How to get high yield when growing sweet potatoes?

Sweet potato, also known as sweet potato, is commonly known as sweet potato in some areas. It is also called red potato, red taro or white potato. It is an annual herb belonging to the order Tubulales, family Convolvulaceae. Sweet potato tubers have high nutritional value and are rich in protein, starch, pectin, cellulose, amino acids, vitamins and various minerals. The sugar content is approximately between 1.5% and 5%. There are many people in my country who grow sweet potatoes, so how can we get high yields from growing sweet potatoes?

1. Selection of improved varieties

In order to meet the demand for steaming, baking and early market launch of fresh potatoes, you can choose short-vine virus-free varieties favored by the market, such as "Qinshu No. 4" and "Qinshu No. 5". Targeting the high-end market in big cities, special sweet potato varieties can be planted, such as red heart varieties, black sweet potatoes, vegetable-type varieties, mini potatoes, etc., for example, "Red Heart 431", "Chestnut Fragrance", "Heart Fragrance" and "Black Potato No. 1". When processing the "three kinds of flour" (vermicelli, rice noodles, and rice paper ), high-starch varieties should be selected, such as "Meiying No. 1", "Qinshu No. 1", and "SL-19".

2. Soil preparation and ridging

The development of sweet potato roots and tubers requires sufficient oxygen, so land that has not been planted with sweet potatoes should be selected. The soil layer should be deep and loose, and the soil should be plowed at least 25 cm deep before winter. Sweet potatoes are suitable for ridge cultivation, which helps to increase ground temperature and facilitates irrigation and harvesting. The ridge spacing for narrow ridge single row planting is 66 cm, and the plant spacing is 33 cm; the ridge spacing for wide ridge double row planting is 85 cm, and the plant spacing is 30 cm × 33 cm. The ridge height is about 20 cm, and the ridges must be carefully formed to ensure that the ridge surface is flat.

3. Reasonable fertilization

Sweet potato is a fertilizer-loving crop, and to achieve high yields it is necessary to ensure adequate nutrition. Fertilization should be mainly organic fertilizer , supplemented by chemical fertilizer, ensuring an appropriate amount of nitrogen fertilizer, and a combination of phosphorus and potassium fertilizers, with potassium fertilizer as the main focus. In combination with land preparation, apply more than 3,000 kg of decomposed farmyard manure, 15 kg of urea, 50 kg of superphosphate, 25 kg of potassium sulfate or 50-100 kg of wood ash per mu. Pay attention to increasing the application of potassium fertilizer, which will help improve yield and quality. For varieties that grow too vigorously, the amount of nitrogen fertilizer applied must be strictly controlled.

4. Prevention and control of pests and diseases

Controlling underground pests and rodent infestation helps improve seedling survival rate and tuber quality. Generally, 5% chlorpyrifos granules are used, 2.5 kg per mu, evenly spread on the ground surface and deep plowed into the soil. Or use 500 grams of 75% phoxim, add 20 kilograms of moist soil, mix well, and sprinkle it in the holes as you plant the seedlings. You can also use dichlorvos and roasted wheat bran to make poison bait, and pay attention to preventing and controlling rodent infestations.

5. Plant early at the right time

In order to maximize the effect of film covering under low temperatures in early spring, the seedlings should be strong and planted early. The principle is "plant before frost and cover after frost". The weather in early spring is changeable, so when planting early, you must pay attention to preventing frost, burns, and cold. Covering with film can allow planting about 10 days earlier than in the open field. In Guanzhong area, single film planting is suitable for early April, and double film planting can start in late March. When planting sweet potatoes under plastic film, you cannot blindly rush too early. It should start when the ground temperature 10 cm inside the film is stable at 16°C, and the density should be 3000-3500 plants per mu.

6. Spraying herbicides

Spraying herbicides should be done before planting and mulching to avoid damaging the potato seedlings. For each mu, 100 grams of sethoxydim can be mixed with 100 kilograms of water, or 250 grams of lazodim can be mixed with 70 kilograms of water for spraying on the ridge surface. Weeds between rows can be removed with a lethal herbicide after the seedlings have grown. Be careful not to spray on the potato seedlings.

7. Lamination

Planting at the right time is usually done first and then covering with film. In the plateau area, ridges should be made while the soil is still moist, film should be covered in time, planting should be carried out at appropriate temperatures, and seedlings should be released depending on the temperature. In the plateau area, it is advisable to adopt the wide ridge and double row method. When forming ridges in early spring, it is best to make the top of the ridge into an "concave" shape, which is conducive to natural rainfall and moisture replenishment. The quality of film covering should be strictly controlled, and the principle of "covering wet plants but not dry plants, covering fertile plants but not thin plants, covering fine plants but not coarse plants, covering early plants but not late plants" should be adhered to.

8. Field Management

In the early stage, the focus is on promoting growth, in the middle stage, appropriate control is applied, and in the later stage, premature aging is prevented. Cover the film to prevent strong winds and replant missing seedlings in time. For vigorous growing varieties, topping should be done twice when the seedlings are 30 cm and 1 meter long. Watering should be done in small amounts and not too much. Spray fertilizer on the leaves 2-3 times every 10 days before and after row closing. Use 15 kg of water, one packet of sweet potato growth enhancer and 20 g of potassium dihydrogen phosphate per mu, and spray evenly on the leaves. Before and after row closure, plots with high soil fertility and excessive growth should be sprayed with paclobutrazol for chemical control. Strictly control the amount of nitrogen fertilizer and water, increase the application of wood ash, and till the soil between rows. It is not advisable to turn the vines. In the later stage, pay attention to catching the sweet potato hawk moth or spray phoxim for prevention and control. Sweet potatoes grown under plastic film produce tubers early and are seriously damaged by rodents, so attention should be paid to rodent prevention.

9. Timely harvest

Sweet potatoes covered with plastic film are not suitable for storage. Edible potatoes should be harvested and put on the market early and sold at a high price. Starch processing should also be done in time after early harvest before frost.

The above is an introduction to the key points of sweet potato planting . Although sweet potato is a relatively common crop, in order to achieve high yields, you need to master the planting methods to achieve your goal.