The latest course of high-yield planting techniques and methods of sweet potato

Sweet potato, also known as sweet potato, kudzu, sweet potato, etc., is an annual or perennial twining herbaceous vine that can form tuberous roots in the genus Leguminosae. It is native to tropical America and is now widely distributed in the tropics of the Eastern Hemisphere. It is commonly cultivated in various provinces in southwestern China. Take its underground root for raw 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 techniques of sweet potato.

Growth habits of sweet potato

Sweet potato is a temperature-loving and light-loving vegetable, which requires a higher temperature in the growing period, 30 ℃ in the germination stage, and 25-30 ℃ in the aboveground and flowering and podding stages. The growth and development of root tuber has a wide adaptability to temperature and can expand and grow at lower temperature. However, when the temperature was lower than 15 ℃, the growth and development was inhibited. The requirement of soil is strict, and the suitable soil conditions can obtain high yield and high quality. loam or sandy loam with deep, loose and good drainage is required, which is not suitable for planting on the soil with poor clay weight and permeability.

Cultivation, selection and preparation of sweet potato

The edible part of sweet potato is underground root, so sandy loam with deep soil layer, good drainage, medium fertility and strong water conservation and fertility should be selected. After the previous harvest, soil preparation was carried out. The root shape of sweet potato tuber is related to variety, soil and tillage. if the flat round variety is cultivated too deep, the fleshy root goes down to form a long root, and the increase in fiber leads to a decline in quality. it is generally appropriate to plough 17-20 cm, while sandy loam soil is only 13-17 cm. The spindle shape can be a little deeper. Apply 500 kg of plant ash and 2000-3000 kg of rotten barnyard manure per mu. 15 days before sowing, the soil was broken and raked flat to make a high border with a width of 1.2 to 1.3 meters, with a depth of about 25 centimeters, to facilitate drainage.

Cultivated varieties of sweet potato

1. Precocious species: the plant growth potential is medium, the leaf is smaller, the tuber root expands earlier, and the growth period is shorter. Root flat round or spindle-shaped, thin skin, less fiber, a single root weight of 0.4 kilograms, 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 kudzu and so on.

2. Late mature species: the growth potential of the plant is strong, the growth period is long, and the root tuber matures later. Tuber flat spindle-shaped or conical, thick skin, more fiber, high starch content, less moisture, a single root weight of 1 to 1.5 kg, the larger can reach more than 5 kg. Suitable for processing and milling. The commonly used varieties are big kudzu in Zhanjiang, Guangdong, Chi Sha Kudzu in the suburb of Guangzhou, conical species in Taiwan and so on.

Sowing method of sweet potato

1. Sprouting: sweet potato seeds are hard, dry seeds sprout slowly and unevenly, and sprouting is often used in production. Seeds should be carefully selected before budding, and seeds that are old, full and fresh should be selected. Soak the seeds for 10 hours for 12 hours before sprouting, soak them in a 25: 28 ℃ incubator and rinse them once a day. After 4-5 days, the germinated seeds are sowed and sowed in 2-3 times.

2. Sowing: sweet potato is generally used for direct seeding, and the sowing methods can be divided into two types: climbing planting and support planting. Generally, the row spacing is 50 cm, the plant spacing is 33 cm, there are 2 seeds per hole, 3000 plants can be planted per mu, and the amount of seed used is about 2 kg. The support planting adopts deep trench and high border, the height of the border is 20cm 25 cm, the width of the ditch is 50 cm, the surface of the border is 90 cm, 2 rows are planted on each border, the spacing between rows is 50 cm, the distance between plants is 33 cm, there are 3-4 seeds per hole, the amount of seeds per mu is 2.5-3.0 kg, the cover soil is 2-3 cm after sowing, and the seedlings can emerge 15 days after sowing.

Field management of sweet potato

1. Seedling supplement: 15 days after sowing, sweet potato seedlings were unearthed. After the appearance of the first pair of basal leaves, interseedling and supplementary seedlings were carried out, leaving 1 seedling in each hole, and finally 1 seedling was fixed. The seedlings should be replenished in time, and the seedlings should be transplanted with soil masses on a cloudy day.

