High-Yield Cultivation Techniques and Field Management Key Points for Summer Sweet Potato
In recent years, with the deep processing of sweet potato, its own economic value has continued to grow. The planting area of sweet potato has increased year by year, especially the planting area of summer sweet potato has grown even faster. To achieve high yield in summer sweet potato, the following five measures should be taken:
1. Plant at the right time and rush to transplant. Early planting of summer sweet potato can promote early growth, early tuber formation, early ridge closure, and prolong the tuber bulking period. Generally, for summer sweet potato, from June 20 to June 30, for every day of delayed planting, the average yield decreases by 3%. Therefore, summer sweet potato should be planted early by seizing the time, and efforts should be made to finish planting by early July so that the growth period reaches more than 110 days. Only in this way can a relatively high yield be obtained.
2. Build the sweet potato ridges well. Sweet potato ridges are an important factor affecting the yield of summer sweet potato. Therefore, the ridges must be built well. Avoid making ridges after rain, because making ridges after rain causes soil compaction, which is unfavorable for tuber enlargement. Therefore, make ridges on sunny days when the soil is dry, and strive for fluffy, permeable, and short ridges. Fluffy and permeable ridges can increase soil porosity, enhance permeability and water retention capacity; short ridges are conducive to drainage, prevent soil moisture saturation, and can both resist drought and prevent waterlogging while maintaining the air permeability of the ridges.
3. Apply sufficient base fertilizer. The growth period of summer sweet potato is short. Increasing base fertilizer, especially applying good seedling-promoting fertilizer, can promote rapid growth of stems and vines. For stem fertilizer, generally apply 2500-3000 kg of farmyard manure per 1/15 hectare, preferably applying more quick-acting potassium fertilizer such as plant ash, and when making ridges, apply 10-15 kg of diammonium phosphate per 1/15 hectare. To promote early sprouting of sweet potato seedlings, some nitrogen fertilizer can be applied in the planting holes when transplanting, generally 3-4 kg per 1/15 hectare. Pay attention to keeping seedlings and fertilizer separated. Finally, water and seal the holes.
4. Select and plant vine tips. Sweet potato vine tips have well-developed nutrition, strong stress resistance, early rooting, early tuber formation, and high yield. According to experiments, planting summer sweet potato with vine tips increased yield by 14.1% compared with planting vine nodes, by 18.7% compared with planting cold sweet potato sprouts, and by 22% compared with planting heated-cellar sprouts. When planting vine tips, keep the top leaves from drying out, and achieve three points: first, cut vines, plant, and water as you go, to prevent vine leaves from losing water and wilting; second, keep an appropriate number of leaves above ground. If there are 7 leaves and it is a sunny day, when planting in the morning, 3 leaves may be kept and 4 buried; on a cloudy day, when planting in the afternoon, 4 leaves may be kept and 3 buried. It is best to plant in the afternoon or evening; third, water after planting and seal the holes tightly.
5. Reasonable close planting. The yield per plant of summer sweet potato is relatively low, so generally small ridges and close planting are used to give play to the yield-increasing effect of the population and obtain high yield. Varieties with short vines and concentrated tuber formation can be selected, attention should be paid to reasonable close planting, and small-ridge planting should be used. Generally, ridge spacing is 60-70 cm, plant spacing is 15-20 cm, and 5000-6000 plants are planted per 1/15 hectare. Seed potatoes can be planted even more densely, up to 7000 plants. When planting, use short seedlings, insert deeply and plant obliquely, water sufficiently, and seal the holes tightly, so that they recover early, grow early, form tubers early, form many tubers, and achieve high yield.