High-yield planting techniques of sweet potato

Sweet potato, also known as sweet potato, kudzu, sweet potato, etc., is an annual or perennial entangled herbaceous vine that can form root tuber in leguminous sweet potato genus. It originates in tropical America and is widely distributed in tropical areas of the Eastern Hemisphere. It is commonly cultivated in southwest provinces of China. Take its underground root tuber for raw food or cooked food. Its cultivation economic value is slightly low, but its nutritional value is not cheap. Let's take a look at the high-yield planting technology of sweet potato together.

Sweet potato growth habits

Sweet potato is a thermophilic and light-loving vegetable. It requires higher temperature conditions in growth period, 30℃ in germination period, and 25~30℃ in aboveground and flowering and pod setting period. The root tuber growth and development has wide adaptability to temperature, and can expand and grow under lower temperature conditions. However, if the temperature is lower than 15℃, the growth and development will be inhibited. The requirements for soil are stricter. Suitable soil conditions can obtain high yield and high quality. It requires deep, loose and well-drained loam or sandy loam soil, which is not suitable for planting on clay and poor permeability soil.

Sweet potato seed selection and soil preparation

The edible part of sweet potato is underground root tuber, so it is appropriate to choose sandy loam with deep soil layer, good drainage, medium fertility and strong water conservation fertility. After harvesting, soil preparation is carried out. The shape of sweet potato root tuber is related to variety, soil and cultivation. If the flat round variety is cultivated too deeply, the fleshy root will run down and form a long root. The fiber increase will lead to the quality decline. Generally, it is appropriate to cultivate 17~20 cm, while the sandy loam soil is only 13~17 cm. The spindle hammer shape can be slightly deeper. Plant ash 500 kg and decomposed manure 2000~3000 kg are applied per mu. 15 days before sowing, the soil will be broken and raked flat to make a high ridge of 1.2~1.3 meters wide, and the depth of the ridge is about 25 cm to facilitate drainage.

Cultivars of sweet potato

1. Early maturity species: medium plant growth potential, small leaves, early root swelling, short growth period. Root tuber oblate or spindle shape, thin skin, less fiber, single root weight 0.4~1 kg, fresh or fried food. Its varieties are Guizhou Huangping sweet potato, Sichuan Suining sweet potato, Chengdu Muma Mountain sweet potato, Taiwan Malay species, Guangdong Shunde Kudzuvine, etc.

2. Late-maturing species: strong growth potential, long growth period and late maturity of root tuber. Root tuber flat spindle or conical, thick skin, fiber, starch content, less water, single root weight of 1~1.5 kg, the largest can reach more than 5 kg. Suitable for processing powder. Commonly used varieties are Guangdong Zhanjiang big Kudzuvine, Guangzhou suburbs late sand Kudzuvine, Taiwan conical species and so on.

Sweet potato planting method

1, germination: sweet potato seeds hard, dry seed germination slow and not neat, production on the use of germination. Germination should be selected before the seeds, select mature, plump and fresh seed. Soak seeds for 10~12 hours before germination, put them in a warm box at 25~28℃ after water absorption and expansion, rinse them once a day, select the germinated seeds for sowing after 4~5 days, and sow them in 2~3 times.

2. Sowing: Sweet potatoes are generally sown, and the sowing methods can be divided into two types: climbing planting and support planting. Climbing planting is generally 50 cm row spacing, 33 cm plant spacing, 1 ~2 seeds per hole, 3000 plants per mu, about 2 kg seed amount. The support planting adopts deep groove and high ridge, the ridge height is 20~ 25cm, the groove width is 50cm, the ridge surface is 90cm, two rows are planted in each ridge, the row spacing is 50cm, the plant spacing is 33cm, 3~4 seeds are placed in each hole, the seed consumption per mu is 2.5~ 3.0kg, the soil is covered with 2~ 3cm, and the seedlings can emerge 15 days after sowing.