2. Intermediate ploughing and weeding: sweet potato should be ploughed and weeded before the seedling height is 7 cm to the side rattan paving. The middle ploughing should be shallow, and the roots should not be hurt. The fleshy roots can be cultivated 4cm and 7cm in order to prevent the fleshy roots from exposing the soil, the color and luster will turn green and the quality will become bad. However, do not cultivate the soil too deep, and the roots are easy to show long shape.

3. Water and fertilizer management: sweet potato should loosen the soil and topdressing in time at the seedling stage, loosen the soil every time, irrigate human feces and urine to promote its early development, and re-apply topdressing when the root expands in the first and middle of June. In case of drought, we should pay attention to watering. In case of heavy rain, it should be drained in time, if waterlogging occurs in the field, it is easy to cause sweet potato skin brown or root rot, affecting its yield and quality.

4. Beating flowers and picking hearts: sweet potato begins to draw inflorescences at 5-6 nodes, and then with the elongation of vines, almost every node inflorescence, if it is allowed to blossom, the pods are wasted and nutrients are wasted, and the roots are not easy to enlarge. Therefore, in addition to those who want to keep the seeds, as soon as the inflorescence occurs, it should be cut off immediately and the leaves should be retained for photosynthesis, up to 2-3 times. Pick the heart at the 1824 leaves of the main vine. After picking the heart, the vine stops growing.

5. Pruning and scaffolding: when the local melon seedlings grow to 30 cm high, insert a small mangosteen or cotton stalk in each hole, build a herringbone frame, tie the adjacent sweet potato seedlings together and let the vines climb on the shelf.

6. harvesting and remaining seeds: the fleshy roots of sweet potato can be harvested after 5 ~ 6 months after sowing, the early and medium-hot varieties in the Yangtze River basin are harvested in September, and the mid-late ripening varieties are harvested from late October to early November. The raw root should be harvested early, which is crisp and tender, juicy and sweet, but not resistant to storage. The middle and late maturing varieties of sweet potato have thin skin and are not resistant to frost, so they should be harvested before frost. Generally speaking, the yield per mu can reach more than 3000 kg.

Pest control of sweet potato

1. Sclerotinia disease

[harm] damage to the stem base and adult plants of sweet potato seedlings. The base of the stem of the seedling showed watery rot, which could cause sudden fall, and the damage of the adult plant often occurred on the stem, petiole and leaf near the ground, and the edge was not obvious, which often caused the base of the leaf or stem to rot.

[prevention and treatment] at the initial stage of the disease, spray control was carried out with 30% ash nucleus killing star wettable powder 800-1000 times, 20% isobacillus carbendazim suspension 1500-2000 times or 40% sclerotia net wettable powder 1000 times.

2. Virus disease

[harm] damage the leaves of sweet potato. The diseased leaves turned yellow, and in severe cases, the upper leaves of the plant all turned yellow, forming upper yellow and lower green, dwarfing the plant, accompanied by obvious deciduous leaves.

[prevention and treatment] 20% moguanidine acetate copper wettable powder 800 × 1000 times solution, 1.6% amine fresh ester water agent 2000 times solution or 1.45% virus Bike 500 times solution can be used for spray control.

3. Aboveground pests

The aboveground pests of sweet potato are Spodoptera litura, Spodoptera litura, Plutella xylostella, bean leaf roller and so on, which mainly damage the leaves of sweet potato.

[control] it can be sprayed with 20% chlorobenzamide suspension 3000-5000 times and fipronil 1500 times in the stage of young larvae.

4. Underground pests

The underground pests of sweet potato are grub, ground tiger, mole cricket, earthworm and so on.

[prevention and treatment] the roots can be irrigated twice with 50% phoxim EC 500 times or 40% chlorpyrifos EC 800-1000 times after coring of the main vine and at the initial stage of root expansion.