liver.

purple sweet potatoes

I. Biological characteristics

Purple sweet potato likes warm climate environment. The suitable temperature for stem and leaf growth is 18~25℃, and it stops growing when the temperature is lower than 15℃. The optimum ground temperature for root tuber growth was 22~24℃, and the root tuber stopped expanding when the ground temperature was lower than 20℃. Purple sweet potato is a short-day crop, which needs sufficient light and high intensity. The suitable soil moisture content for purple sweet potato growing period is 60%~80% of the maximum field moisture content.

II. Cultivation techniques

1. variety selection

Purple sweet potato originated in Japan, the name Kawayama purple, Japanese researchers in the late 1990s breeding success. China began to introduce from 2002, and now there are many varieties of purple sweet potatoes cultivated in China, some of which are used for natural pigments, which are not suitable for fresh food, high starch content, less moisture, dry taste, more suitable for extracting pigments, processing whole flour, processing leisure food. There is a kind of selenium-rich purple sweet potato whose scientific name is "Yuzi 263". It is a new variety of selenium-rich purple sweet potato. Its skin is purple, the meat is purple and delicate, the water content is sufficient, sweet but not dry, and the taste is sweet and glutinous. It is an ideal coarse grain option for people. It is more suitable for fresh food. The most important thing is that it is rich in selenium, a trace element beneficial to human body.

2. Land selection and fertilization

Selenium-rich purple sweet potato is suitable for planting in rice fields with high terrain and convenient irrigation. Deep ploughing, small ridge and single row, ridge width 40cm, ridge height 25cm. Fertilization should master the principle of increasing base fertilizer, heavy potassium fertilizer and supplementary phosphorus fertilizer. Base fertilizer is mainly biological organic fertilizer, 300kg per mu, combined with appropriate compound fertilizer, 15-15-15 compound fertilizer applied 10kg per mu, strip application. Topdressing should be based on decomposed human excrement.

3. Early planting:

Selenium-rich purple sweet potato is generally planted once a year. When the field temperature is stable above 15℃, the earlier the better, and the spring sweet potato is generally better in the middle of May. At the latest, it can be planted before the end of July, but it will affect the yield of selenium-rich purple sweet potato.

Third, improve the quality of planting, reasonable density planting.

Select disease-free vine seedlings, large and small seedlings separated, buried three-leaf planting, seedlings inserted obliquely into the bed surface. Potato seedlings 20 cm long, obliquely inserted into the soil 3 nodes, exposed soil surface 2 nodes. After cuttage, use decomposed human excrement to ensure that the tree is alive. After cuttage survives, it is necessary to water frequently to keep the soil moist. According to different soil fertility and characteristics, the reasonable cutting density was determined, the plant spacing was generally 25 cm, the row spacing was 75cm, and the purple sweet potato seedlings were about 3500 per mu. Flat bed planting.

4. Strengthen field management.

(1)Grub prevention before planting. Available iron frog (3% phoxim granules) control, the dosage of 6 jin per mu, in the middle of each ridge ditch strip application, the best choice in the evening strip application.

(2)After planting, immediately use 150 times of acetochlor per mu for chemical weeding, the dosage is 100 g/mu, add 3 tubes of water for weeding, check seedlings 3-5 days after planting to ensure complete seedlings.

(3)In the early stage of growth, cultivation shall be carried out in time, generally 2-3 times of cultivation, combined with cultivation and ridging; selenium-rich purple sweet potato is most afraid of waterlogging, so it must be eliminated in time. When drought is severe, conditions permit timely drought relief. After closing the ridge, pull out the big grass.