Field Management of Sweet Potato

1. Thinning and supplementing seedlings: seedlings emerge 15 days after sweet potato sowing, thinning and supplementing seedlings are carried out after the first pair of basal leaves appear, 1~2 seedlings are reserved in each hole, and 1 seedling is finally fixed. Replenishment seedlings should be timely, should choose cloudy days will be transplanted seedlings with soil mass.

2. Intertillage and weeding: sweet potato should pay close attention to intertillage and weeding before seedling height is 7 cm to lateral vine laying. Intertillage should be shallow, and roots should not be injured. During intertillage, soil can be cultivated 4~7 cm, so as to avoid exposing fleshy roots to the soil, turning green in color and deteriorating in quality. However, it is also forbidden to cultivate soil too deep, and root roots are easy to be long.

3, water and fertilizer management: sweet potato seedlings should be loosened and topdressing in time, each loose soil, irrigation of human excrement, promote its early hair, to the middle of June when the root tuber expands again topdressing. In case of drought, pay attention to watering. In case of heavy rain, timely drainage should be carried out. If waterlogging occurs in the field, it is easy to cause brown skin color or root rot of sweet potato, affecting its yield and quality.

4, flower picking: sweet potato in 5~6 nodes began to flower inflorescence, followed by vine elongation, almost every node of inflorescence, such as its flowering, then the pod is full of nutrients, the root is not easy to hypertrophy. Therefore, in addition to those who want to keep seeds, when they see inflorescences, they should be cut off immediately, and their leaves should be retained for photosynthesis, up to 2 to 3 times. Picked at 18~24 leaves of the main vine, the vine stopped growing after picking.

5, pruning frame: When the sweet potato seedlings grow to 30 cm high, insert a small mangosteen or cotton stalk in each hole, set up a herringbone frame, tie the adjacent sweet potato seedlings together and let the vine climb the shelf.

6. Harvest and seed retention: Generally, the fleshy roots can be harvested after 5~6 months after sowing, the early and medium hot varieties in the Yangtze River Basin can be harvested in September, and the medium and late mature varieties can be harvested from late October to early November. Raw root tuber should be early harvest, root crisp, juicy, sweet, but not resistant to storage. Mid-late maturing varieties of sweet potato thin skin, frost resistance, should be harvested before frost. The average yield per mu can reach more than 3000 kg.

Sweet potato pest control

1. Sclerotium disease

[Harm] Harm sweet potato seedling stem base and adult plants. Seedling stem base was water-like rot, can cause damping-off, adult plant damage in the near ground stem, petiole and leaves occurred water-like light brown spots, the edge is not obvious, often cause leaf or stem base rot.

[Control] At the initial stage of disease, spray 30% Huiheshixing WP 800~1000 times solution, 20% iprobiotics·carbendazim suspension 1500~2000 times solution or 40% Sclerotium WP 1000 times solution for control.

2. Virus disease

[Harm] Harmful sweet potato leaves. The diseased leaves turn yellow, and the upper leaves of the plant turn yellow completely when it is serious, forming yellow at the top and green at the bottom. The plant is dwarfed and accompanied by obvious deciduous leaves.

[Control] It can be sprayed with 800~1000 times solution of 20% copper guanidine acetate wettable powder, 2000 times solution of 1.6% amine ester solution or 500 times solution of 1.45% virus.

3. Pests on the ground

[Hazard] Sweet potato ground pests include Spodoptera litura, cabbage moth, diamondback moth, bean leaf roller, etc., mainly damaging sweet potato leaves.

[Control] It can be sprayed with 3000~5000 times solution of 20% chlorantraniliprole suspension and 1500 times solution of chlorfenapyr at the young larva stage.

4. Underground pests

[Hazard] The underground pests of sweet potato include grubs, ground tigers, mole crickets, earthworms, etc., mainly harming the root tuber of sweet potato.

[Control] After the main vine is picked and the root tuber is expanded, the root can be irrigated twice with 50% phoxim EC 500 times or 40% chlorpyrifos EC 800~1000 times.