Sweet potato planting technology and management methods

As a widely grown and high-yield crop, the harvest of sweet potato is often closely related to field management skills. Many farmers find that the yield and quality of sweet potatoes are not as expected when they harvest, which may be due to improper management methods or timing. Let’s learn about sweet potato planting techniques and management methods.

1. Topdressing management

Sweet potatoes need sufficient nitrogen fertilizer in the early stages of growth to promote stem and leaf growth and plant health. Phosphorus and potassium fertilizers are needed in the middle and late stages of growth to promote more tubers and rapid expansion.

The first topdressing (to promote seedling growth): 3-5 days after planting, apply 3-5 kg ​​of urea per mu for small and weak seedlings, and combine it with root irrigation during drought.

Second topdressing (for strong vines and tubers): About 30 days after planting, apply 10-15 kg of potassium sulfate and 3-5 kg ​​of urea per mu, earlier in arid areas and later in humid areas.

The third topdressing (potato fertilizer): 90-100 days after planting, apply 15-20 kg of potassium sulfate per mu to promote the enlargement of tubers.

Potash fertilizer selection: Use potassium sulfate instead of potassium chloride to maintain high starch content and quality of potato tubers.

Crack fertilizer: When the soil lacks water and fertilizer or shows signs of premature aging, apply crack fertilizer in mid-to-late August, such as potassium dihydrogen phosphate, potassium sulfate, wood ash, etc., and irrigate through the cracks to the roots.

Foliar fertilizer : After the field is closed, spray foliar fertilizer, such as potassium dihydrogen phosphate, calcium, boron, and magnesium fertilizers, to promote tuber formation and swelling and prevent premature aging. The spraying time should be between 9-10 am or 4-6 pm in sunny weather, once every 10 days, for 2-3 times in a row.

Urea water: For plants with weak growth or premature aging, add 0.5-1% urea water when spraying foliar fertilizer.

2. Watering management

Watering should be controlled in the early stage of sweet potato growth (before tubers form) to prevent the soil from being too wet and causing the plants to grow vigorously. In the middle and late stages of growth (after tuber formation), the soil needs to be kept reasonably moist to promote the healthy and rapid expansion of tubers. Avoid soil moisture that is too high or too low, keep it stable, and prevent uneven dryness and wetness from affecting the quality of sweet potatoes.

Keep the soil moist and avoid drought within 45 days after planting. If the plant grows vigorously, control water in time. Increase the frequency of watering when the field is closed or the tubers begin to swell, and water every 7-10 days depending on the soil moisture.

Maintain the moisture of field soil at 60-70%; the soil should be able to clump together when gripped but will scatter when released. Observe the stems and leaves during the high temperatures at noon. If there is no wilting, it means the soil is not lacking in water.

When the temperature is high and drought occurs or the stems and leaves wilt, water the plants in small amounts in the morning and evening to increase humidity. In case of continuous rain or heavy rain, drain the water within 2 hours after the rain to avoid water accumulation, and till the soil in time after the rain.

Stop watering 10-15 days before harvest to allow the tubers to accumulate nutrients. Excessive humidity may cause cracking and rotting.

3. Topping

Topping and pinching can suppress the growth advantage of the top of the plant and promote the transportation and accumulation of nutrients to the underground tubers. Suitable for sweet potato fields with vigorous growth, topping and pinching need to be carried out about 2 times in batches to control vigorous growth.

The first topping is done when the main stem reaches 40-50 cm in length. This should be done when the side vine branches reach 30-40 cm in length.

Operation method: When topping and pinching, pinch off a small section of young and tender new shoots at the top of the main stem (first pinching) or side vine branches (second pinching).

Note: Topping should be done moderately to avoid excessive inhibition of plant growth. Choose sunny weather to help the plants resume growth. Combined with other management measures, such as reasonable fertilization and watering, to achieve the best results.

4. Lifting the seedlings and turning the vines

By lifting the seedlings and turning the vines, aerial adventitious roots are cut off, nutrient consumption is reduced, and nutrients are concentrated and transported to the tubers, thereby improving yield and quality. It is suitable for sweet potato fields with abundant summer rainfall, high soil moisture, sufficient supply of water and fertilizer, and vigorous growth.

The best time is after the field ridges are closed and before the end of August, and it should be completed by the end of August at the latest. After September, avoiding lifting the seedlings and turning the vines. Generally 1-2 times is appropriate, more than 3 times may reduce the yield.

The above is an introduction to some key points in sweet potato planting and management . It is not difficult to achieve high yields of sweet potatoes, as long as everyone learns the planting and management techniques according to local conditions.